Apparatus for supporting a substrate and introducing gas flow doximate to an edge of the substrate

Claims

What is claimed is:

1. An apparatus for supporting a substrate in a process chamber of a chemical vapor deposition reactor, the substrate having a thickness and a shape, comprising:

a platen mounted in the process chamber, the platen having a gas orifice defining a periphery of an interior region, the interior region having a surface, the surface having a shape substantially coextensive with the shape of the substrate, and the platen further having an exterior region surrounding the interior region; and

a projecting member having an inner surface surrounding a volume, the volume being peripherally coextensive with the interior region, the projecting member extending from the exterior region, the inner surface of the projecting member extending to at least the thickness of the substrate, and the inner surface of the projecting member being approximately uniformly spaced apart from a periphery of the volume.

2. The apparatus as in claim 1 wherein the projecting member comprises a ring removably coupled to the platen.

3. The apparatus as in claim 2 wherein the ring is alumina.

4. The apparatus as in claim 2 wherein the ring includes at least two registration points, and the platen includes two registration points.

5. The apparatus as in claim 1 wherein the projecting member comprises a raised portion of the platen.

6. The apparatus as in claim 5 wherein the platen and the raised portion thereof are aluminum.

7. The apparatus as in claim 1 wherein the gas orifice is a continuous, annular gas groove.

8. The apparatus as in claim 7 wherein a gas flow restriction is formed in the gas groove.

9. The apparatus as in claim 8 wherein the restriction comprises a ring contained in the gas groove.

10. The apparatus as in claim 9 wherein a major surface of the ring is spaced apart from an inside surface of the gas groove to provide a restricted passage.

11. The apparatus as in claim 10 wherein the restricted passage has a thickness and wherein the ring lies in a plane and has a dimension normal to the plane that is at least ten times larger than the thickness of the restricted passage.

12. The apparatus as in claim 11 wherein the platen and the ring are aluminum.

13. The apparatus as in claim 1 further comprising an additional gas orifice extending from an upper surface of the projecting member and merging with the gas orifice.

14. The apparatus as in claim 13 wherein the gas orifice is a groove, and the additional gas orifice comprises a plurality of holes merging with the groove.

15. The apparatus as in claim 14 wherein the gas orifice is a groove, further comprising a plurality of uniformly spaced holes merging with the groove from the top of the projecting member.

16. The apparatus as in claim 1 wherein the platen includes a vacuum chuck.

17. The apparatus as in claim 1 wherein the inner surface is substantially vertical and extends from the exterior region.

18. The apparatus as in claim 1 wherein the gas orifice is a continuous, annular gas groove.

19. The apparatus as in claim 1 wherein a basal surface of the projecting member extends over a portion of the gas orifice.

20. The apparatus as in claim 1 wherein when the platen supports the substrate, a restriction to a gas flow is formed between an edge of the substrate and the projecting member inner surface.

21. The apparatus as in claim 20 wherein the inner surface of the projecting member is uniformly spaced approximately 0.50 mm from an edge of the substrate.

22. The apparatus as in claim 1 wherein the interior region supports the substrate, and a peripheral edge of the substrate extends partially over the gas orifice.

23. The apparatus as in claim 1 wherein the projecting member includes a second gas orifice extending through the projecting member into the gas orifice.

24. The apparatus as in claim 23 wherein the second gas orifice comprises a plurality of through holes directed away from the interior region.

25. The apparatus as in claim 1 wherein the projecting member is an integral feature of the platen.

26. The apparatus as in claim 1 wherein an approximately uniform restriction to a gas flow is formed between the projecting member and a perimeter of the interior region.

27. An apparatus for supporting a substrate in a process chamber of a chemical vapor deposition reactor, the substrate having a thickness and a shape, comprising:

a platen mounted in the process chamber, the platen having a continuous gas groove defining a periphery of an interior surface region having a shape substantially coextensive with the shape of the substrate, the platen further having a wafer chuck and an exterior region surrounding and separated from the interior surface region by the gas groove; and

a flow restrictor disposed in the gas groove.

