Hybrid plasma processing apparatus

- TOKYO ELECTRON LIMITED

A hybrid plasma processing apparatus simultaneously utilises capacitively coupled plasma (CCP) and inductively coupled plasma (ICP) sources in a way that operation of the CCP source compliments operation of the ICP source in a most positive way, so the interference between these very different types of sources, a CCP plasma source and an ICP plasma source, is removed, while essential benefits of each of them are positively combined in a single apparatus. This hybrid plasma processing apparatus allows reaching higher plasma density and with higher efficiency than that possible in traditional CCP sources, while the plasma volume, residence time, and the plasma and process non-uniformity are significantly reduced in comparison with that typical for traditional ICP sources.

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Description
CROSS REFERENCE TO RELATED APPLICATIONS

[0001] The present application is related to and claims priority to U.S. provisional serial No. 60/325,188, filed on Sep. 28, 2001, which is herein incorporated by reference in its entirety. The present application is related to U.S. patent application Ser. No. 10/______, Attorney Docket No. 226809US6YA, filed on even date herewith, which claims priority to United States provisional application serial No. 60/325,199 filed on Sep. 28, 2001. Those applications are herein incorporated by reference in their entirety.

FIELD OF THE INVENTION

[0002] The invention relates generally to semiconductor fabrication process plasma sources employing high frequency RF power. More particularly, the invention relates to a hybrid plasma apparatus simultaneously utilizing capacitively coupled plasma (CCP) and inductively coupled plasma (ICP) sources.

BACKGROUND OF THE INVENTION

[0003] Semiconductor fabrication process plasma sources generally employ sources of a few different types, the main ones being the CCP (capacitively coupled plasma) sources and ICP (inductively coupled plasma) sources. Among other widely used types of plasma sources there are microwave plasma sources (including those utilizing the electron-cyclotron resonance), surface wave plasma sources, and helicon plasma sources. The processes using the above mentioned sources include sputter etching, plasma-enhanced chemical etching, plasma-enhanced vapor deposition, ionized sputter deposition, magnetically-enhanced plasma etching, etc. In those sources, the external RF power is transferred to the plasma producing high energy (high temperature) components. This process significantly increases the reaction rates of various etch or deposition processes used for materials processing. Charged particle flow anisotropy, effectively produced by the biased electric potentials, ensures etching and deposition process anisotropy, having significant advantages in materials processing.

[0004] The CCP sources have a number of advantages over other plasma sources, including flat geometry corresponding to the shape of a typical wafer, high homogeneity of applied electric field and, correspondingly, good uniformity of etching or deposition processes, low residence time of importance for high rates of above mentioned processes, and simplicity. At the same time, CCP sources are not as efficient regarding the energy coupling, the plasma damage effects might be of some concern, and the produced plasma density is not as high as in some other plasma sources.

[0005] The ICP sources have their own advantages, mainly bringing the capability of higher plasma density at lower pressure and higher energy efficiency of the source. The disadvantages of ICP sources include requirements for significantly larger plasma volume leading to larger residence times and thus non-optimal rates for etching or deposition processes. The uniformity of the plasma and, correspondingly, etching or deposition, is not as good.

[0006] It is thus advantageous to combine the best properties of the CCP and ICP sources in a single source. There is, however, a difficulty of designing an apparatus capable of accomplishing this approach. The typical CCP configuration, such as the parallel plate diode and triode configurations or the more modern configurations of the CCP sources, such as SCCM (super capacitively coupled module) or DRM (dipole ring magnetron) currently in use by the semiconductor industry, typically use two large area planar electrodes located close and parallel to each other. In that situation, using external coils around the sides to generate ICP-type plasmas is inefficient. On the other hand, the main advantages of the CCP sources mentioned above are not accessible in the ICP sources that cannot use the second electrode similar to that in the CCP source.

[0007] What is required is a method for efficiently combining a CCP source and an ICP source into a hybrid plasma processing system.

BRIEF SUMMARY OF THE INVENTION

[0008] It is an object of the present invention to provide a hybrid plasma processing system comprising a hybrid plasma source comprising at least one CCP source, at least one ICP source, and a Faraday shield, wherein the Faraday shield functions as an electrode in the CCP source and as an electrostatic shield in the ICP source.

[0009] The hybrid plasma processing system for subjecting a target object to a plasma process comprises a process chamber formed in a process vessel; a gas supply system for supplying a process gas or plurality of process gases to the process vessel; an exhaust system for exhausting and controlling pressure in the process chamber; a worktable arranged in the process chamber, the worktable having a work surface for supporting the target object in the process chamber; an inductively coupled plasma (ICP) source for sustaining a plasma during the plasma process; a capacitively coupled plasma (CCP) source for biasing the plasma as well as creating and sustaining the plasma, and providing the ion energy control; and a dual Faraday shield coupled to the ICP source and the CCP source, the dual Faraday shield comprising a first Faraday shield layer and a second Faraday shield layer.

[0010] In the first aspect of the invention, the ICP source comprises an RF antenna for generating an RF electric field for exciting the process gas in the process chamber to convert the process gas into the plasma, the electric field having an electric field direction which is defined essentially by lines of electric force extending substantially parallel to the target object, wherein the dual Faraday shield is arranged between the RF antenna and the work surface, wherein an electrically grounded first Faraday shield layer and electrically grounded second Faraday shield layer provide an electrostatic shield; and a first RF power supply coupled to the RF antenna through a matching unit, the first RF power supply for supplying an RF power to the RF antenna.

[0011] In a second aspect of the invention, the CCP source further comprises a lower electrode (susceptor) arranged within the susceptor worktable; a matching unit coupled to the lower electrode; a second RF power supply coupled to the matching unit; and an upper electrode comprising an electrically grounded first Faraday shield layer and an electrically grounded second Faraday shield layer.

[0012] In a third aspect of the invention, the dual Faraday shield comprises a gas supply pipe coupled to the gas supply system; a plurality of first conductive elements coupled to the gas supply pipe and to the process vessel, at least one of the first conductive elements comprising a gas dispensing orifice for supplying the process gas to the process chamber; and a plurality of second conductive elements coupled to the gas supply pipe and to the process vessel, wherein the first Faraday shield layer comprises a plurality of first conductive elements arranged in a first pattern and the second Faraday shield layer comprises a plurality of second conductive elements arranged in a second pattern which is offset from the first pattern.

[0013] In another embodiment of the present invention, the hybrid plasma processing system includes a dielectric window separating RF antenna from the processing chamber. A single or dual Faraday shield is fully located within the vacuum chamber. In that embodiment, its additional role is also to protect the window from the direct fluxes of plasma particles and various direct depositions on the window. Thus, the two layers of the Faraday shield are shifted one relative to the other so as to limit or prevent a direct look through the shield.

[0014] Yet in another embodiment of the present invention, the hybrid plasma processing system includes a dielectric window, which is located between the two layers of the Faraday shield. In this embodiment, only the bottom Faraday shield layer has gas dispensing orifices.

