PLASMA PROCESSING APPARATUS AND PLASMA PROCESSING METHOD
A plasma processing apparatus 11 includes a reactant gas supply unit 13 for supplying a reactant gas for a plasma process into a processing chamber 12. The reactant gas supply unit 13 includes a first reactant gas supply unit 61 provided at a center of a dielectric plate 16 and configured to supply the reactant gas in a directly downward direction toward a central region of a processing target substrate W held on a holding table 14; and a second reactant gas supply unit 62 provided at a position directly above the holding table 14 but not directly above the processing target substrate W held on the holding table 14 and configured to supply the reactant gas toward a center of the processing target substrate W held on the holding table 14.
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The present invention relates to a plasma processing apparatus and a plasma processing method; and, more particularly, to a plasma processing apparatus and a plasma processing method for generating plasma by using a microwave as a plasma source.
BACKGROUND ARTA semiconductor device such as a LSI (Large Scale Integrated circuit) is manufactured by performing various processes such as etching, CVD (Chemical Vapor Deposition), sputtering or the like on a semiconductor substrate (wafer) as a processing target substrate. A processing method using plasma as an energy source, i.e., plasma etching, plasma CVD or plasma sputtering may be used to perform the etching, the CVD or the sputtering process. There are known various kinds of plasma such as parallel plate type plasma, ICP (Inductively-Coupled Plasma) and ECR (Electron Cyclotron Resonance) Plasma, and plasma generated by various apparatuses is used for a plasma process.
When the plasma etching or the like is performed on the processing target substrate, a reactant gas for processing the processing target substrate needs to be supplied into a processing chamber for generating plasma therein. Here, a technology for supplying the reactant gas into the processing chamber during the plasma process of the processing target substrate is described in Japanese Patent Laid-open Publication No. 2004-165374 (Patent Document 1) or Japanese Patent Laid-open Publication No. H6-112163 (Patent Document 2). In the Patent Document 1, an annular gas ring is provided between a mounting table for mounting thereon a processing target object and a main coil in a plasma processing apparatus using ECR plasma. The gas ring has a diameter larger than that of the mounting table. The reactant gas is supplied by the gas ring. In the Patent Document 2, a gas inlet for a deposition gas is provided in the vicinity of a sample holding table in a plasma processing apparatus using ECR plasma.
Patent Document 1: Japanese Patent Laid-open Publication No. 2004-165374
Patent Document 2: Japanese Patent Laid-open Publication No. H6-112163
DISCLOSURE OF THE INVENTION[Problems to Be Solved by the Invention]
When processing a processing target substrate, it may be desirable to process the processing target substrate uniformly over the entire surface thereof. When a reactant gas is supplied into the processing chamber, the reactant gas may be supplied from a multiple number of places in order to improve uniformity of the plasma process within the surface of the processing target object.
In the plasma processing apparatus 101 in which the two reactant gas supply units are provided at the two different positions as described above, when the reactant gas is supplied into the processing chamber 102 at a pressure range (equal to or larger than about 50 mTorr) of a viscous flow, the reactant gas supplied from the second reactant gas supply unit 106 is affected by the first reactant gas supply unit 104 and flows toward the central portion, as indicated by an arrow X of
Meanwhile, at a pressure range (equal to or less than about 50 mTorr) of a molecular flow, the reactant gas supplied from the second reactant gas supply unit 106 flows in a downward direction, as indicated by an arrow Y of
As stated above, in the plasma processing apparatus 101 having the above-described configuration, even if a supply amount of the gas from the second reactant gas supply unit 106 is adjusted by varying an internal pressure of the processing chamber 102, the reactant gas may not be uniformly supplied to the processing target substrate W. Thus, it may be difficult to achieve uniformity of the plasma process within the surface of the processing target substrate W. In the plasma processing apparatuses described in Patent Document 1 and Patent Document 2, the above-mentioned problem may be encountered.
Here, in case that the second reactant gas supply unit is provided in a position directly above the processing target substrate W so as to supply the reactant gas to the processing target substrate W uniformly, the following problems may be caused.
In this configuration, however, the reactant gas supplied from the first reactant gas supply unit 113 and the reactant gas supplied from the second reactant gas supply unit 115 may collide with each other in a region 116 between the central region and the edge region of the processing target substrate W in a diametric direction. In
Further, as shown in
Due to the stay of the deposit and the presence of the plasma shield as mentioned above, an etching rate of the processing target substrate W in the region 116 and an etching rate of the processing target substrate W in the central region or the edge region become different, resulting in deterioration of uniformity of the plasma process within the surface of the processing target substrate W.
The present invention provides a plasma processing apparatus capable of improving uniformity of a plasma process within a surface of a processing target substrate.
The present invention also provides a plasma processing method capable of improving uniformity of a plasma process within a surface of a processing target substrate.
