APPARATUS FOR TREATING A WAFER-SHAPED ARTICLE
An apparatus for processing wafer-shaped articles comprises a closed process chamber, a chuck located within the closed process chamber, and at least one process liquid dispensing device disposed within the chamber. The closed process chamber comprises a lid that can be opened to position a wafer-shaped article within the closed process chamber. The lid incorporates a heater adapted to heat a wafer-shaped article positioned in the closed process chamber.
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1. Field of the Invention
The invention relates generally to an apparatus for treating a wafer-shaped article, such as a semiconductor wafer.
2. Description of Related Art
Semiconductor wafers are subjected to various surface treatment processes such as etching, cleaning, polishing and material deposition. To accommodate such processes, a single wafer may be supported in relation to one or more treatment fluid nozzles by a chuck associated with a rotatable carrier, as is described for example in U.S. Pat. Nos. 4,903,717 and 5,513,668.
Such spin chucks may be accommodated in closed process chambers, as described for example in commonly-owned co-pending U.S. patent application Ser. No. 12/913,405, filed Oct. 27, 2010. Certain cleaning processes utilize aggressive liquid chemicals at elevated temperatures, as described for example in commonly-owned co-pending U.S. patent application Ser. No. 12/959,924, filed Dec. 3, 2010.
However, when a high temperature process is performed in an environmentally controlled process chamber, it can be difficult to maintain the desired temperature of the process liquid across the surface of the wafer, especially for wafers of relatively larger diameter, such as 300 mm and above.
SUMMARY OF THE INVENTIONAn apparatus for processing wafer-shaped articles according to the present invention comprises a closed process chamber, a chuck located within the closed process chamber, and at least one process liquid dispensing device disposed within the chamber. The closed process chamber comprises a lid that can be opened to position a wafer-shaped article within the closed process chamber. The lid comprises a heater adapted to heat a wafer-shaped article positioned in the closed process chamber.
In preferred embodiments of the apparatus according to the present invention, the heater comprises a plurality of infrared heating elements.
In preferred embodiments of the apparatus according to the present invention, the infrared heating elements are individually tuneable to apply a desired heating profile to a surface of a wafer-shaped article positioned within the closed process chamber.
In preferred embodiments of the apparatus according to the present invention, the lid is axially displaceable relative to a remaining structure of the closed process chamber while sealingly engaged with the remaining structure, so as to vary a distance between the heater and a wafer-shaped article positioned within the closed process chamber.
In preferred embodiments of the apparatus according to the present invention, the heater comprises one or a plurality of infrared heating elements, and the lid comprises a downwardly-facing peripheral shield that is essentially opaque to IR radiation.
In preferred embodiments of the apparatus according to the present invention, the lid comprises an internal gas inlet communicating with one or more internal peripheral recesses surrounding the heater, to permit a cooling gas to be supplied adjacent a periphery of the heater.
In preferred embodiments of the apparatus according to the present invention, the internal gas inlet is disposed in a central region of the lid, and is connected to the one or more internal peripheral recesses by a plurality of radially extending channels.
In preferred embodiments of the apparatus according to the present invention, the heater comprises one or a plurality of infrared heating elements, and the lid comprises an internal IR shield separating the one or a plurality of infrared heating elements from the one or more internal peripheral recesses.
In preferred embodiments of the apparatus according to the present invention, the heater is sealed within the lid so as to be protected from contact with process liquids inside the closed process chamber.
In preferred embodiments of the apparatus according to the present invention, the lid comprises at least one gas nozzle opening on or extending beyond a downwardly facing surface of the lid, so as to supply gas into the closed process chamber.
In preferred embodiments of the apparatus according to the present invention, the apparatus includes a drive unit for the at least one process liquid dispensing device, the drive unit being drivingly connected to the at least one dispensing device to move the at least one dispensing device from a peripheral standby position to one or more active positions in which a dispensing end of the at least one dispensing device is moved radially inwardly of the chuck, the drive unit being mounted outside of the chamber.
In preferred embodiments of the apparatus according to the present invention, the chamber is a component of a process module for single wafer wet processing of semiconductor wafers.
In preferred embodiments of the apparatus according to the present invention, the chuck is a spin chuck having a drive shaft extending downwardly from the chamber.
In preferred embodiments of the apparatus according to the present invention, the at least one process liquid dispensing device is operable to dispense liquid into the chamber while the lid is in the closed position.