[0015] Yet in another embodiment of the present invention, the hybrid plasma processing system includes a dielectric window, which is located below the RF antenna and the Faraday shield. In that embodiment, the gas dispensing orifices in the Faraday shield blades are not used, and the processing gas is supplied to the vacuum chamber from its sides (top and bottom can be used as well).

[0016] Yet in another embodiment of the present invention, the hybrid plasma processing system comprises the RF antenna and the dual Faraday shield, all located within the vacuum chamber. In this embodiment, the RF antenna is protected from the direct fluxes of plasma and gas particles by the dual Faraday shield. A lower layer (or both layers) of the Faraday shield have the gas dispensing orifices on their plasma side for uniform gas supply to the wafer.

[0017] Yet in another embodiment of the present invention, the hybrid plasma processing system comprises the RF antenna and the Faraday shield, with the Faraday shield fully integrated within the dielectric window, and the ICP RF antenna being above that window and outside the process chamber.

[0018] Yet in another embodiment of the present invention, the hybrid plasma processing system for subjecting a target object to a plasma process comprises a process chamber formed in a process vessel; a gas dispenser coupled to the process vessel, the gas dispenser providing a process chamber ceiling, wherein the gas dispenser supplies a process gas to the process chamber; a gas supply system coupled to the gas dispenser for supplying the process gas; an exhaust system for exhausting and controlling pressure in the process chamber; a susceptor arranged in the process chamber, the susceptor having a work surface for supporting the target object in the process chamber; an inductively coupled plasma (ICP) source for establishing a plasma during the plasma process; a capacitively coupled plasma (CCP) source for biasing the plasma; and a dual Faraday shield coupled to the ICP source, the CCP source, and the gas dispenser, the dual Faraday shield comprising a first Faraday shield layer and a second Faraday shield layer.

[0019] In yet another embodiment, processing gas is supplied to the process chamber independently of the Faraday shield, while the Faraday shield plays an additional electrical role of the second electrode of a typical CCP system.

[0020] In yet another embodiment of the present invention, to make the Faraday shield work as a second electrode in the parallel plate system, the shield is connected to an RF power supply through a corresponding matching network. The gas shower orifices can be located on the Faraday shield or the processing gas can be supplied to processing chamber independently of the Faraday shield. The RF power supply in question can be a separate power supply or it can be the same power supply that provides RF power to the ICP antenna.

[0021] Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention, and together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention where:

[0023] FIG. 1a is a schematic diagram showing a hybrid plasma processing system according to a preferred embodiment of the present invention;

[0024] FIG. 1b is a schematic diagram showing a hybrid plasma processing system according to an alternate embodiment of the present invention;

[0025] FIG. 1c is a schematic diagram showing a hybrid plasma processing system according to yet another alternate embodiment of the present invention;

[0026] FIG. 1d is a schematic diagram showing a hybrid plasma processing system according to yet another alternate embodiment of the present invention;

[0027] FIG. 1e is a schematic diagram showing a hybrid plasma processing system according to yet another alternate embodiment of the present invention;

[0028] FIG. 1f is a schematic diagram showing a hybrid plasma processing system according to yet another alternate embodiment of the present invention;

[0029] FIG. 1g is a schematic diagram showing a hybrid plasma processing system according to yet another alternate embodiment of the present invention;

[0030] FIG. 2a is a schematic diagram showing a hybrid plasma processing system according to yet another alternate embodiment of the present invention;

[0031] FIG. 2b is a schematic diagram showing a hybrid plasma processing system according to yet another alternate embodiment of the present invention;

[0032] FIG. 2c is a schematic diagram showing a hybrid plasma processing system according to yet another alternate embodiment of the present invention;

[0033] FIG. 3 illustrates a simplified view of a single spiral antenna that can be used in the ICP source part of a hybrid plasma processing system in accordance with a preferred embodiment of the present invention.

[0034] FIG. 4 illustrates a simplified view of a double-spiral antenna that can be used in the ICP source part of a hybrid system in accordance with a preferred embodiment of the present invention.

[0035] FIG. 5a is a simplified view showing an exemplary shield layer that can be used in the Faraday shield corresponding to a single or double-spiral RF antenna in accordance with a preferred embodiment of the present invention.

[0036] FIG. 5b illustrates an enlarged view of a surface of a conductive element used in a dual Faraday shield of FIG. 5a in accordance with a preferred embodiment of the present invention.

[0037] FIG. 6 illustrates a simplified view of a branching RF antenna that can be used as the ICP part of a hybrid system in accordance with an alternate embodiment of the present invention.

[0038] FIG. 7a is a simplified view showing an exemplary shield layer that can be used in the Faraday shield corresponding to a branching RF antenna of FIG. 6 in accordance with an alternate embodiment of the present invention.

[0039] FIG. 7b is a simplified view showing two layers that can be used in the Faraday shield corresponding to a branching RF antenna of FIG. 6 in accordance with an alternate embodiment of the present invention.

[0040] FIG. 8 gives a schematic view of alternate type of RF antenna and the corresponding layer of the Faraday shield in accordance with an alternate embodiment of the present invention.

DETAILED DESCRIPTION OF TH INVENTION

[0041] Embodiments of the present invention will be described hereinafter with reference to the accompanying drawings. In the following description, the constituent elements having substantially the same function and arrangement are denoted by the same reference numerals, and repetitive descriptions will be made only when necessary.

[0042] The role of the Faraday shield is very specific to this invention of a hybrid ICP-CCP plasma processing system. To make the Faraday shield work as a second electrode, similar to that in the traditional parallel plate system, the shield has a solid ground (in a preferred embodiment, in other embodiments it can be connected to a power source) to cover the large area over the wafer. Top and bottom layers of the Faraday shield are shifted one relative to the other to preferentially cover the whole area. Desirably, those layers are located parallel to the wafer and in a relatively close proximity to it (similar as it would be for the second electrode in a typical CCP source). The gas shower orifices, that are usually located on the top electrode in a CCP source, are now located on the blades of the Faraday shield, providing uniform gas supply to the wafer and a very low residence time, which usually was a characteristic of the CCP-type systems only (and not the ICP systems).

[0043] Because of the dual ICP-CCP nature of a hybrid plasma processing system of the present invention, in the main cases considered, the Faraday shield accomplishes at least two roles: it plays a role of the top electrode of a typical CCP system, and it lets the ICP power from the RF antenna go through and couple to the plasma in the process chamber. In addition, the Faraday shield can play other useful roles such as, for example, screening out the non-uniform CCP component of the ICP antenna coupling, shielding the dielectric window (at least partially) from various fluxes going from the plasma, and providing the means for uniform process gas dispensing over the wafer. All these roles impose special requirements on the design of the Faraday shield for the hybrid plasma processing system of the present invention.

[0044] FIG. 1a is a schematic diagram showing a hybrid plasma processing system 100 according to a preferred embodiment of the present invention. As illustrated in FIG. 1a, the geometry of RF antenna, the dielectric window, and the Faraday shield are flat. The dual Faraday shield is grounded and includes the gas dispensing system.