[Means for Solving the Problems]
In accordance with one aspect of the present invention, there is provided a plasma processing apparatus including a processing chamber configured to perform therein a plasma process on a processing target substrate; a holding table provided within the processing chamber and configured to hold the processing target substrate thereon; a plasma generating unit configured to generate plasma within the processing chamber; and a reactant gas supply unit configured to supply a reactant gas for the plasma process into the processing chamber. The reactant gas supply unit includes a first reactant gas supply unit configured to supply the reactant gas in a directly downward direction toward a central region of the processing target substrate held on the holding table; and a second reactant gas supply unit provided at a position directly above the holding table but not directly above the processing target substrate held on the holding table, and configured to supply the reactant gas toward a center of the processing target substrate held on the holding table.
In accordance with this plasma processing apparatus, the reactant gas can be uniformly supplied to the entire processing target substrate by both the first reactant gas supply unit configured to supply the reactant gas in the directly downward direction toward the central region of the processing target substrate W and the second reactant gas supply unit configured to supply the reactant gas toward the center of the processing target substrate. Further, since the reactant gases supplied from the first and second reactant gas supply units do not stay on the processing target substrate, stay of deposits (reaction products) can be suppressed. Furthermore, the second reactant gas supply unit does not block a flow of plasma toward the processing target substrate. Accordingly, uniformity of the plasma process within the surface of the processing target substrate can be improved. Further, the “the position directly above the processing target substrate” refers to a vertically upper region of the processing target substrate, and the “the center of the processing target substrate” refers to the central region of the processing target substrate and a vertically upper region of the central region of the processing target substrate.
Desirably, the second reactant gas supply unit may be provided in the vicinity of the holding table.
More desirably, the second reactant gas supply unit may be configured to supply the reactant gas in an inclined direction toward a central region of the processing target substrate held on the holding table.
Further, the second reactant gas supply unit may be configured to supply the reactant gas in a horizontal direction toward the center of the processing target substrate held on the holding table.
More desirably, the second reactant gas supply unit may include a ring-shaped member, and the ring-shaped member may be provided with a supply hole through which the reactant gas is supplied.
More desirably, the processing target substrate may be of a circular plate shape, the ring-shaped member may be of a circular ring shape, and an inner diameter of the ring-shaped member may be larger than an outer diameter of the processing target substrate.
Moreover, the processing chamber may include a bottom positioned under the holding table and a sidewall upwardly extending from a periphery of the bottom, and the second reactant gas supply unit may be embedded within the sidewall.
More desirably, the sidewall may include an inwardly projecting protrusion, and the second reactant gas supply unit may be embedded within the protrusion.
Further, in a desirable embodiment, the plasma generating unit may include a microwave generator capable of generating a microwave for exciting plasma and a dielectric plate positioned to face the holding table and configured to introduce the microwave into the processing chamber, and the first reactant gas supply unit may be provided at a central portion of the dielectric plate.
More desirably, the plasma processing apparatus may further include a first temperature controller configured to control a temperature of the central region of the processing target substrate held on the holding table; and a second temperature controller configured to control a temperature of an edge region of the processing target substrate held on the holding table.
More desirably, at least one of the first and second temperature controllers may be divided into a plurality of members.
Further, in a desirable embodiment, the first and second temperature controllers may be provided within the holding table.
More desirably, the processing chamber may include a bottom positioned under the holding table and a sidewall upwardly extending from a periphery of the bottom, and the plasma processing apparatus may further include a sidewall temperature controller configured to control a temperature of the sidewall.
More desirably, the sidewall temperature controller may be provided within the sidewall.
In accordance with another aspect of the present invention, there is provided a plasma processing method for performing a plasma process on a processing target substrate. The plasma processing method includes holding the processing target substrate on a holding table provided within the processing chamber; generating a microwave for exciting plasma; introducing the microwave into the processing chamber through a dielectric plate; and supplying a reactant gas in a directly downward direction from a central portion of the dielectric plate toward a central region of the processing target substrate, and supplying the reactant gas in an inclined direction toward the processing target substrate from a position directly above the holding table but not directly above the processing target substrate held on the holding table.
In accordance with still another aspect of the present invention, there is provided a plasma processing apparatus including a holding table configured to hold a processing target substrate thereon; a processing chamber configured to perform therein a plasma process on the processing target substrate, and having a bottom positioned under the holding table and a ring-shaped sidewall upwardly extending from a periphery of the bottom; a plasma generating unit configured to generate plasma within the processing chamber; and a reactant gas supply unit configured to supply a reactant gas for the plasma process into the processing chamber. The reactant gas supply unit includes a first reactant gas supply unit configured to supply the reactant gas in a directly downward direction toward a central region of the processing target substrate held on the holding table; and a second reactant gas supply unit having a ring-shaped member provided at an upper position of the holding table and at a position deviated from a vertically upper region of the processing target substrate held on the holding table and at an inside position of the sidewall, and configured to supply the reactant gas toward a center of the processing target substrate held on the holding table.
Desirably, the ring-shaped member may be provided at an outside position of the holding table.
More desirably, the plasma processing apparatus may include a first temperature controller configured to control a temperature of the central region of the processing target substrate held on the holding table; and a second temperature controller configured to control a temperature of an edge region of the processing target substrate held on the holding table.
