Gas diffuser having varying thickness and nozzle density for semiconductor device fabrication and reaction furnace with gas diffuser

• US 6,113,700 A
• Filed: 12/15/1998
• Issued: 09/05/2000
• Est. Priority Date: 12/30/1997
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Choi, Jun-young
• Primary Examiner(s): Beck, Shrive
• Assistant Examiner(s): MACARTHUR, SYLVIA
• Application Number:
  US09/210,592
• Time in Patent Office: 630 Days
• Field of Search: 118/715, 156/345, 204/298.07
• US Class Current: 118/715
• CPC Class Codes: C23C 16/455 characterised by the method used for introducing gases into reaction chamber or for modifying gas flows in reaction chamber
• CPC Class Codes: C23C 16/45502 Flow conditions in reaction chamber
• CPC Class Codes: C23C 16/45565 Shower nozzles
• CPC Class Codes: C30B 25/14 Feed and outlet means for the gases; Modifying the flow of the reactive gases
• CPC Class Codes: H01L 21/67017 Apparatus for fluid treatment H01L21/67126, H01L21/6715 take precedence

Abstract

A gas diffuser for semiconductor device fabrication has the form of a hermetic cylinder with a hollow formed therein and is provided with a gas inlet opened upward for the gas to flow into the hollow, and a disk-shaped diffusion plate disposed in the lower side thereof with a plurality of nozzles to direct and control the stream of the gas pouring out of the hollow. The thickness of the diffusion plate increases with radial distance from the center thereof, such that lengths of the nozzles through which the gas passes also increase with radial distance from the center of the diffusion plate. A reaction furnace has the gas diffuser disposed in an upper portion thereof, and a support plate for supporting the wafer disposed in a lower portion thereof. The distance from the surface of the wafer to the diffusion plate of the gas diffuser is half the radius of the wafer.

Claims

1. A gas diffuser for fabricating a semiconductor device, comprising:

a hermetic cylinder with a hollow formed therein;

a gas inlet opened upward disposed in an upper side of the hermetic cylinder for a gas to flow into the hollow;

a disk-shaped diffusion plate disposed in a lower side of the hermetic cylinder; and

a plurality of nozzles formed in the diffusion plate to direct and control a stream of the gas pouring out of the hollow,

wherein a thickness of the diffusion plate increases with radial distance from a center thereof, such that lengths of the nozzles through which the gas passes also increase with radial distance from the center of the diffusion plate.

2. The gas diffuser as defined in claim 1, wherein the thickness of the diffusion plate increases in proportion to the radial distance from the center of the diffusion plate.

3. The gas diffuser as defined in claim 1, wherein the thickness of the diffusion plate increases in proportion to a square of the radial distance from the center of the diffusion plate.

4. The gas diffuser as defined in claim 1, wherein the thickness of the diffusion plate increases in proportion to a repetitive multiple of the radial distance from the center of the diffusion plate with a degree of 2 or greater.

5. The gas diffuser as defined in claim 1, wherein the diffusion plate has a lower surface which is flat and horizontally disposed.

6. The gas diffuser as defined in claim 5, wherein the nozzles are straight tubes which pierce the diffusion plate perpendicular to the lower surface thereof.

7. The gas diffuser as defined in claim 1, wherein the nozzles have an identical radius.

8. The gas diffuser as defined in claim 1, wherein the gas is an etching gas.

9. The gas diffuser as defined in claim 1, wherein the gas is a vapor deposition gas.

10. A gas diffuser for fabricating a semiconductor device, comprising:

a hermetic cylinder with a hollow formed therein;

a gas inlet opened upward disposed in an upper side of the hermetic cylinder for a gas to flow into the hollow;

a disk-shaped diffusion plate disposed in a lower side of the hermetic cylinder; and

a plurality of nozzles formed in the diffusion plate to direct and control a stream of the gas pouring out of the hollow,

wherein a thickness of the diffusion plate increases with radial distance from the center thereof, such that lengths of the nozzles through which the gas passes also increase with radial distance from the center of the diffusion plate, and

a velocity distribution of diffused gas at a position directly under the diffusion plate and spaced a radial distance "r" from a position directly under a center of the diffusion plate is

space="preserve" listing-type="equation">V(r)=V.sub.0 ((r/r.sub.0).sup.2 -1),

wherein r₀ is a radius of the diffusion plate, and V₀ is a velocity of gas at the position directly under the center of the diffusion plate.

11. The gas diffuser as defined in claim 10, wherein the diffusion plate has a lower surface which is flat and horizontally disposed.

12. The gas diffuser as defined in claim 10, wherein the gas is an etching gas.

13. The gas diffuser as defined in claim 10, wherein the gas is a vapor deposition gas.

14. A gas diffuser for fabricating a semiconductor device, comprising:

a hermetic cylinder with a hollow formed therein;

a gas inlet opened upward disposed in an upper side of the hermetic cylinder for a gas to flow into the hollow;

a disk-shaped diffusion plate disposed in a lower side of the hermetic cylinder; and

a plurality of nozzles formed in the diffusion plate to direct and control a stream of the gas pouring out of the hollow,

wherein a thickness of the diffusion plate increases with radial distance from the center thereof, such that lengths of the nozzles through which the gas passes also increase with radial distance from the center of the diffusion plate, and

a concentration distribution of diffused gas at a defined position directly under the diffusion plate and spaced a radial distance "r" from a position directly under a center of the diffusion plate is ##EQU4## wherein ω

_k (r) is a Chebyshev polynomial, N_k is a number of polynomials, and a_k is a proportional constant, wherein ω

_k (r) represents a Chebyshev polynomial of 2(k-1) order because the polynomial used is of an even order in consideration of geometrical form and symmetric points with respect to a boundary position at r=0.