[0045] Hybrid plasma processing system 100 comprises a CCP source and an ICP source. An airtight process chamber 102 of hybrid plasma processing system 100 is constituted by a substantially cylindrical process vessel 104 and top plate 106. Process vessel 104 and top plate 106 are made of a conductive material, such as stainless steel and are grounded through ground line 108.

[0046] Single or dual (preferred embodiment) Faraday shield 140 is located between ICP RF antenna 110 and a work table 123 with a wafer W.

[0047] In a preferred embodiment, dual Faraday shield 140 is mechanically and electrically coupled to the sidewalls of process vessel 104 and is grounded via a low resistive path 148. Dual Faraday shield 140 comprises first Faraday shield layer 141 and second Faraday shield layer 142.

[0048] In a preferred embodiment, first Faraday shield layer comprises a number of first conductive elements 145 and spaces 147 arranged in a first pattern, and second Faraday shield layer comprises a number of second conductive elements 146 and spaces 149 arranged in a second pattern. Conductive elements 145, 146 are connected to a low-resistivity ground path 148. In this manner, first Faraday shield layer 141 and second Faraday shield layer 142 are electrically grounded and can be used as a grounded upper electrode in a CCP part of the hybrid plasma source.

[0049] In the dual Faraday shield, first conductive elements in first Faraday shield layer 141 are shifted relative to the second conductive elements in second Faraday shield layer 142, thus providing improved electrostatic shielding and improved dielectric window protection from the gas and plasma particle fluxes and depositions

[0050] In addition, first Faraday shield layer 141 and/or second Faraday shield layer 142 can be DC biased, or a RF power can be applied to first Faraday shield layer 141 and/or second Faraday shield layer 142.

[0051] First isolation layer 150 provides a separation distance between the top of first Faraday shield layer 141 and the bottom of second Faraday shield layer 142 to ensure that the conductive elements of first Faraday shield layer 141 are isolated from the conductive elements of second Faraday shield layer 142.

[0052] In a preferred embodiment, first isolation layer 150 is empty. In alternate embodiments, first isolation layer 150 can be filled with dielectric (non-conductive) material.

[0053] Dielectric window 155 is coupled to process vessel 104 and provides a ceiling for process chamber 102. Desirably, dielectric window 155 comprises a dielectric material and provides a dielectric window for antenna 110. In alternate embodiments, a second isolation layer can be provided between dielectric window 155 and Faraday shield 140.

[0054] In a preferred embodiment, gas supply lines 133 are coupled to first Faraday shield layer 141 and to second Faraday shield layer 142 which are used to supply processing gas to chamber 102. Gas supply lines 133 are coupled to gas source unit 134 through at least one opening/closing valve (not shown) and at least one flow control valve (not shown). The gas source unit 134 has gas sources for a plurality of different gases to be supplied to process chamber 102, e.g., CF4, C4 F8, CO, O2, Ar, and N2.

[0055] In the illustrated embodiment, gas source unit 134 is independently coupled to the Faraday shield layers such that first Faraday shield layer 141 and second Faraday shield layer 142 can be used independently to supply one or more different gases to process chamber 102. In other embodiments, gas source unit 134 can be coupled to either first Faraday shield layer 141 or second Faraday shield layer 142, in which case only one Faraday shield layer is used to supply processing gas to process chamber 102.

[0056] A radio frequency (RF) antenna 110 is arranged on top of dual Faraday shield 140. In a preferred embodiment, RF antenna is configured as a single spiral antenna (FIG. 3). In alternate embodiments, other antenna configurations (see below) can be used.

[0057] RF antenna 110 is connected through the port 130 and through the transmission line 113 and matching unit 112 to a first RF power supply 114. Desirably, first RF power supply 114 outputs RF power for the ICP source enough to produce a plasma in the process chamber and operates in a RF frequency range of 10-1000 MHz.

[0058] Susceptor 116 comprises a conductive material and is arranged in the lower portion of the process chamber 102. In preferred embodiment (FIG. 1a), the susceptor is under RF potential supplied by a second RF power supply 126 through the corresponding matching network 124. The RF frequency of the second RF power supply 126 is in the range of 100 kHz-10 MHz. This provides additional biasing potential on the wafer W and improves directionality of charged particle fluxes going from the plasma (not shown) to the wafer W.

[0059] The upper surface of the susceptor 116 serves as a wafer-holding surface and an insulating layer 115 made of, e.g., polyimide is adhered to the upper surface. On the insulating layer 115, a conductive electrostatic chuck electrode 117 and a resistive layer 121 are arranged. The chuck electrode can be prepared by forming a silver or palladium film on the lower surface of the resistive layer. A conductive line (not shown) covered by an insulating cable is provided in the susceptor and connected to the chuck electrode 117. On the other end, this conductive line is connected to a DC power supply through a switch (not shown).

[0060] The susceptor is mounted on the cooling block 119 made of a thermo-conductive material such as aluminum, which carries tubes with circulating coolant such as liquid nitrogen. The cooling block 119 is coupled to the bottom part of the process chamber through an insulating member 118.

[0061] An elevating shaft 120 is movable in the vertical direction by the elevating mechanism (not shown). It is designed to move the entirety of the work table 123 including susceptor 116, electrostatic chuck 117, cooling block 119, as well as the wafer W, in vertical direction, so the distance between the wafer W and the ICP RF antenna 110 can be properly adjusted.

[0062] Bellows 122 comprises an airtight member. Bellows 122 is coupled to insulating member 118, surrounds elevating shaft 120, and is coupled to the bottom surface of process chamber 102. Hence, even if the susceptor 116 is moved vertically, the airtightness in process chamber 102 is not impaired.

[0063] Process chamber 102 is connected to exhaust line 136 of an exhaust system. Exhaust line 136 is connected to exhaust pump 138 through an opening/closing valve and a flow control valve (not shown). Exhaust pump 138 can exhaust process chamber 102 and set process chamber 102 at a vacuum of, e.g., from 1 mTorr to 500 mTorr.

[0064] In a preferred embodiment, controller 170 is coupled to first RF power supply 114, first matching network 112, second RF power supply 126, second matching network 124, gas source 134, and exhaust pump 138. Controller 170 comprises hardware and software to control the operation of first RF power supply 114, second RF power supply 126, gas source 134, and exhaust pump 138. For example, controller 170 can control the frequency, phase, amplitude, and bias of the signals provided by the RF power supplies. In addition, controller 170 can control process gas and flow rate through the Faraday shield 140. Also controller 170 can control the temperature of the Faraday shield 140 by controlling the flow of fluids through conductive elements 145, 146.

[0065] In hybrid plasma processing system 100 shown in FIG. 1a, a process is performed as follows. First, wafer W is placed on the worktable 123 arranged in process chamber 102. Subsequently, process chamber 102 is exhausted by the exhaust system connected to process chamber 102, thereby setting the entire interior of process chamber 102 to a predetermined pressure-reduced atmosphere.

[0066] Worktable 123 with wafer W is moved vertically to the working position, so the distance between the wafer W and the RF antenna 110 is set to predetermined value defined by the process.