More desirably, the first and second temperature controllers may be provided within the holding table.
More desirably, at least one of the first and second temperature controllers may be divided into a plurality of members.
[Effect of the Invention]
In accordance with the plasma processing apparatus and the plasma processing method of the present invention, the reactant gas can be uniformly supplied to the entire processing target substrate by both the first reactant gas supply unit for supplying the reactant gas in the directly downward direction toward the processing target substrate and the second reactant gas supply unit for supplying the reactant gas toward the processing target substrate in the inclined direction. Further, since the reactant gases supplied from the first and second reactant gas supply units do not stay on the processing target substrate, stay of deposits (reaction products) can be suppressed. Furthermore, the second reactant gas supply unit does not block a flow of plasma toward the processing target substrate. Accordingly, uniformity of the plasma process within the surface of the processing target substrate can be improved.
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
The processing chamber 12 may include a bottom 17 positioned under the holding table 14 and a sidewall 18 extending upward from the periphery of the bottom 17. The sidewall 18 has a cylindrical shape. A gas exhaust hole 19 for gas exhaust is provided in the bottom 17 of the processing chamber 12. A top of the processing chamber 12 is opened and the processing chamber 12 can be hermetically sealed by a dielectric plate 16 provided at the top of the processing chamber 12 and by an O-ring 20 as a sealing member provided between the dielectric plate 16 and the processing chamber 12.
The microwave generator 15 having a matching unit 21 is connected to an upper portion of a coaxial waveguide 24 for introducing a microwave via a mode converter 22 and a waveguide 23. For example, a microwave of a TE mode generated by the microwave generator 15 is converted to a TEM mode by the mode converter 22 after it passes through the waveguide 23. Then, the microwave of the TEM mode propagates through the coaxial waveguide 24. The coaxial waveguide 24 may include a central conductor 25 provided at a center thereof in a diametric direction; and an external conductor 26 provided at the outside of the central conductor 25 in the diametric direction. An upper end of the central conductor 25 is connected to a ceiling partition wall of the mode converter 22. A frequency of the microwave generated by the microwave generator 15 is, for example, about 2.45 GHz. Further, the waveguide 23 may have a circular or a rectangular cross section.
The dielectric plate 16 is of a circular plate shape and is made of a dielectric material. A ring-shaped tapered recess 27 is provided on a bottom surface of the dielectric plate 16 to facilitate generation of a standing wave by the introduced microwave. Due to the recess 27, plasma can be efficiently generated under the dielectric plate 16 by the microwave. Further, the dielectric plate 16 may be made of a material such as, but not limited to, quartz or alumina.
Further, the plasma processing apparatus 11 may include a wavelength shortening plate 28 for propagating the microwave introduced through the coaxial waveguide 24; and a thin circular slot plate 30 for introducing the microwave to the dielectric plate 16 through a multiple number of slot holes 29. The microwave generated by the microwave generator 15 is propagated to the wavelength shortening plate 28 through the coaxial waveguide 24 and is then introduced to the dielectric plate 16 through the slot holes 29 provided in the slot plate 30. The microwave transmitted through the dielectric plate 16 generates an electric field directly under the dielectric plate 16. As a result, plasma is generated within the processing chamber 12.
The holding table 14 also serves as a high frequency electrode and is supported by a cylindrical insulating support 31 extending vertically upward from the bottom 17. A ring-shaped gas exhaust passageway 33 is formed between the sidewall 18 of the processing chamber 12 and a cylindrical conductive support 32 extending vertically upward from the bottom 17 along the outer periphery of the cylindrical support 31. A ring-shaped baffle plate 34 provided with a multiple number of through holes is fixed to an upper portion of the gas exhaust passageway 33. A gas exhaust unit 36 is connected to a bottom portion of the gas exhaust hole 19 via a gas exhaust pipe 35. The gas exhaust unit 36 has a vacuum pump such as a turbo molecular pump. The inside of the processing chamber 12 can be depressurized to a desired vacuum level by the gas exhaust unit 36.
The holding table 14 is electrically connected with a high frequency RF bias power supply 37 via a matching unit 38 and a power supply rod 39. The high frequency power supply 37 outputs a high frequency power of a certain frequency, e.g., about 13.56 MHz, suitable for controlling energy of ions attracted into the processing target substrate W. The matching unit 38 has a matcher for matching impedance on the side of the high frequency power supply 37 with impedance on the side of a load such as an electrode, plasma and the processing chamber 12. A blocking capacitor for generation of self-bias is included in the matcher.
An electrostatic chuck 41 configured to hold the processing target substrate W by an electrostatic attracting force is provided on a top surface of the holding table 14. Further, a focus ring 42 is provided at a periphery of the electrostatic chuck 41 in a diametric direction to surround the processing target substrate W in a ring shape. The electrostatic chuck 41 may include an electrode 43 made of a conductive film sandwiched between a pair of insulating films 44 and 45. The electrode 43 is electrically connected with a high voltage DC power supply 46 via a switch 47 and a coated line 48. The processing target substrate W can be attracted to and held on the electrostatic chuck 41 by a Coulomb force generated by a DC voltage applied from the DC power supply 46.