In preferred embodiments of the apparatus according to the present invention, the chuck is vertically movable relative to the closed process chamber, and is configured to have at least three stopping positions, these being an uppermost position for loading and unloading a wafer-shaped article from the chuck, and at least two lower positions within the chamber, each of the at least two lower positions corresponding to a distinct process level of the chamber.
In preferred embodiments of the apparatus according to the present invention, the apparatus includes a drive mechanism that moves the lid from the closed position to the open position, the drive mechanism being adapted to displace the lid both upwardly and laterally relative to the chamber.
In preferred embodiments of the apparatus according to the present invention, drive unit is a motor mounted on a side housing of the chamber, an output shaft of the motor passing into the side housing and driving a link that passes into the chamber and connects to the at least one liquid dispensing device.
In preferred embodiments of the apparatus according to the present invention, the at least one process liquid dispensing device is a media supply arm pivotably mounted within the chamber and movable from a peripheral standby position to one or more active positions in which a dispensing end of the media supply arm is moved radially inwardly of the chuck.
In preferred embodiments of the apparatus according to the present invention, the media supply arm has one end pivotally connected to a link that passes through a wall of the chamber and an opposite end provided with a dispensing nozzle.
In preferred embodiments of the apparatus according to the present invention, the lid is arranged parallel to a wafer-shaped article received on the chuck.
In preferred embodiments of the apparatus according to the present invention, the closed process chamber comprises a plurality of superposed process levels, each of the plurality of superposed process levels having a respective gas exhaust connected thereto, wherein the gas exhausts are individually controllable.
In preferred embodiments of the apparatus according to the present invention, the closed process chamber is mounted on an upper surface of a base plate, and the apparatus also includes a drive unit for the chuck mounted in a housing that depends from a lower surface of the base plate.
In preferred embodiments of the apparatus according to the present invention, the drive mechanism that moves the lid from the closed position to the open position is mounted on a lower surface of a base plate, and the closed process chamber is mounted on an upper surface of the base plate.
Other objects, features and advantages of the invention will become more apparent after reading the following detailed description of preferred embodiments of the invention, given with reference to the accompanying drawings, in which:
Referring to
Lid 100 is secured to lid arm 22, which moves the lid 100 from the closed position shown in
First and second drive units 52, 62 are provided for respective media supply arms to be described below, and lead to respective covers 54, 64 for the pivotal movement mechanisms for the media supply arms. Reference numeral 56 denotes a lead-in for the first media supply line.
The closed chamber module of this embodiment has three interior levels, each of which has an associated gas exhaust, with reference numerals 82, 84 and 86 in
Referring now to
Inside the chamber, spin chuck 70 is visible, which in this embodiment is a chuck of the double-sided type. Also visible are the second media supply arm 63 in its standby position, and upper, middle and lower levels 34, 35, 36.
In
Motor 27, which may for example be a pneumatic cylinder, drives link 19, which in turn drives hollow shaft 18 (see
A spin motor 72 spins the spin chuck 70, whereas motor 76 raises and lowers spin chuck 70 via slider 74. A lower chamber cover 31 accommodates the bellows of the spin chuck, as will be described below.
In
The axial cross-section of
Lid 100 is depicted in greater detail in
As shown in
The IR-heaters are preferably linear quartz rods. There is an isolative coating provided so that the IR-heaters primarily emit IR-light towards the wafer surface.
The chamber and the IR-heaters are separated by a transparent plate 135, e.g. made of heat resistant glass (borosilicate glass), or quartz. Surrounding transparent plate 135 is an annular peripheral shield 125, which is formed of stainless steel or another material that is essentially opaque to infrared radiation. Shield 125 thus serves to focus the IR radiation onto the wafer surface and prevents the surrounding parts (e.g. the chamber walls), which are often made from a plastic material, from being excessively heated.
The assembly of IR heaters 120 is sealed within the lid 100 so that process liquid inside the sealed chamber cannot make contact with the IR heaters 120. This can be important for example when the process liquid is flammable, for example in the case of hot isopropyl alcohol used during drying treatments.
Although the heating elements in this embodiment are linear tubes, the heating elements may alternatively be embodied as tunable spot type IR lamps or concentric annular heating elements.