[0067] While process chamber 102 is continuously exhausted, a process gas is supplied from process gas supply system 134 to process chamber 102. In a preferred embodiment, the process gas is provided from gas supply system to at least one gas supply pipe, and from the at least one gas supply pipe to dual Faraday shield 140. Process gas enters process chamber 102 from dual Faraday shield 140 through gas supply holes (not shown in FIG. 1a).

[0068] In this state, a plasma generating RF power is provided by the ICP source utilizing RF power from power supply 114, so that the process gas supplied to process chamber 102 is excited, dissociated, and ionized, thereby generating a plasma

[0069] Simultaneously, a secondary RF power is provided by the CCP source utilizing power supply 126. This process generates an RF electric field in the process chamber 102 mostly in a perpendicular direction to that generated by the ICP source. The combined ICP-CCP electric field is higher than that provided separately by ICP and CCP sources, which results in a higher plasma density in a CCP-like system.

[0070] In addition, RF power, provided by the CCP source, enhances DC bias of the plasma and guides the plasma ions onto the surface of wafer W, thereby more efficiently etching wafer W.

[0071] In a preferred embodiment, during processing the distance between wafer W and dual Faraday shield 140 is kept constant in order to ensure a high uniformity of the process on wafer W. Since wafer W is horizontally placed on the horizontal surface of susceptor 116, dual Faraday shield 140 is also horizontally arranged.

[0072] At significant RF powers, to control the temperature of Faraday shield, it might be advantageous to provide cooling channels carrying tubes with circulating coolant through the conductive elements of Faraday shield.

[0073] FIG. 1b is a schematic diagram showing a hybrid plasma processing system according to an alternate embodiment of the present invention. In the illustrated embodiment, processing gas is supplied to the process chamber 102 instead of being coupled to the dual Faraday shield 140. Gas supply lines 133 are coupled to gas source unit 134 through at least one opening/closing valve (not shown) and at least one flow control valve (not shown). The gas source unit 134 has gas sources for a plurality of different gases to be supplied to process chamber 102.

[0074] FIG. 1c is a schematic diagram showing a hybrid plasma processing system according to yet another alternate embodiment of the present invention. In the illustrated embodiment, only a single layer of the Faraday shield 140 is located within the process chamber and below the dielectric window. Alternately, layer 141 can be omitted. In addition, gas source unit 134 is coupled to second layer 142 of the Faraday shield 140, and possibly, directly to the process chamber 102.

[0075] FIG. 1d is a schematic diagram showing a hybrid plasma processing system according to yet another alternate embodiment of the present invention. In the illustrated embodiment, ICP RF antenna 110 and Faraday shield 140 are located within the process chamber 102. In addition, gas source unit 134 is coupled to the dual Faraday shield 140.

[0076] FIG. 1e is a schematic diagram showing a hybrid plasma processing system according to yet another alternate embodiment of the present invention. In the illustrated embodiment, geometry of RF antenna 110 and dielectric window 155 is dome-shaped, while geometry of the Faraday shield 140 is flat.

[0077] FIG. 1f is a schematic diagram showing a hybrid plasma processing system according to yet another alternate embodiment of the present invention. In the illustrated embodiment, geometries of the RF antenna 110, the dielectric window 155, and the first layer 141 of the dual Faraday shield 140 are dome-shaped, while geometry of the second layer 142 of the Faraday shield 140 is flat. In this case, the gas source unit 134 can be coupled to both layers 141 and 142 of the dual Faraday shield 140, or it can be coupled to the second layer 142 and/or directly to the process chamber 102.

[0078] FIG. 1g is a schematic diagram showing a hybrid plasma processing system according to yet another alternate embodiment of the present invention. In the illustrated embodiment, geometries of RF antenna 110, dielectric window 155, and the Faraday shield 140 are non-flat (dome-shaped in this illustration).

[0079] FIG. 2a is a schematic diagram showing a hybrid plasma processing system 200 according to yet another alternate embodiment of the present invention. Hybrid plasma processing system 200 comprises a CCP source and an ICP source. In FIG. 2a, Faraday shield 240 is connected to a separate RF power supply.

[0080] An airtight process chamber 202 of hybrid plasma processing system 200 is constituted by a substantially cylindrical process vessel 204 and top plate 206. Process vessel 204 and top plate 206 are made of a conductive material, such as stainless steel and are grounded through ground line 208.

[0081] Single or dual (desirable configuration) Faraday shield 240 is located between ICP RF antenna 210 and a worktable 223 with a wafer W.

[0082] In the illustrated embodiment, dual Faraday shield 240 is mechanically and electrically coupled to the sidewalls of process vessel 204 and is grounded via a low resistive path 248. Dual Faraday shield 240 comprises first Faraday shield layer 241 and second Faraday shield layer 242.

[0083] In the illustrated embodiment, first Faraday shield layer comprises a number of first conductive elements 245 and spaces 247 arranged in a first pattern, and second Faraday shield layer comprises a number of second conductive elements 246 and spaces 249 arranged in a second pattern.

[0084] Faraday shield 240 is connected to a separate RF power supply 254 through the transmission line 253 and matching network 252. The RF frequency of the power supply 254 is in the range of 10-1000 MHz and is higher than RF frequency on the susceptor 216 provided by power supply 226. This embodiment shifts the illustrated hybrid plasma processing system to being more of the CCP type than the ICP type. Nevertheless, the ICP component of the RF electric field is of great importance and provides ways to increase plasma density at given gas pressure.

[0085] Dielectric window 255 is coupled to process vessel 204 and provides a ceiling for process chamber 202. Desirably, dielectric window 255 comprises a dielectric material and provides a dielectric window for antenna 210. In alternate embodiments, a second isolation layer can be provided between dielectric window 255 and Faraday shield 140.

[0086] In FIG. 2a, gas supply lines 233 are coupled to first Faraday shield layer 241 and to second Faraday shield layer 242 which are used to supply processing gas to chamber 202. Gas supply lines 233 are coupled to gas source unit 234 through at least one opening/closing valve (not shown) and at least one flow control valve (not shown). The gas source unit 234 has gas sources for a plurality of different gases to be supplied to process chamber 202, e.g., CF4, C4 F8, CO, O2, Ar, and N2.

[0087] In the illustrated embodiment, gas source unit 234 is independently coupled to the Faraday shield layers such that first Faraday shield layer 241 and second Faraday shield layer 242 can be used independently to supply one or more different gases to process chamber 202. In other embodiments, gas source unit 234 can be coupled to either first Faraday shield layer 241 or second Faraday shield layer 242, or directly to the process chamber 202.

[0088] An ICP RF antenna 210 is arranged on top of dual Faraday shield 240. In the illustrated embodiment, RF antenna is configured as a single spiral antenna (FIG. 3). In alternate embodiments, other antenna configurations (see below) can be used.

[0089] ICP RF antenna 210 is connected through the port 230 and through the transmission line 213 and matching unit 212 to a first RF power supply 214. Desirably, first RF power supply 214 outputs RF power for the ICP source and operates in a RF frequency range of 10-1000 MHz.