A ring-shaped coolant path 51 extending in a circumferential direction of the holding table 14 is provided within the holding table 14. A coolant of a preset temperature, e.g., cooling water is supplied into and circulated through the coolant path 51 from a chiller unit (not shown) via pipes 52 and 53. A processing temperature of the processing target substrate W on the electrostatic chuck 41 can be controlled by adjusting the temperature of the coolant. Further, a heat transfer gas from a heat transfer gas supply unit (not shown), e.g., a He gas is supplied to between a top surface of the electrostatic chuck 41 and a rear surface of the processing target substrate W via a gas supply pipe 54.
Now, a detailed configuration of the reactant gas supply unit 13 for supplying a reactant gas for the plasma process into the processing chamber 12 will be explained. The reactant gas supply unit 13 may include a first reactant gas supply unit 61 for supplying the reactant gas in a directly downward direction toward the central region of the processing target substrate W; and a second reactant gas supply unit 62 for supplying the reactant gas toward the processing target substrate W in an inclined direction. To elaborate, the first reactant gas supply unit 61 supplies the reactant gas in a direction indicated by an arrow F1 of
A configuration of the first reactant gas supply unit 62 will be first elaborated. The first reactant gas supply unit 61 is provided at a center of the dielectric plate 16 in a diametric direction and is located at an upper position of the dielectric plate 16 from a bottom surface 63 of the dielectric plate 16 facing the holding table 14. The dielectric plate 16 is provided with an accommodation part 64 for accommodating the first reactant gas supply unit 61 therein. An O-ring 65 is provided between the first reactant gas supply unit 61 and the accommodation part 64 so as to secure airtightness of the inside of the processing chamber 112.
The first reactant gas supply unit 61 is provided with a multiple number of supply holes 66 through which the reactant gas is discharged in a directly downward direction toward the central region of the processing target substrate W. The supply holes 66 are provided in an area of the wall surface 67 facing the holding table 14 and the area is exposed to the inside of the processing chamber 12. Further, the wall surface 67 is flat. The supply holes 66 are provided in the first reactant gas supply unit 61 to be located at the center of the dielectric plate 16 in the diametric direction.
The plasma processing apparatus 11 is provided with a gas flow path 68 formed through the central conductor 25 of the coaxial waveguide 24, the slot plate 30 and the dielectric plate 16 to reach the supply holes 66. A gas supply system 72 including an opening/closing valve 70 and/or a flow rate controller 71 such as a mass flow controller is connected to a gas inlet 69 formed at an upper end of the central conductor 25. The reactant gas is supplied while its flow rate is controlled by the gas supply system 72.
Now, a configuration of the second reactant gas supply unit 62 will be elaborated.
Now, the ring-shaped member 73 will be elaborated.
The ring-shaped member 73 is provided with a multiple number of supply holes 75 through which the reactant gas is discharged in an inclined direction toward the processing target substrate W. Each supply hole 75 has a circular shape. The supply holes 75 are provided in the wall 79d extending in the slant direction. To elaborate, each supply hole 75 is formed by opening a part of the wall 79d in a direction orthogonal to the wall 79d. An inclination angle of the supply hole 75 may be selected depending on the direction for supplying the reactant gas. Here, the inclination angle of the supply hole 75 is the same as an angle of the inclined direction for supplying the reactant gas by the second reactant gas supply unit 62 and is defined as an angle θ between a straight line (indicated by a dashed dotted line of
The holding member 74 is of a pipe shape. The reactant gas supplied from the outside of the processing chamber 12 reaches the ring-shaped member 73 through the inside of the holding member 74. The holding member 74 has a substantially L-shaped cross section and is inwardly protruded from an upper portion of the sidewall 18 and vertically extended in a downward direction. An end portion 76 of the holding member 74 extended in the downward direction is connected with the ring-shaped member 73. A gas supply system (not shown) including an opening/closing valve and a flow rate controller as mentioned above may also be installed outside the holding member 74.
In this embodiment, the second reactant gas supply unit 62 is located in a position directly above the holding table 14 but not located directly above the processing target substrate W held on the holding table 14. Specifically, if an inner diameter of the ring-shaped member 73 is denoted by D1 and an outer diameter of the processing target substrate W is denoted by D2, the inner diameter D1 of the ring-shaped member 73 is set to be larger than the outer diameter D2 of the processing target substrate W. Further, the holding member 74 is also located at a position which is not directly above the processing target substrate W.
Desirably, the second reactant gas supply unit 62 may be located at the vicinity of the holding table 14. Specifically, the ring-shaped member 73 may be provided in a so-called downflow region which is not affected by the reactant gas supplied from the first reactant gas supply unit 61 and in which a plasma density is low. A distance L1 from a top surface 77 of the processing target substrate W held on the holding table 14 to the center 78 of the ring-shaped member 73 indicated by the dashed dotted line of
Now, a method for performing a plasma process on a processing target substrate W by the plasma processing apparatus 11 in accordance with the embodiment of the present invention will be explained.