As shown in
Lid 100 in this embodiment is also axially displaceable relative to lid arm 22, by virtue of its mounting thereto via a series of six rods 103 that are rigidly secured to lid 100 but whose enlarged heads 104 are captive within pockets formed in lid arm 22, and in which they may slide axially upwardly against the force of springs 105 that surround the rods 103 and that bear via their upper ends on lid arm 22 and via their lower arms on the outer cover 133 of lid 100. A suitable gear motor or the like (not shown) can thus vary the spacing between the lid 100 and lid arm 22, and thus the spacing between the set of IR heating elements 120 and the upper surface of a wafer positioned with the process chamber. This axial positioning thus permits further tuning of the heating profile to be applied to a wafer.
In the axial cross-section of
Turning now to
Non-rotating hollow shaft 90 surrounds rotating hollow shaft 71, which in turn surrounds non-rotating hollow shaft 78, these three shafts being coaxial with one another. Rotary shaft seal bearing 91 seals the coaxial shafts from the chamber ambient and supports the interconnected rotary hollow shaft 78 and chuck carrier 73, whereas bearing 92 connects the non-rotating upper ring 94 with the rotating shaft 71. Membrane cover 93 is fitted within lower chamber cover 31, and at its inner periphery seals against bellows 75, and at its outer periphery seals against the chamber bottom 37.
In
In referring to a service position for the media supply arms 53, 63, it will be understood that there can be more than one service position, or for that matter the arms may be in service as they move radially inwardly from the peripheral standby position. Therefore, the service position can refer to any position where the dispensing end of the media supply arm is positioned above a wafer supported on the chuck, and not merely the central innermost position. For instance the service position will move from centre towards the edge and back again during processing of the wafer.
Thus, when drive unit 62 is actuated, link 67 will be pivoted over a range of motion dictated by the operating cycle of the drive unit 62, and which corresponds to displacement of the media supply arm 63 from its standby position to its service position. The size of the cutout in the cylindrical chamber wall 30 is therefore sized to accommodate that range of pivotal motion.
Lead-in 66 connects to the second media line 61 inside the chamber. Lead-in 66 may for example be a fluid coupling that traverses the cylindrical wall 30 of the chamber in a sealed manner, connecting to inlet tubing at its end outside the chamber and to second media line 61 at its end inside the chamber.
Also visible in
It will be appreciated that first and second media supply arms 53 and 63 are equipped with essentially the same drive mechanisms in this embodiment, such that the description of the various components of one unit applies also to the other, although such description might not be repeated herein. Moreover, although the present embodiment of the invention is equipped with two media dispense arms, the number of such arms and their associated drive mechanisms could be only one, or, conversely, could be three or more.
In
The perspective view of
In use, the chamber will be opened to permit loading a wafer to be processed therein. This involves first actuating the motor 28, which is fixed by posts to the underside of base plate 15 and stationary relative thereto (see
Once the lid 100 has been raised to open the chamber, motor 27 is next actuated to drive link 19 in an arcuate range of motion about the axis of shaft 18. As link 19 is non-rotabably secured to shaft 18, this motion rotates shaft 18 and with it lid arm 22 and lid 100, such that the lid 100 is swung away from the opening defined by the upper annular chamber cover 32, to the position shown in
After the chamber has been opened as shown in
It will be noted that the diameter of the opening in the upper annular cover 32 must obviously be greater than the outer diameter of a wafer to be processed in the chamber, but is preferably not of substantially greater diameter. For example, in the case of a 300 mm silicon wafer, the opening in cover 32 preferably has a diameter of approximately 320 mm. In general, the diameter of the opening in the upper end of the chamber should not exceed the diameter of a wafer to be processed by more than 50%, preferably by not more than 20%, and still more preferably by not more than 10%.
Spin chuck 70 is adapted to hold a wafer of a predetermined diameter, in this case 300 mm. Spin chuck 70 includes a peripheral series of gripping pins, which prevent the wafer from sliding laterally during processing. When spin chuck 70 is implemented as a Bernoulli chuck, a nitrogen gas flow supplied through the chuck and passing radially outwardly beneath the wafer provides the subjacent support of the wafer. Alternatively, the gripping pins may be configured with radially inwardly-facing surfaces that hold the wafer in its working position relative to the chuck, e.g. by having a shape complementary to the peripheral edge of the wafer, thereby providing both lateral and subjacent support.
Spin chuck 70 is then lowered by motor 76 to a working position at one of the upper, middle and lower levels 34, 35, 36, whereafter spin motor 72 commences to spin the spin chuck 70. Any desired combination of liquids and gases can then be supplied to the chamber interior, the liquids via media supply arms 53, 63 and the gases via lid 100.