[0090] Susceptor 216 comprises a conductive material and is arranged in the lower portion of the process chamber 202. In preferred embodiment (FIG. 2a), the susceptor is under RF potential supplied by a second RF power supply 226 through the corresponding matching network 224. The RE frequency of the second RF power supply 226 is in the range of 100 kHz-10 MHz. This provides additional biasing potential on the wafer W and improves directionality of charged particle fluxes going from the plasma (not shown) to the wafer W.

[0091] The upper surface of the susceptor 216 serves as a wafer-holding surface and an insulating layer 215 made of, e.g., polyimide is adhered to the upper surface. On the isolative layer 215, a conductive electrostatic chuck electrode 217 and a resistive layer 221 are arranged. The chuck electrode can be prepared by forming a silver or palladium film on the lower surface of the resistive layer. A conductive line (not shown) covered by an insulating cable is provided in the susceptor and connected to the chuck electrode 217. On the other end, this conductive line is connected to a DC power supply through a switch (not shown).

[0092] The susceptor is mounted on the cooling block 219 made of a thermo-conductive material such as aluminum, which carries tubes with circulating coolant such as liquid nitrogen. The cooling block 219 is coupled to the bottom part of the process chamber through an insulating member 218.

[0093] An elevating shaft 220 is movable in the vertical direction by the elevating mechanism (not shown). It is designed to move the entirety of the work table 223 including susceptor 216, electrostatic chuck 217, cooling block 219, as well as the wafer W, in vertical direction, so the distance between the wafer W and the ICP RF antenna 210 can be properly adjusted.

[0094] Bellows 222 comprises an airtight member. Bellows 222 is coupled to insulating member 218, surrounds elevating shaft 220, and is coupled to the bottom surface of process chamber 202. Hence, even if the susceptor 216 is moved vertically, the airtightness in process chamber 202 is not impaired.

[0095] Process chamber 202 is connected to exhaust line 236 of an exhaust system. Exhaust line 236 is connected to exhaust pump 238 through an opening/closing valve and a flow control valve (not shown). Exhaust pump 238 can exhaust process chamber 202 and set process chamber 202 at a vacuum of, e.g., from 5 mTorr to 500 mTorr.

[0096] In the illustrated embodiment, controller 270 is coupled to first RF power supply 214, first matching network 212, second RF power supply 226, second matching network 224, third RF power supply 254, third matching network 252, gas source 234, and exhaust pump 238. Controller 270 comprises hardware and software to control the operation of first RF power supply 214, second RE power supply 226, third power supply 254, gas source 234, and exhaust pump 238. For example, controller 270 can control the frequency, phase, amplitude, and bias of the signals provided by the RF power supplies. In addition, controller 270 can control process gas and flow rate through the Faraday shield 240 and to the process chamber 202. Also controller 270 can control the temperature of the Faraday shield 240 by controlling the flow of fluids through conductive elements 245, 246.

[0097] In hybrid plasma processing system 200, a process is performed as follows. First, wafer W is placed on the worktable 223 arranged in process chamber 202. Subsequently, process chamber 202 is exhausted by the exhaust system connected to process chamber 202, thereby setting the entire interior of process chamber 202 to a predetermined pressure-reduced atmosphere.

[0098] Worktable 223 with wafer W is moved vertically to the working position, so the distance between the wafer W and the RF antenna 210 is set to predetermined value defined by the process.

[0099] While process chamber 202 is continuously exhausted, a process gas is supplied from process gas supply system 234 to process chamber 202. In a preferred embodiment, the process gas is provided from gas supply system to at least one gas supply pipe, and from the at least one gas supply pipe to dual Faraday shield 240. Process gas enters process chamber 202 from dual Faraday shield 240 through gas supply holes (not shown in FIG. 2a).

[0100] In this state, a plasma generating RF power is provided by the ICP source utilizing RF power from power supply 214, so that the process gas supplied to process chamber 202 is excited, dissociated, and ionized, thereby generating a plasma.

[0101] Simultaneously, a secondary RF power is provided by the CCP source utilizing power supply 226 and power supply 254. This process generates RF electric field in the process chamber 202 mostly in perpendicular direction to that generated by the ICP source. Combined ICP-CCP electric field is higher than that provided separately by each of ICP and CCP sources, which results in a higher plasma density and in alternating other characteristics of the plasma source.

[0102] FIG. 2b is a schematic diagram showing a hybrid plasma processing system according to yet another alternate embodiment of the present invention. In this embodiment, Faraday shield 240 is connected to the same RF power supply 214 as RF antenna. However, it utilizes a different transmission line 263, different matching network 262 and an RF regulator 264. The RF regulator 264 is capable of regulating attenuation of transmitted RF power and phase shifting. As illustrated in FIG. 2b, the RF power to the Faraday shield is coupled directly through the dielectric window. Other options, when RF power is coupled to the Faraday shield through the process chamber (similar to that shown in FIG. 2a) are envisioned and covered by this invention as well.

[0103] Many other embodiments, similar to those illustrated in FIG. 1a-1g, such for example as using non-flat geometries for ICP RF antenna, for dielectric window and for one or two layers of the Faraday shield, can be implemented in a situation with the RF power supplied to the Faraday shield similar to how they were implemented in a situation with the grounded Faraday shield. Thus, there is no need in providing additional figures to illustrate those possibilities, and all those embodiments are also covered by the present invention.

[0104] FIG. 2c is a schematic diagram showing a hybrid plasma processing system according to yet another alternate embodiment of the present invention. In this embodiment, the dielectric window is absent, and ICP RF antenna is protected from plasma fluxes by the dual Faraday shield only. As illustrated, the Faraday shield 240 is connected to a separate RF power supply 252 via transmission line 253. Alternate embodiments are envisioned as well, when the same RF supply 214 provides RF power to ICP RF antenna 210 and to the Faraday shield 240. For example, a different matching network 262 and regulator 264 can be used, similar to that shown in FIG. 2b.

[0105] Different types of RF antennas can be used in the ICP source, which is a part of the hybrid plasma source under present invention. There is a direct correspondence between the type of ICP RF antenna and the Faraday shield type that can be simultaneously used in a hybrid plasma source. Here, we mention just a few main types of RF antennas and the corresponding Faraday shields, but the present hybrid plasma processing system invention should be kept valid for the other properly chosen antenna-shield couples.

[0106] FIG. 3 illustrates a simplified view of a single spiral RF antenna 300 that can be used in the ICP source part of the hybrid plasma processing system in accordance with a preferred embodiment of the present invention. Antenna blade 310 comprises a spiral pattern having a number of turns, a first end 312, and a second end 314. The two ends, 312 and 314, of the antenna blade 310, are subject of RF potential difference. In a preferred embodiment, RF power is supplied to end 312 and end 314 is grounded. Alternately, end 312 can be grounded, while supplying RF power to end 314. Other possibilities include supplying 180 degrees shifted RF potentials to the ends 312 and 314, such as coming from a push-pull type of RF power supply. RF antenna blade 310 covers at least the area over the wafer W, so the plasma is uniformly generated in the process chamber.