First, the processing target substrate W is held on the electrostatic chuck 41 of the holding table 14 installed in the processing chamber 12. Then, a microwave for exciting plasma is generated by the microwave generator 15, and, then, the microwave is introduced into the processing chamber 12 through the dielectric plate 16 or the like. Then, a reactant gas is supplied in a directly downward direction from a central portion of the dielectric plate 16 toward a central region of the processing target substrate W through the supply holes 66 of the first reactant gas supply unit 61. Further, the reactant gas is also supplied in an inclined direction toward the central region of the processing target substrate W through the supply holes 75 of the ring-shaped member 73 of the second reactant gas supply unit 62. In this way, a plasma process is performed on the processing target substrate W.
In accordance with the plasma processing apparatus 11 and the plasma processing method as described above, the reactant gas can be uniformly supplied to the entire processing target substrate W by the first reactant gas supply unit 61 that supplies the reactant gas in the directly downward direction toward the central region of the processing target substrate W and by the second reactant gas supply unit 62 that supplies the reactant gas in the inclined direction toward the central region of the processing target substrate W. Furthermore, since the reactant gases supplied by the first and second reactant gas supply units 61 and 62 do not stay on the processing target substrate W, stay of deposits on the processing target substrate W can be suppressed. Moreover, the second reactant gas supply unit 62 does not block a flow of plasma toward the processing target substrate W. Accordingly, uniformity of the plasma process within a surface of the processing target substrate W can be improved.
Here, flows of the reactant gases supplied from the first reactant gas supply unit 61 and the second reactant gas supply unit 62 of the plasma processing apparatus 11 having the above-described configuration will be elaborated.
As can be seen from
In the plasma processing apparatus 11 having the above-described configuration, the uniformity of the plasma process in the surface of the processing target substrate W can be improved by supplying the reactant gas from the second reactant gas supply unit 62 in the inclined direction. Meanwhile, in the conventional plasma processing apparatus as depicted in
Moreover, in the plasma processing apparatus in accordance with the embodiment of the present invention, since respective components of the second reactant gas supply unit 62 are provided at positions other than directly above the processing target substrate W, fatigue of each component of the second reactant gas supply unit 62 due to plasma can be reduced. Thus, lifetime of the second reactant gas supply unit 62 can be increased.
In addition, although the embodiment has been described for the case that the second reactant gas supply unit includes the ring-shaped member and the holding members for holding the ring-shaped member from a higher position of the sidewall than the ring-shaped member, the present invention may not be limited thereto. By way of example, the second reactant gas supply unit may include the ring-shaped member and supporting members straightly extended from the sidewall of the processing chamber inwardly in a diametric direction.
Moreover, although this embodiment has been described for the case that the second reactant gas supply unit includes the ring-shaped member and the holding members for holding the ring-shaped member from a higher position of the sidewall than the ring-shaped member, the present invention may not be limited thereto. By way of example, the second reactant gas supply unit for supplying the reactant gas in the inclined direction toward the processing target substrate W may be embedded in a sidewall of the processing chamber.
Furthermore, in the plasma processing apparatus, the sidewall of the processing chamber may include an inwardly projecting protrusion, and the second reactant gas supply unit may be embedded in the protrusion.
In such a case, the processing chamber 87 may have a bottle neck structure as an overall shape in which an inner diameter of the sidewall 82 above the ring-shaped member 84 is smaller than an inner diameter of the sidewall 82 below the ring-shaped member 84.
Furthermore, in the above-described embodiment, each supply hole of the ring-shaped member has a circular shape. However, the present invention may not be limited thereto, and the supply hole may have an elongated shape extending in a circumferential direction or in a diametric direction. Moreover, in the above-described embodiment, although the number of the supply holes is 8, the present invention may not be limited thereto.
Besides, in the above-described embodiment, the ring-shaped member includes a multiple number of walls respectively extending in the vertical direction, the left-right direction and the slant direction. However, the present invention may not be limited thereto, and the ring-shaped member may have, but not limited to, a curved wall portion. Further, in the cross sectional view of
Furthermore, in the above-described embodiment, the second reactant gas supply unit includes the ring-shaped member. However, the present invention may not be limited thereto, and the second reactant gas supply unit may not include the ring-shaped member. By way of example, supply holes may be provided in lower ends of a multiplicity of holding members, and the reactant gas may be supplied in an inclined direction toward the processing target substrate W through these supply holes.
Moreover, in the above-described embodiment, the second reactant gas supply unit supplies the reactant gas in the inclined direction toward the central region of the processing target substrate W held on the holding table. However, the present invention may not be limited thereto, and the second reactant gas supply unit may be configured to supply the reactant gas in a horizontal direction toward the center of the processing target substrate W held on the holding table. To be more specific, referring to
Such a case will be elaborated with reference to the accompanying drawings.
