DIFFUSER SUPPORT
Embodiments of gas distribution apparatus comprise a diffuser support member coupled to a diffuser and moveably disposed through a backing plate. Embodiments of methods of processing a substrate on a substrate receiving surface of a substrate support comprise providing a diffuser in which a diffuser support member supports the diffuser and is moveably disposed through the backing plate.
1. Field of the Invention
Embodiments of the present invention generally relate to apparatus and methods for supporting a gas distribution plate or diffuser.
2. Description of the Related Art
Substrates in which flat panel displays are made from have increased dramatically in size over recent years. For example, a substrate which is typically divided to make a plurality of TFT-LCD flat panel displays had sizes of about 2,000 cm2 and have increased in size to about 25,000 cm2 or larger. Such substrates are typically processed in a plasma chamber having a diffuser. The diffuser is generally supported in a spaced-apart relation facing the substrate with a plurality of gas passageways adapted to disperse one or more process gases toward the substrate to perform a process to the substrate, such as deposition or etch. This increase in substrate size has brought an increase in diffuser size since the diffuser is approximately the size of the substrate.
Problems with current diffusers include sagging, creeping, movement, and/or cracking of the diffuser or associated components over time, due to exposure of the diffuser to high processing temperatures, to the forces of gravity, and to other forces. Such problems with current diffuser designs may adversely affect substrate processing uniformity and properties and may increase maintenance and replacement costs of the diffuser and associated components.
Therefore, there is a need for an improved gas distribution apparatus and methods.
SUMMARY OF THE INVENTIONEmbodiments of gas distribution apparatus comprise a diffuser support member coupled to a diffuser and moveably disposed through a backing plate. Certain embodiments of gas distribution apparatus further comprise a chamber body including a bottom and walls. The backing plate is disposed over the chamber body. A chamber interior volume is bounded by the chamber body and the backing plate. The diffuser is disposed within the chamber interior volume. Other embodiments of gas distribution apparatus further comprise variable spacing between the backing plate and the diffuser.
Embodiments of methods of processing a substrate on a substrate receiving surface of a substrate support comprise providing a diffuser within a chamber interior volume bounded by a chamber body and a backing plate. A diffuser support member supports the diffuser and is moveably disposed through the backing plate. In certain embodiments, a vacuum pressure is applied within the chamber interior volume in which the backing plate flexes in response to the vacuum pressure. In other embodiments, the diffuser support member is coupled to a structure outside of the chamber interior volume.
So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one embodiment may be beneficially utilized on other embodiments without specific recitation.
DETAILED DESCRIPTIONEmbodiments of the present invention generally provide apparatus and methods for supporting a diffuser in a processing apparatus adapted to process the substrate, such as in a deposition, etch, plasma treatment, plasma clean, or other substrate process.
The chamber 100 comprises a chamber body having walls 102 and a bottom 104. The chamber 100 also includes a backing plate 112 coupled to the lid 123 of the chamber 100. A chamber interior volume 106 is bounded by the chamber body and the backing plate 112. A substrate support 130 is disposed within the chamber interior volume 106. The chamber interior volume 106 is accessed through a sealable slit valve 108 so that a substrate 140 may be transferred in and out of the chamber 100. The substrate support 130 includes a substrate receiving surface 132 for supporting the substrate 140 and includes a stem 134 coupled to a lift system 136 to raise and lower the substrate support 130. A shadow ring (not shown) may be optionally placed over the periphery of the substrate 140. Lift pins 138 are moveably disposed through the substrate support 130 to move the substrate 140 to and from the substrate receiving surface 132. The substrate support 130 may also include heating and/or cooling elements 139 to maintain the substrate support 130 at a desired temperature. The substrate support 130 may also include grounding straps 131 to provide radio frequency (RF) grounding at the periphery of the substrate support 130.
A gas source 120 is coupled to the backing plate 112 to provide one or more gases through a gas inlet 142 in the backing plate 112. The gas travels through the gas inlet 142 and through gas passages 111 in the diffuser 110 to a processing region 180 above the substrate 140. A vacuum pump 109 is coupled to the chamber 100 to control the chamber interior volume 106 and the processing region 180 at a desired pressure.
The diffuser 110 includes a first or upstream side 113 and a second or downstream side 116. Each of the gas passages 111 are formed through the diffuser 110 to allow gas transfer from the upstream side 113 to the downstream side 116 to the processing region 180. A radio frequency (RF) power source 122 may be coupled to the backing plate 112 to provide RF power to the diffuser 110. The backing plate 112, which is shown supported by the lid 123, may be electrically isolated from other portions of the chamber 100 by an insulator 185. The RF power applied to the diffuser creates an electric field between the diffuser 110 and the substrate support 130 so that a plasma may be generated from gases in the processing region 180. Various frequencies may be used, such as a frequency between about 0.3 MHz and about 200 MHz, such as a RF power provided at a frequency of 13.56 MHz.
A remote plasma source 124, such as an inductively coupled or microwave remote plasma source, may also be coupled between the gas source 120 and the gas inlet 142 formed in the backing plate 112. Between processing substrates, a cleaning gas may be provided to the remote plasma source 124 so that a remote plasma is generated and provided within the chamber 100 to clean chamber components. The cleaning gas may be further excited by RF current supplied by the RF power source 122 to the diffuser 110. Suitable cleaning gases include but are not limited to NF3, F2, and SF6.