[0107] FIG. 4 illustrates a simplified view of a double-spiral antenna, advantageous for covering larger areas, that can be used in the ICP source part of a hybrid system in accordance with a preferred embodiment of the present invention. Two antenna blades, 410 and 420, start, respectively, at center points 412 and 414, and end at the periphery points 414 and 424. The antenna blades cover at least the area over the wafer W, so the plasma is uniformly generated in the process chamber.

[0108] Different power feeding of the RF antenna 400 is envisioned. In one embodiment, which we call synchronous, the similar RF potentials are applied to both starting points, 412 and 422, of the two antenna blades, 410 and 420, as well as similar RF potentials (for example, ground) are applied to the other ends, 414 and 424. In this case, the situation is similar to feeding a single spiral antenna 300 described above. Those skilled in the art will recognize that other feeding possibilities exist which would directly correspond to that of a single-spiral antenna

[0109] In another embodiment, which we call asynchronous, the RF potentials, applied to the corresponding end points of two blades of the dual-spiral antenna, have a phase shift (preferentially, 180 degrees). For example, the RF potentials applied to the starting points 412 and 414 are out of phase (have the phase shift of 180 degrees). The other antenna ends, 414 and 424, can be grounded directly or through the corresponding capacitors. This would provide the spiral electromagnetic wave penetration from the center to periphery and efficient uniform plasma generation in the process chamber, even for larger areas. Other types of antenna feeding are envisioned as well, for example, those where the starting and ending points are switched, or where a push-pull type of power supply is used, similar to that described above for a single spiral antenna.

[0110] In order to prevent dual Faraday shield 140 (FIG. 1) from being inductively heated, and to effectively use the input energy form the RF antenna 110 for generating the plasma, no electric current passageway should be formed in any direction which is the same as that of an RF electric field. In a preferred embodiment, the RF antenna 110 is formed of a single or double-spiral coil that is arranged to have a geometric center aligning with that of wafer W placed on the susceptor 116. Consequently, the RF electric field generated by RF antenna 110 has an electric field direction defined mainly by lines of electric force concentrically surrounding the center.

[0111] For this reason, dual Faraday shield 140 is provided with a number of conductive elements 145, 146 which are arranged essentially radial and equidistant. The center of dual Faraday shield 140 aligns with the geometric centers of the RF antenna 110 and wafer W placed on susceptor 116. In other words, conductive elements 145, 146 extend in directions that are substantially perpendicular to the direction of the RF electric field generated by RF antenna 110. With this arrangement, the electromagnetic field generated by RF antenna 110 is transmitted into process chamber 102 without being cut off, so that the RF electric field is generated in process chamber 102, while capacitive component is considerably reduced. As a result, the input energy from RF antenna 110 is effectively used for generating the plasma

[0112] In order to decrease thermal stresses, first Faraday shield layer 141, second Faraday shield layer 142, and gas pipes 133 are set to have coefficients of thermal expansion close to each other.

[0113] FIG. 5a is a simplified view showing an exemplary shield layer that is used in dual Faraday shield 140 in accordance with a preferred embodiment of the present invention.

[0114] Conductive elements 505 are radially arranged relative to center element 540. In a preferred embodiment, center element 540 is defined by gas pipe 132. Conductive elements are separated by spaces 510 that have separation angular width 512. Conductive elements 505 have an element angular width 522. Conductive elements 505 are electrically connected to the ground (first embodiment) or to the RF power supply (second embodiment).

[0115] First Faraday shield layer 141 (FIG. 1a) comprises a first number of conductive elements 505 arranged in a first pattern. Second Faraday shield layer 142 (FIG. 1a) comprises a second number of conductive elements 505 arranged in a second pattern.

[0116] In a preferred embodiment, the first number of conductive elements 505 is determined by N1=360/(first conductive element angular width+first separation angular width), and the number of spaces 210 is also equal to N1. The spacing angular width 512 is substantially equal to the element's angular width 522. In alternate embodiments, element angular width 522 can be different than separation angular width 512.

[0117] The second number of conductive elements 505 (not shown in FIG. 5) is determined by N2=360/(second conductive element angular width+second separation angular width), and the number of spaces is also equal to N2. In a preferred embodiment, the element's angular width 505 is substantially the same for both shield layers (141, 142; FIG. 1a), and the first and second patterns are offset by an angle offset that is substantially equal to the element's angular width 522. In alternate embodiments, element angular width 522 can be different than separation angular width 512 for the second number of conductive elements 505. Also, the element angular widths and the separations can be different in the different shield layers.

[0118] In a preferred embodiment, spaces 510 are empty. In alternate embodiments, spaces 510 can be filled with dielectric (non-conductive) material.

[0119] Conductive elements 505 are fabricated using a metal such as anodized aluminum. For example, conductive elements 505 can have a single conductive surface that can be fabricated using a metal such as anodized aluminum. Conductive elements 505 can be fabricated differently for the different shield layers.

[0120] In a preferred embodiment, the first pattern of conductive elements 505 of the first layer 141 and the second pattern of conductive elements 505 of the second layer 142 are coupled to gas pipe 133 (FIG. 1a). In alternate embodiments, the first pattern of conductive elements 505 or the second pattern of conductive elements 505 is coupled to gas pipe 133. Yet in other alternate embodiments, the gas pipe is not coupled to the conductive elements of the Faraday shield and the process gas is supplied to the process chamber by other means.

[0121] FIG. 5b illustrates an enlarged view of a surface of a conductive element 505 used in a Faraday shield of FIG. 5a in accordance with a preferred embodiment of the present invention.

[0122] In the illustrated embodiment, conductive elements 505 are substantially pie-shaped, and coupled to center element 540. In a preferred embodiment, bottom surface of conductive element 505 comprises at least one gas dispensing orifice 530 as shown in FIG. 5b.

[0123] There are numerous embodiments on how the process gas can be supplied to conductive elements 505 of the Faraday shield 140 and how the gas flow is provided. In preferred embodiment, the gas pipe connectors 550 are located near the periphery 504 of each conductive element 505. Each gas pipe connector 550 provides a gas inlet into the Faraday shield, while orifices 530 on the lower part of conductive elements 505 provide gas outlets from the Faraday shield 140 (which are, at the same time, gas inlets for the process chamber 102, FIG. 1a). Both layers, 141 and 142, of the Faraday shield 140 have independent gas pipe systems.

[0124] In alternate embodiments, both layers of the Faraday shield have a common gas supply system.

[0125] In yet other alternate embodiments, only a single layer, 141 or 142, of the Faraday shield is coupled to the gas source unit 134.

[0126] In yet another alternate embodiment, the gas source unit 134 is not coupled to conductive elements 505 of the Faraday shield, but is coupled to the process chamber 102 via other means.

[0127] In yet another alternate embodiment, the gas pipe connectors 550 at the periphery of conductive elements 505 are absent and the process gas is supplied to the gas connector located at the center element 540.

[0128] Conductive elements 505 in first Faraday shield layer 141 and second Faraday shield layer 142 are either electrically grounded (FIG. 1a), or under electric potential (FIG. 2a) provided by an RF power supply, as was discussed above. Desirably, the capacitive coupling between the ICP RF antenna and the plasma is broken off by the Faraday shield.