It is preferred that one or more of the seals that seal the chamber be designed so as to permit controlled leakage of gas exteriorly of the chamber at a predetermined level of overpressure. In that way, a substantially oxygen-free atmosphere can be maintained within the chamber during processing of a wafer, while continuing to supply gas from lid 100 and/or through the shaft 78 without accumulation of excess pressure. This design also permits exclusion of oxygen without the need to rely upon the use of vacuum or the maintenance of completely impervious seals.
It will be appreciated that the design of this embodiment permits the lid and the media supply arms to supply gas and liquid simultaneously to the chamber interior. Furthermore, the design of the media supply arms 53, 63 and their associated drive mechanisms permits the arms to be disposed inside the chamber whereas their respective drive units are mounted outside the chamber. This provides the considerable advantage of preventing exposure of those drive units to the very aggressive chemicals often used in such processing modules.
While the present invention has been described in connection with various illustrative embodiments thereof, it is to be understood that those embodiments should not be used as a pretext to limit the scope of protection conferred by the true scope and spirit of the appended claims.
Claims
1. Apparatus for processing wafer-shaped articles, comprising a closed process chamber, a chuck located within said closed process chamber, and at least one process liquid dispensing device disposed within said chamber, said closed process chamber comprising a lid that can be opened to position a wafer-shaped article within said closed process chamber, said lid comprising a heater adapted to heat a wafer-shaped article positioned in the closed process chamber.
2. The apparatus according to claim 1, wherein said heater comprises a plurality of infrared heating elements.
3. The apparatus according to claim 2, wherein the infrared heating elements are individually tuneable to apply a desired heating profile to a surface of a wafer-shaped article positioned within said closed process chamber.
4. The apparatus according to claim 1, wherein said lid is axially displaceable relative to a remaining structure of said closed process chamber while sealingly engaged with said remaining structure, so as to vary a distance between said heater and a wafer-shaped article positioned within said closed process chamber.
5. The apparatus according to claim 1, wherein said heater comprises one or a plurality of infrared heating elements, and wherein said lid comprises a downwardly-facing peripheral shield that is essentially opaque to IR radiation.
6. The apparatus according to claim 1, wherein said lid comprises an internal gas inlet communicating with one or more internal peripheral recesses surrounding the heater, to permit a cooling gas to be supplied adjacent a periphery of said heater.
7. The apparatus according to claim 6, wherein said internal gas inlet is disposed in a central region of said lid, and is connected to said one or more internal peripheral recesses by a plurality of radially extending channels.
8. The apparatus according to claim 6, wherein said heater comprises one or a plurality of infrared heating elements, and wherein said lid comprises an internal IR shield separating said one or a plurality of infrared heating elements from said one or more internal peripheral recesses.
9. The apparatus according to claim 1, wherein said heater is sealed with said lid so as to be protected from contact with process liquids inside said closed process chamber.
10. The apparatus according to claim 1, wherein said lid comprises at least one gas nozzle opening on or extending beyond a downwardly facing surface of said lid, so as to supply gas into said closed process chamber.
11. The apparatus according to claim 1, further comprising a drive unit for the at least one process liquid dispensing device, the drive unit being drivingly connected to the at least one dispensing device to move the at least one dispensing device from a peripheral standby position to one or more active positions in which a dispensing end of the at least one dispensing device is moved radially inwardly of the chuck, said drive unit being mounted outside of said chamber.
12. The apparatus according to claim 1, wherein the chamber is a component of a process module for single wafer wet processing of semiconductor wafers.
13. The apparatus according to claim 1, wherein the chuck is a spin chuck having a drive shaft extending downwardly from the chamber.
14. The apparatus according to claim 1, wherein said at least one process liquid dispensing device is operable to dispense liquid into the chamber while said lid is in the closed position.
15. The apparatus according to claim 1, wherein said chuck is vertically movable relative to said closed process chamber, and is configured to have at least three stopping positions, these being an uppermost position for loading and unloading a wafer-shaped article from the chuck, and at least two lower positions within the chamber, each of said at least two lower positions corresponding to a distinct process level of said chamber.
Type: Application
Filed: Jul 7, 2011
Publication Date: Jan 10, 2013
Applicant: LAM RESEARCH AG (VILLACH)
Inventor: Karl-Heinz HOHENWARTER (DELLACH/GAIL)
Application Number: 13/178,430
International Classification: C23F 1/08 (20060101);