Referring to
The second reactant gas supply unit 202 may be formed by joining a flat ring-shaped first member 209a provided with protrusions corresponding to the protrusions 211a to 211c and a ring-shaped second member 209b having a substantially one-side-opened rectangular cross section and provided with protrusions corresponding to the protrusions 211a to 211c. As shown in
The second reactant gas supply unit 202 is provided with thirty six (36) supply holes 215 through which the reactant gas is supplied into a processing chamber 12. The supply holes 215 are formed so as to supply the reactant gas in a straightly diametric direction toward an inside of the ring-shaped member 208. To elaborate, each supply hole 215 is formed through an inner wall of the second member 209b of the second reactant gas supply unit 202. The supply holes 215 are formed at substantially midway positions of the ring-shaped member 208 in a vertical direction. Each supply hole 215 has a circular shape having a size of, e.g., about φ0.5 mm. The supply holes 215 are opened by, e.g., laser. The thirty six (36) supply holes 215 are arranged at a regular distance on an inner surface 216 of the second reactant gas supply unit 202 in a circumferential direction thereof.
The second reactant gas supply unit 202 is installed in the processing chamber 12 by being supported by three supports 212a, 212b and 212c provided at a sidewall 18 of the processing chamber 12. To elaborate, inner surfaces 214a, 214b and 214c of the three supports 212a, 212b and 212c inwardly extended from the sidewall 18 in a diametric direction at an interval of about 120° are joined to outer surfaces 213a, 213b and 213c of the three protrusions 211a, 211b and 211c of the second reactant gas supply unit 202, respectively. With regard to an installation position of the ring-shaped member 208 in a vertical direction, the ring-shaped member 208 is installed in a so-called downflow region.
Here, the support 212a has a hollow shape, and the gas can be supplied into the gas flow path 210 of the second reactant gas supply unit 202 through the support 212a from the outside of the processing chamber 12. Meanwhile, the other two supports 212b and 212c have solid shapes without allowing an inflow/outflow of the gas. That is, in the second reactant gas supply unit 202, the gas is introduced into the gas flow path 210 from the outside of the processing chamber 12 through the support 212a and the protrusion 211a and then is discharged into the processing chamber 12 toward a center of the processing target substrate W through the 36 supply holes 215.
Further, the plasma processing apparatus 201 illustrated in
Moreover, in the plasma processing apparatus 201 illustrated in
In accordance with the plasma processing apparatus 201 having the above-described configuration, the same effects as described above can also be achieved. That is, uniformity of the plasma process within the surface of the processing target substrate W can be obtained.
In accordance with sill another embodiment, since the ring-shaped member 208 of the second reactant gas supply unit 202 is configured as a separate member from the sidewall 18 or the cover 17 and is supported within the processing chamber 12 by the three supports 212a to 212c, the ring-shaped member 208 is kept away from the temperature controllers 206 and 207 and, thus, a temperature of the ring-shaped member 208 can be maintained stable. Accordingly, the ring-shaped member 208 may not be affected by the temperature control by the temperature controllers 206 and 207, and, thus, a gas supply amount through the supply holes 215 of the second reactant gas supply unit 202 can be stabilized.
Referring to
As can be seen from
Referring to
This result shows that the process non-uniformity can be changed from the edge-fast distribution to the center-fast distribution. On these graphs, it may be easy to adjust the process non-uniformity to about 0% by varying the center/edge flow rate ratio, i.e., by varying the gas supply amounts from the first and second reactant gas supply units. On the graph shown in
Further, in this embodiment, although each supply hole is described to have a circular shape, the present invention may not be limited thereto, and the supply hole may have, by way of example, an elongated shape, an oval shape or a polygonal shape. Furthermore, a vertical position for forming the supply holes may not be limited to the midway position, but the supply holes may be formed at an upper portion or a lower portion of the ring-shaped member 208 in a vertical direction. Moreover, an opening size of each supply hole may be varied as required, and the number of the supply holes is not limited to the mentioned example. By way of example, 8 or 16 supply holes may be provided. In addition, the cross section of the ring-shaped member may have a circular or polygonal cross section.
Moreover, although this embodiment has been described for the case that the second reactant gas supply unit includes the first and second members and supported by the three supports, the present invention may not be limited thereto, and the second reactant gas supply unit for discharging the gas in the horizontal direction may be embedded in a sidewall of the processing chamber, as in the plasma processing apparatus shown in
Referring to
A part of a sidewall 82 of a processing chamber 12 of the plasma processing apparatus 221 is projected inward in a diametric direction. This protrusion 229 is of a circular ring shape. Further, gas supply holes 231 are opened through an inner surface 228 of the protrusion 229 in a horizontal direction. Further, a gas flow path 230 extended from the outside of the processing chamber 12 to the supply holes 231 is provided within the sidewall 82. Each supply hole 231 is opened in a circular shape and the supply holes 231 are arranged at a regular distance in a circumferential direction. In addition, as in the plasma processing apparatus shown in
Moreover, in the above-described embodiments, although the second reactant gas supply unit of the plasma processing apparatus is located at a position directly above the holding table but not directly above the processing target substrate W, the present invention may not be limited thereto, and the plasma processing apparatus may be configured as follows.