[0129] FIG. 6 illustrates a simplified view of a branching RF antenna 600 that can be used as the ICP part of a hybrid system in accordance with an alternate embodiment of the present invention. In conjunction with the system described in the co-pending U.S. patent application Ser. No. 10/______, Attorney Docket No. 226809US6YA, filed on even date herewith, entitled “BRANCHING RF ANTENNAS AND PLASMA PROCESSING APPARATUS”, the contents of which are incorporated herein by reference, a number of different branching antenna configurations can be used with the present invention. For example, a radial type of the branching antenna can be used. This antenna 600 comprises a number of major 608 and minor 610 branches with the cooling channels 612. Major branches 608 go from the center element 602 and up to the branching point 614, where the minor branches split and go to the periphery ends 606. In addition, there are alternate means for feeding the branching RF antenna 600. In one embodiment, RF power is supplied to the center feed located at the center element 602, while the end 606 are grounded directly or through the corresponding capacitors.

[0130] The radial type branching RF antenna 600 carries RF currents preferentially in the radial direction. Correspondingly, conductive elements of the Faraday shield, corresponding to this antenna, extend mainly in the azimuthal direction. The possible Faraday shield for this case is illustrated in FIG. 7a and FIG. 7b.

[0131] FIG. 7a is a simplified view showing an exemplary shield layer 705 of the spiral Faraday shield to be used with the radial branching RF antenna 600 in the hybrid plasma source according to alternate embodiment of the present invention. The shield layer 705 comprises a spiral pattern having a number of turns, a first end 710, and a second end 720.

[0132] A set of gas dispensing orifices 730 is located on the lower side (plasma side) of the Faraday shield.

[0133] In preferred embodiment, the dual Faraday shield 140 consists of two shield layers, 141 and 142, which for the case of spiral pattern are illustrated in FIG. 7b. Here, two spiral patterns, 705 and 745, for this two layers compliment each other to cover substantially the area over the wafer W. The two spiral patterns desirably prevent the look through, and have gas dispensing orifices, 730 and 760, on the bottom sides (plasma sides). In alternate embodiments, only one shield layer has the gas dispensing orifices, or they are absent on both layers and the gas in supplied to process chamber via different means.

[0134] The Faraday shield layers are connected in a manner to provide the same electric potential through the whole area of the shield. In some embodiments, the Faraday shield layers are grounded, as shown above (FIG. 1a-1g). In other embodiments, an RF potential is applied to the Faraday shield (see FIG. 2a-2c).

[0135] The are many other alternate embodiments for designing of ICP RF antenna and Faraday shield that can be used for the hybrid plasma processing apparatus of the present invention.

[0136] FIG. 8 shows a schematic view of alternate type of RF antenna and the corresponding layer of the Faraday shield in accordance with another alternate embodiment of the present invention. In FIG. 8, the RF antenna blade 805 comprises first end 810 and second end 820 and has a zigzag form. The Faraday shield layer 815 with the first end 830 and the second end 840 forms a complimentary zigzag, so the local directions of RF antenna and Faraday shield blades are substantially perpendicular to each other. This arrangement provides the required functionality of the antenna-Faraday shield complementary pair.

[0137] Desirably, RF antenna blades and Faraday shield layers are flat. Alternately, some or all of them are arranged on curved (dome-shaped, for example) surfaces.

[0138] The present invention can be applied to a plasma processing apparatus other than an etching apparatus, e.g., a film-forming apparatus or an ashing apparatus. The present invention can also be applied to a plasma processing apparatus for a target object other than a semiconductor wafer, e.g., an LCD glass substrate. Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

Claims

1. A hybrid plasma processing system for subjecting a target object to a plasma process, said system comprising:

process chamber formed in a process vessel;
gas supply system for supplying a process gas to said process chamber;
exhaust system for exhausting and controlling pressure in said process chamber;
susceptor arranged in said process chamber, said susceptor having a work surface for supporting said target object in said process chamber; and
hybrid plasma source comprising at least one inductively coupled plasma (ICP) source, at least one capacitively coupled plasma (CCP) source, and Faraday shield coupled to said ICP source and said CCP source, said hybrid source for establishing a plasma and for biasing said plasma during said plasma process, wherein said Faraday shield comprises a plurality of conductive elements, said Faraday shield providing at least one electrode in said CCP source and providing at least one shield in said ICP source.

2. The hybrid plasma processing system as claimed in claim 1, wherein said ICP source further comprises:

RF antenna for generating an RF field in said process chamber to convert said process gas into said plasma, said RF field having an electric field component, which is defined essentially by lines of electric force extending substantially parallel to said target object; and
first RF power supply coupled to said RF antenna through a first matching unit, said first RF power supply for supplying an RF power to said RF antenna,
wherein said Faraday shield is arranged between said RF antenna and said work surface, said Faraday shield attenuating the electrostatic field component while being substantially transparent to the electromagnetic field component of said RF antenna.

3. The hybrid plasma processing system as claimed in claim 2, wherein said RF antenna and said Faraday shield are arranged within said process vessel.

4. The hybrid plasma processing system as claimed in claim 2, further comprising at least one dielectric window arranged between said RF antenna and said Faraday shield.

5. The hybrid plasma processing system as claimed in claim 1, wherein said CCP source further comprises:

lower electrode arranged within said susceptor;
matching unit coupled to said lower electrode;
second RF power supply coupled to said matching unit; and
upper electrode comprising said at least one electrode coupled to ground.

6. The hybrid plasma processing system as claimed in claim 1, wherein said Faraday shield further comprises gas supply pipe coupled to said gas supply system, wherein at least one conductive element is coupled to said gas supply pipe, said at least one conductive element being arranged with said process chamber and comprising at least one gas dispensing orifice for supplying said process gas to said process chamber.

7. The hybrid plasma processing system as claimed in claim 1, wherein said Faraday shield comprising a first Faraday shield layer and a second Faraday shield layer, said first Faraday shield layer comprising a plurality of first conductive elements arranged in a first pattern and said second Faraday shield layer comprises a plurality of second conductive elements arranged in a second pattern which is offset from said first pattern.

8. The hybrid plasma processing system as claimed in claim 7, wherein said Faraday shield further comprises a first isolation layer arranged between said first Faraday shield layer and said second Faraday shield layer, wherein said first isolation layer provides a separation distance between conductive elements of said first Faraday shield layer and conductive elements of said second Faraday shield layer.

9. The hybrid plasma processing system as claimed in claim 7, wherein said Faraday shield further comprises gas supply pipe coupled to said gas supply system, wherein at least one first conductive element is coupled to said gas supply pipe, said at least one first conductive element being arranged within said process chamber and comprising at least one gas dispensing orifice for supplying said process gas to said process chamber.

10. The hybrid plasma processing system as claimed in claim 9, wherein at least one second conductive element is coupled to said gas supply pipe, said at least one second conductive element being arranged with said process chamber and comprising at least one gas dispensing orifice for supplying said process gas to said process chamber.