The diffuser 110 is coupled to the backing plate 112 at an edge portion of the diffuser 110 by a suspension 114. The suspension 114 may be flexible to allow expansion and contraction of the diffuser 110. In the embodiment shown in
One or more diffuser support members 160 are moveably disposed through respective openings 165 in backing plate 112 and are coupled to the diffuser 110. The diffuser support members 160 are coupled to a frame structure 175. The material of the diffuser support members 160 may be any process compatible material of sufficient strength to support the diffuser 110, such as metals, alloys, polymers, ceramics, aluminum, titanium, and combinations thereof. The diffuser supports 160 are preferably coupled to a center area of the diffuser 110. Since the diffuser support members 160 are moveably disposed through the backing plate 112, the diffuser support members 160 may support the center area of diffuser 110 in any desired position independent of the position of the center area of the backing plate 112.
The center area of the diffuser 110 is defined herein as a location within a radius R from the center of the diffuser, wherein R is 25% or less of the diagonal of the diffuser, preferably 15% or less of the diagonal of the diffuser, more preferably 10% or less of the diagonal of the diffuser. For instance, if the dimensions of a diffuser are 2.3 meters in length and 2.0 meters in width, the diagonal would be about 3.0 meters.
As shown in
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While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
Claims
1. A gas distribution apparatus, comprising:
- a diffuser,
- a backing plate, and
- a diffuser support member moveably disposed through the backing plate and coupled to the diffuser.
2. The apparatus of claim 1, wherein a spacing between the backing plate and the diffuser is variable.
3. The apparatus of claim 1, wherein the backing plate further comprises an opening wherein the diffuser support member is moveably disposed therethrough.
4. The apparatus of claim 3, further comprising a sealing device associated with the diffuser support member.
5. The apparatus of claim 4, wherein the sealing device provides a vacuum seal for the opening in the backing plate.
6. The apparatus of claim 5, wherein the sealing device comprises an o-ring in sliding contact with the diffuser support member.
7. The apparatus of claim 5, wherein the sealing device comprises an o-ring in sliding contact with the opening of the backing plate.
8. The apparatus of claim 5, wherein the sealing device comprises a flexible bellows.
9. The apparatus of claim 1, wherein the diffuser support member is coupled to a center region of the diffuser.
10. The apparatus of claim 1, wherein the backing plate is coupled to an edge portion of the diffuser.
11. A gas distribution apparatus, comprising:
- a chamber body including a bottom and walls,
- a backing plate disposed over the chamber body,
- a chamber interior volume bounded by the chamber body and the backing plate,
- a diffuser disposed within the chamber interior volume, and
- a diffuser support member moveably disposed through the backing plate and coupled to the diffuser.
12. The apparatus of claim 11, further comprising a frame structure disposed outside of the chamber interior volume wherein the diffuser support member is coupled to the frame structure.
13. The apparatus of claim 12, wherein the frame structure is electrically isolated from the diffuser support member.
14. The apparatus of claim 12, further comprising a coupling assembly coupling the diffuser support member and the frame structure.
15. The apparatus of claim 14, wherein coupling assembly comprises a hanger coupled to the frame structure and a support ring coupled to the hanger and the diffuser support member.
16. The apparatus of claim 15, wherein support ring comprises an insulative material.
17. The apparatus of claim 15, wherein the support ring comprises a conductive material.
18. The apparatus of claim 11, further comprising an insulative sleeve disposed at least partially around the diffuser support member.
19. The apparatus of claim 15, further comprising an insulative sleeve disposed at least partially around the hanger.
20. The apparatus of claim 12, further comprising a cover over the frame structure to provide electrical isolation thereof.
21. A gas distribution apparatus, comprising:
- a diffuser,
- a backing plate,
- a diffuser support member moveably disposed through the backing plate and coupled to the diffuser, and
- a variable spacing between the backing plate and the diffuser.
22. The apparatus of claim 21, further comprising a vacuum pump providing a vacuum force to the backing plate.
23. The apparatus of claim 21, wherein the variable spacing between the backing plate and the diffuser is a function of the vacuum pressure applied to backing plate
24. The apparatus of claim 21, wherein movement of the backing plate causes the variable spacing between the backing plate and the diffuser.
25. A method of processing a substrate on a substrate receiving surface of a substrate support, comprising:
- providing a diffuser within a chamber interior volume bounded by a chamber body and a backing plate,
- supporting the diffuser with a diffuser support member moveably disposed through the backing plate,
- applying a vacuum pressure within the chamber interior volume wherein the backing plate flexes in response to the vacuum pressure, and
- delivering a gas through the diffuser towards the substrate receiving surface of the substrate support.
26. The method of claim 25, further comprising applying an RF power to the diffuser.
27. The method of claim 25, wherein a spacing between the backing plate and the diffuser is variable.
28. A method of processing a substrate within a chamber, comprising:
- providing a chamber interior volume bounded by walls, a bottom, and a backing plate;
- providing a diffuser within the chamber volume;
- providing a diffuser support member moveably disposed through the backing plate and coupled to the diffuser; and
- coupling the diffuser support member to a structure outside of the chamber interior volume.
29. The method of claim 28, insulating the structure from a RF power provided to the diffuser.
30. The method of claim 28, providing a sealing device to isolate the chamber interior volume and to allow movement of the diffuser support member through the backing plate.
31. The method of claim 28, wherein the sealing device comprises an o-ring in sliding contact to the diffuser support member.
32. The method of claim 28, wherein the sealing device comprises an o-ring in sliding contact to an opening through the backing plate.
33. The method of claim 28, wherein the sealing device is a flexible bellows surrounding at least a portion of the diffuser support member.
Type: Application
Filed: Jun 22, 2007
Publication Date: Dec 25, 2008
Inventors: John M. White (Hayward, CA), Robin L. Tiner (Santa Cruz, CA), Yeh Kurt Chang (San Jose, CA)
Application Number: 11/767,307
International Classification: C23C 16/00 (20060101); H05H 1/24 (20060101);