That is, the plasma processing apparatus may include a holding table configured to hold the processing target substrate thereon; a processing chamber configured to perform therein a plasma process on the processing target substrate, and having a bottom positioned under the holding table and a ring-shaped sidewall upwardly extending from a periphery of the bottom; a plasma generator configured to generate plasma within the processing chamber; and a reactant gas supply unit configured to supply a reactant gas for the plasma process into the processing chamber. Further, the reactant gas supply unit may include a first reactant gas supply unit configured to supply the reactant gas in a directly downward direction toward a central region of the processing target substrate held on the holding table; and a second reactant gas supply unit having a ring-shaped member provided at an upper position of the holding table and at a position deviated from a direct region of the processing target substrate held on the holding table and at an inside position of the sidewall, and configured to supply the reactant gas toward a center side of the processing target substrate held on the holding table.
Further, in the plasma processing apparatuses shown in
In the above-described embodiments, although a wall surface of the first reactant gas supply unit facing the holding table is flat, the present invention may not be limited thereto, and a part of the first reactant gas supply unit in which the supply holes are provided may be protruded toward the holding table.
Further, in the above-described embodiments, although the same kind of reactant gas is supplied from the first and second reactant gas supply units, the kinds of gases from the first and second reactant gas supply unit may be different.
Moreover, the second reactant gas supply unit may be configured to supply the gas in a directly downward direction in consideration of an apparatus configuration, particularly, in consideration of dimensions of various components of the apparatus such as a size of the processing chamber, a position of the holding table, a size of the processing target substrate and so forth.
Furthermore, in the above-described embodiments, the plasma processing apparatus is of a type that uses a microwave as a plasma source, the present invention may not be limited thereto. By way of example, the present invention may also be applicable to a plasma processing apparatus using ICP (Inductively-Coupled Plasma), ECR (Electron Cyclotron Resonance) plasma, parallel plate type plasma or the like as a plasma source.
While various aspects and embodiments have been described herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for the purposes of illustration and are not intended to be limiting. Therefore, the true scope and spirit of the invention is indicated by the appended claims rather than by the foregoing description, and it shall be understood that all modifications and embodiments conceived from the meaning and scope of the claims and their equivalents are included in the scope of the invention.
INDUSTRIAL APPLICABILITYA plasma processing apparatus and a plasma processing method in accordance with the present invention may be effectively used to improve uniformity of a plasma process within a surface of a processing target substrate.
[Explanation of Codes]
11, 81, 91, 201, 221, 241: Plasma processing apparatus
12, 87: Processing chamber
13: Reactant gas supply unit
14: Holding table
15: Microwave generator
16: Dielectric plate
17: Bottom
18, 22: Sidewall
19: Gas exhaust hole
20, 65: O-ring
21: Matching unit
22: Mode converter
23: Waveguide
24: Coaxial waveguide
25: Central conductor
26: External conductor
27: Recess
28: Wavelength shortening plate
29: Slot hole
30: Slot plate
31,32: Cylindrical support
33: Gas exhaust passageway
34: Baffle plate
35: Gas exhaust pipe
36: Gas exhaust unit
37: High frequency power supply
38: Matching unit
39: Power supply rod
41: Electrostatic chuck
42: Focus ring
43: Electrode
44, 45: Insulating film
46: DC power supply
47: Switch
48: Coated line
51: Coolant path
52, 53: Pipe
54: Gas supply pipe
61: First reactant gas supply unit
62, 92, 202, 222, 242: Second reactant gas supply unit
63: Bottom surface
64: Accommodation part
66, 75, 85, 95, 215, 231: Supply hole
67, 86, 88: Wall surface
68, 89, 210, 230: Gas flow path
69: Gas inlet
70: Opening/closing valve
71: Flow rate controller
72: Gas supply system
73, 84, 93, 208: Ring-shaped member
74: Holding member
76: End portion
77: Top surface
78: Center
79a, 79b, 79c, 79d: Wall
79e: Straight line
80: Position
83, 229: Protrusion
94, 212a, 212b, 212c: Supporting member
203, 204, 205, 206, 207, 223, 224, 225, 226, 227:
Temperature control unit
209a: First member
209b: Second member
211a, 211b, 211c: Protrusion
213a, 213b, 213c: Outer surface
214a, 214b, 214c, 216, 228: Inner surface
217: Cover
Claims
1. A plasma processing apparatus comprising:
- a processing chamber configured to perform therein a plasma process on a processing target substrate;
- a holding table provided within the processing chamber and configured to hold the processing target substrate thereon;
- a plasma generating unit configured to generate plasma within the processing chamber; and
- a reactant gas supply unit configured to supply a reactant gas for the plasma process into the processing chamber,
- wherein the reactant gas supply unit comprises:
- a first reactant gas supply unit configured to supply the reactant gas in a directly downward direction toward a central region of the processing target substrate held on the holding table; and
- a second reactant gas supply unit provided at a position directly above the holding table but not directly above the processing target substrate held on the holding table, and configured to supply the reactant gas toward a center of the processing target substrate held on the holding table.