11. The hybrid plasma processing system as claimed in claim 7, wherein said Faraday shield further comprises gas supply pipe coupled to said gas supply system, wherein at least one second conductive element is coupled to said gas supply pipe, said at least one second conductive element being arranged within said process chamber and comprising at least one gas dispensing orifice for supplying said process gas to said process chamber.

12. The hybrid plasma processing system as claimed in claim 7, further comprising a dielectric window arranged between said first Faraday shield layer and said second Faraday shield layer.

13. The hybrid plasma processing system as claimed in claim 7, wherein at least one said first conductive element is coupled to ground.

14. The hybrid plasma processing system as claimed in claim 13, wherein at least one said second conductive element is coupled to ground.

15. The hybrid plasma processing system as claimed in claim 7, wherein at least one said second conductive element is coupled to ground.

16. The hybrid plasma processing system as claimed in claim 1, wherein said Faraday shield is coupled to a RF power supply through a matching unit.

17. The hybrid plasma processing system as claimed in claim 2, wherein said Faraday shield is coupled to said first RF power supply through a separate matching unit and regulator; said regulator adapted to control RF power to said Faraday shield.

18. The hybrid plasma processing system as claimed in claim 7, wherein at least one layer of said Faraday shield is integrated within a dielectric window.

19. The hybrid plasma processing system as claimed in claim 2, wherein said RF antenna and said Faraday shield are located within said process chamber.

20. The hybrid plasma processing system as claimed in claim 2, wherein at least one of said RF antenna and said Faraday shield comprises a planar geometry.

21. The hybrid plasma processing system as claimed in claim 2, wherein at least one of said RE antenna and said Faraday shield comprises a non-planar geometry.

22. The hybrid plasma processing system as claimed in claim 2, wherein said RF antenna comprises a single-spiral blade having one end coupled to said first matching unit.

23. The hybrid plasma processing system as claimed in claim 2, wherein said RE antenna comprises a dual-spiral blade, each blade having one end coupled to said first matching unit.

24. The hybrid plasma processing system as claimed in claim 23, wherein said first matching network provides a first signal to a first blade and a second signal to a second blade.

25. The hybrid plasma processing system as claimed in claim 24, wherein said first signal and said second signal are in-phase.

26. The hybrid plasma processing system as claimed in claim 24, wherein said first signal and said second signal are not in-phase.

27. The hybrid plasma processing system as claimed in claim 1, wherein said Faraday shield further comprises a number of said conductive elements radially arranged around a center element, each conductive element being substantially pie-shaped and extending from a center element to a periphery, wherein the number of conductive elements is equal to (three hundred and sixty degrees divided by the sum of a conductive element angular width and a separation angular width).

28. The hybrid plasma processing system as claimed in claim 7, wherein said first pattern comprises a first number of first conductive elements radially arranged around a center element, each first conductive element being substantially pie-shaped and extending from a center element to a periphery, wherein the first number is equal to (three hundred and sixty degrees divided by the sum of a first conductive element angular width and a first separation angular width).

29. The hybrid plasma processing system as claimed in claim 28, wherein said second pattern comprises a second number of second conductive elements radially arranged around a center element, each second conductive element being substantially pie-shaped and extending from a center element to a periphery, wherein the second number is equal to (three hundred and sixty degrees divided by the sum of a second conductive element angular width and a second separation angular width).

30. The hybrid plasma processing system as claimed in claim 29, wherein said offset is equal to the first conductive element angular width.

31. The hybrid plasma processing system as claimed in claim 2, wherein said RF antenna comprises a plurality of major branches coupled and a plurality of minor branches coupled to said plurality of major branches, wherein each major branch has one end coupled to said first matching unit and a second end coupled to at least one minor branch.

32. The hybrid plasma processing system as claimed in claim 31, wherein said plurality of major branches extend radially from a center element and said center element is coupled to said first matching unit.

33. The hybrid plasma processing system as claimed in claim 32, wherein said Faraday shield further comprising a spiral pattern having a number of turns.

34. The hybrid plasma processing system as claimed in claim 33, wherein said Faraday shield further comprising a gas pipe connector and at least one gas dispensing orifice.

35. The hybrid plasma processing system as claimed in claim 2, wherein said RF antenna comprises at least one element having a zigzag form, and said Faraday shield comprises at least one conductive element having a complimentary zigzag form, so that the local directions of said RF antenna elements and said Faraday conductive elements are substantially perpendicular to each other.

36. The hybrid plasma processing system as claimed in claim 2, wherein said Faraday shield further comprises at least one cooling channel for circulating coolant.

37. The hybrid plasma processing system as claimed in claim 1, further comprising at least one controller adapted to control the operation of said CCP source, said ICP source, said gas supply system, and said exhaust system.

38. A hybrid plasma processing system for subjecting a target object to a plasma process, said system comprising:

process chamber formed in a process vessel;
gas supply system for supplying a process gas to said process chamber;
exhaust system for exhausting and controlling pressure in said process chamber;
susceptor arranged in said process chamber, said susceptor having a work surface for supporting said target object in said process chamber; and
hybrid plasma source for establishing a plasma and for biasing said plasma during said plasma process, said hybrid source comprising at least one ICP source antenna, at least one CCP source electrode, and Faraday shield, wherein said Faraday shield comprises a plurality of conductive elements, said Faraday shield providing at least one second electrode of said CCP source and providing at least one shield of said ICP source.

39. A hybrid plasma processing system for subjecting a target object to a plasma process, said system comprising:

process chamber formed in a process vessel;
a gas dispenser coupled to said process vessel, wherein said gas dispenser supplies a process gas to said process chamber;
exhaust system for exhausting and controlling pressure in said process chamber;
electrode arranged in said process chamber, said electrode having a work surface for supporting said target object in said process chamber;
RF antenna coupled to said process chamber for establishing a plasma during said plasma process; and
dual Faraday shield coupled to said RF antenna, and said process chamber, said dual Faraday shield comprising a first Faraday shield layer and a second Faraday shield layer, said Faraday shield providing a second electrode of a CCP source and providing at least one shield of an ICP source.

40. In a plasma processing system for subjecting a target object to a plasma process, the improvement comprising:

a hybrid plasma source comprising at least one inductively coupled plasma (ICP) source, at least one capacitively coupled plasma (CCP) source, and Faraday shield coupled to said ICP source and said CCP source, said hybrid source for establishing a plasma and for biasing said plasma during said plasma process, wherein said Faraday shield comprises a plurality of conductive elements, said Faraday shield providing at least one electrode in said CCP source and providing at least one shield in said ICP source.
Patent History
Publication number: 20040194890
Type: Application
Filed: Feb 25, 2004
Publication Date: Oct 7, 2004
Applicant: TOKYO ELECTRON LIMITED (Tokyo)
Inventor: Paul Moroz (Marblehead, MA)
Application Number: 10487730
Classifications
Current U.S. Class: With Radio Frequency (rf) Antenna Or Inductive Coil Gas Energizing Means (156/345.48)
International Classification: C23F001/00;