28. The apparatus as in claim 27 wherein the flow restrictor is a ring disposed in the gas groove.

29. The apparatus as in claim 27 wherein the wafer chuck is a vacuum chuck.

30. The apparatus as in claim 27 further comprising:

a projecting member having an inner surface surrounding a volume, the volume being peripherally coextensive with the interior surface region, the projecting member extending from the exterior region to at least the thickness of the substrate, and the inner surface of the projecting member being approximately uniformly spaced apart from a periphery of the volume.

31. The apparatus as in claim 27 wherein the flow restrictor comprises an insert attached to a first side of the gas groove proximate to the interior surface region, and an approximately uniform space separates the insert from a second side of the gas groove, the first and second sides facing each other.

32. An apparatus for supporting a substrate having a shape in a process chamber of a chemical vapor deposition reactor, comprising:

a platen disposed in the process chamber, the platen having a surface of a shape substantially coextensive with the shape of the substrate for contacting a backside of the substrate;

a member disposed in the process chamber such that an inner wall thereof surrounds a volume peripherally coextensive with the surface with an approximately uniform space between the inner wall and a periphery of the volume normal to the surface, wherein the space is in substantially uniform communication with a volume overlying the surface and member; and

a gas source in communication with the space.

33. The apparatus as in claim 32 wherein the member includes a gas orifice extending through the member to the gas source.

34. The apparatus as in claim 32 wherein the inner surface is a substantially vertical surface.

35. A chemical vapor deposition system for processing a wafer comprising:

a process chamber;

a platen disposed in the process chamber, the platen having a gas orifice defining a periphery of an interior surface region, the interior surface region having a shape substantially coextensive with the shape of the wafer, and the platen further having an exterior region surrounding the interior surface region; and

a projecting member having an inner surface surrounding a volume peripherally coextensive with the interior surface region, the projecting member extending from the exterior region, and the inner surface of the projecting member being approximately uniformly spaced apart from a periphery of the volume normal to the interior surface region.

36. The chemical vapor deposition system as in claim 35 wherein the projecting member comprises a raised portion of the platen and the projecting member extends to at least a thickness of the wafer.

37. The chemical vapor deposition system as in claim 35 wherein the gas orifice is an annular gas groove.

38. The chemical vapor deposition system as in claim 35 wherein the gas orifice is an annular groove, and an insert is fixed against a wall of the gas groove with an approximately uniform space separating the other wall of the gas groove from the insert.

39. The chemical vapor deposition system as in claim 38 wherein the insert has a thickness and the uniform space has a width such that the thickness of the insert is 10 times the width of the uniform space.

40. The chemical vapor deposition system as in claim 35 wherein the platen is alumina.

41. The chemical vapor deposition system as in claim 35, the platen further comprising:

a vacuum chuck disposed in the interior region of the platen to secure the wafer to the platen, wherein a backside of the wafer is in substantially full contact with the platen.

42. A chemical vapor deposition apparatus for processing a wafer in a process chamber, the process chamber having an ambient, comprising:

means for supporting the wafer, the wafer being supported on a region of the means for supporting, the region having a shape substantially coextensive with a shape of the wafer for substantially fully contacting a backside of the wafer;

means for securing the wafer to the means for supporting;

means for introducing deposition control gas into a space surrounding an edge of the wafer, the deposition control gas when introduced having a pressure; and

means for surrounding the space to equalize the deposition control gas pressure in the space when the deposition control gas is introduced by the means for introducing, the means for surrounding being separated from the wafer.

43. The chemical vapor deposition apparatus as in claim 42 wherein the supporting means includes a platen.

44. The chemical vapor deposition apparatus as in claim 42 wherein the means for introducing deposition control gas includes a gas groove surrounding the region of the supporting means.

45. The chemical vapor deposition apparatus as in claim 42 wherein the means for surrounding is a ring removably coupled to the means for supporting.

46. The chemical vapor deposition apparatus as in claim 45 wherein the means for supporting and the means for surrounding are aluminum.

47. The chemical vapor deposition apparatus as in claim 42 wherein the means for surrounding includes a gas orifice extending through the means for surrounding from the means for introducing and directed away from the wafer.