2. The plasma processing apparatus of claim 1, wherein the second reactant gas supply unit is provided in the vicinity of the holding table.
3. The plasma processing apparatus of claim 1, wherein the second reactant gas supply unit is configured to supply the reactant gas in an inclined direction toward a central region of the processing target substrate held on the holding table.
4. The plasma processing apparatus of claim 1, wherein the second reactant gas supply unit is configured to supply the reactant gas in a horizontal direction toward the center of the processing target substrate held on the holding table.
5. The plasma processing apparatus of claim 1, wherein the second reactant gas supply unit comprises a ring-shaped member, and
- the ring-shaped member is provided with a supply hole through which the reactant gas is supplied.
6. The plasma processing apparatus of claim 5, wherein the processing target substrate is of a circular plate shape,
- the ring-shaped member is of a circular ring shape, and
- an inner diameter of the ring-shaped member is larger than an outer diameter of the processing target substrate.
7. The plasma processing apparatus of claim 1, wherein the processing chamber comprises a bottom positioned under the holding table and a sidewall upwardly extending from a periphery of the bottom, and
- the second reactant gas supply unit is embedded within the sidewall.
8. The plasma processing apparatus of claim 7, wherein the sidewall comprises an inwardly projecting protrusion, and
- the second reactant gas supply unit is embedded within the protrusion.
9. The plasma processing apparatus of claim 1, wherein the plasma generating unit comprises a microwave generator capable of generating a microwave for exciting plasma and a dielectric plate positioned to face the holding table and configured to introduce the microwave into the processing chamber, and
- the first reactant gas supply unit is provided at a central portion of the dielectric plate.
10. The plasma processing apparatus of claim 1, further comprising:
- a first temperature controller configured to control a temperature of the central region of the processing target substrate held on the holding table; and
- a second temperature controller configured to control a temperature of an edge region of the processing target substrate held on the holding table.
11. The plasma processing apparatus of claim 10, wherein the first and second temperature controllers are provided within the holding table.
12. The plasma processing apparatus of claim 10, wherein at least one of the first and second temperature controllers is divided into a plurality of members.
13. The plasma processing apparatus of claim 1, wherein the processing chamber comprises a bottom positioned under the holding table and a sidewall upwardly extending from a periphery of the bottom, and
- the apparatus further comprises a sidewall temperature controller configured to control a temperature of the sidewall.
14. The plasma processing apparatus of claim 12 13, wherein the sidewall temperature controller is provided within the sidewall.
15. A plasma processing method for performing a plasma process on a processing target substrate, the method comprising:
- holding the processing target substrate on a holding table provided within the processing chamber;
- generating a microwave for exciting plasma;
- introducing the microwave into the processing chamber through a dielectric plate; and
- supplying a reactant gas in a directly downward direction from a central portion of the dielectric plate toward a central region of the processing target substrate, and supplying the reactant gas in an inclined direction toward the processing target substrate from a position directly above the holding table but not directly above the processing target substrate held on the holding table.
16. A plasma processing apparatus comprising:
- a holding table configured to hold a processing target substrate thereon;
- a processing chamber configured to perform therein a plasma process on the processing target substrate, and having a bottom positioned under the holding table and a ring-shaped sidewall upwardly extending from a periphery of the bottom;
- a plasma generating unit configured to generate plasma within the processing chamber; and
- a reactant gas supply unit configured to supply a reactant gas for the plasma process into the processing chamber,
- wherein the reactant gas supply unit comprises:
- a first reactant gas supply unit configured to supply the reactant gas in a directly downward direction toward a central region of the processing target substrate held on the holding table; and
- a second reactant gas supply unit having a ring-shaped member provided at an upper position of the holding table and at a position deviated from a vertically upper region of the processing target substrate held on the holding table and at an inside position of the sidewall, and configured to supply the reactant gas toward a center of the processing target substrate held on the holding table.
17. The plasma processing apparatus of claim 16, wherein the ring-shaped member is provided at an outside position of the holding table.
18. The plasma processing apparatus of claim 16, further comprising:
- a first temperature controller configured to control a temperature of the central region of the processing target substrate held on the holding table; and
- a second temperature controller configured to control a temperature of an edge region of the processing target substrate held on the holding table.
19. The plasma processing apparatus of claim 18, wherein the first and second temperature controllers are provided within the holding table.
20. The plasma processing apparatus of claim 18, wherein at least one of the first and second temperature controllers is divided into a plurality of members.
Type: Application
Filed: Aug 25, 2009
Publication Date: Oct 6, 2011
Applicant: TOKYO ELECTRON LIMITED (Minato-ku, Tokyo)
Inventors: Nobuyuki Okayama ( Hyogo), Naoki Matsumoto ( Hyogo)
Application Number: 13/129,607
International Classification: C23F 1/00 (20060101); C23F 1/08 (20060101);