15. The gas diffuser as defined in claim 14, wherein a distance in a radial direction of the diffusion plate between radially adjacent nozzles decreases and then increases as radial distance between the nozzles and the center of the diffusion plate increases, such that density of nozzles is low in the center of the diffusion plate, high at a distance from the center of the diffusion plate, and then low again toward peripheral edges of the diffusion plate.

16. The gas diffuser as defined in claim 14, wherein the diffusion plate has a lower surface which is flat and horizontally disposed.

17. The gas diffuser as defined in claim 16, wherein the nozzles are straight tubes which pierce the diffusion plate perpendicular to the lower surface thereof.

18. The gas diffuser as defined in claim 14, wherein the nozzles have an identical radius.

19. The gas diffuser as defined in claim 14, wherein the gas is an etching gas.

20. The gas diffuser as defined in claim 14, wherein the gas is a vapor deposition gas.

21. A gas diffuser for fabricating a semiconductor device, comprising:

a hermetic cylinder with a hollow formed therein;

a gas inlet opened upward disposed in an upper side of the hermetic cylinder for a gas to flow into the hollow;

a disk-shaped diffusion plate disposed in a lower side of the hermetic cylinder; and

a plurality of nozzles formed in the diffusion plate to direct and control a stream of the gas pouring out of the hollow,

wherein a thickness of the diffusion plate increases with radial distance from a center thereof, such that lengths of the nozzles through which the gas passes also increase with radial distance from the center of the diffusion plate, and

radial distance between radially adjacent nozzles decreases and then increases as radial distance between the nozzles and the center of the diffusion plate increases, such that density of nozzles is low in the center of the diffusion plate, high at a distance from the center of the diffusion plate, and then low again toward peripheral edges of the diffusion plate.

22. The gas diffuser as defined in claim 21, wherein the thickness of the diffusion plate increases in proportion to the radial distance from the center of the diffusion plate.

23. The gas diffuser as defined in claim 21, wherein the thickness of the diffusion plate increases in proportion to a square of the radial distance from the center of the diffusion plate.

24. The gas diffuser as defined in claim 21, wherein the thickness of the diffusion plate increases in proportion to a repetitive multiple of the radial distance from the center of the diffusion plate with a degree of 2 or greater.

25. The gas diffuser as defined in claim 21, wherein a decrement or increment of the distance between radially adjacent nozzles is proportional to the radial distance from the center of the diffusion plate.

26. The gas diffuser as defined in claim 21, wherein a decrement or increment of the distance between radially adjacent nozzles is proportional to a repetitive multiple of the radial distance from the center of the diffusion plate with a degree of 2 or greater.

27. The gas diffuser as defined in claim 21, wherein the diffusion plate has a lower surface which is flat and horizontally disposed.

28. The gas diffuser as defined in claim 27, wherein the nozzles are straight tubes which pierce the diffusion plate perpendicular to the lower surface thereof.

29. The gas diffuser as defined in claim 21, wherein the nozzles have an identical radius.

30. The gas diffuser as defined in claim 21, wherein the gas is an etching gas.

31. The gas diffuser as defined in claim 21, wherein the gas is a vapor deposition gas.

32. A gas diffuser for fabricating a semiconductor device, comprising:

a hermetic cylinder with a hollow formed therein;

a gas inlet opened upward disposed in an upper side of the hermetic cylinder for a gas to flow into the hollow;

a disk-shaped diffusion plate disposed in a lower side of the hermetic cylinder; and

a plurality of nozzles formed in the diffusion plate to direct and control a stream of the gas pouring out of the hollow,

wherein a thickness of the diffusion plate increase with radial distance from the center thereof, such that lengths of the nozzles through which the gas passes also increase with radial distance from the center of the diffusion plate, and

a velocity distribution of diffused gas at a position directly under the diffusion plate and spaced a radial distance "r" from a position directly under a center of the diffusion plate is

space="preserve" listing-type="equation">V(r)=V.sub.0 ((r/r.sub.0).sup.2 -1),

wherein r₀ is a radius of the diffusion plate, and V₀ is a velocity of gas at the position directly under the center of the diffusion plate, and

a concentration distribution of diffused gas at a position directly under the diffusion plate and spaced a radial distance "r" from a position directly under the center of the diffusion plate is ##EQU5## wherein ω

_k (r) is a Chebyshev polynomial, N_k is a number of polynomials, and a_k is a proportional constant, wherein ω

_k (r) represents a Chebyshev polynomial of 2(k-1) order because the polynomial used is of an even order in consideration of geometrical form and symmetric points with respect to a boundary position at r=0.

33. The gas diffuser as defined in claim 32, wherein a distance in a radial direction of the diffusion plate between radially adjacent nozzles decreases and then increases as radial distance between the nozzles and the center of the diffusion plate increases, such that density of nozzles is low in the center of the diffusion plate, high at a distance from the center of the diffusion plate, and then low again toward peripheral edges of the diffusion plate.

34. The gas diffuser as defined in claim 32, wherein the diffusion plate has a lower surface which is flat and horizontally disposed.

35. The gas diffuser as defined in claim 32, wherein the gas is an etching gas.

36. The gas diffuser as defined in claim 32, wherein the gas is a vapor deposition gas.

37. A reaction furnace for fabricating a semiconductor device comprising:

a gas diffuser disposed in an upper portion of the reaction furnace for injecting a gas onto a surface of a wafer; and

a support plate disposed in a lower portion of the reaction furnace for supporting the wafer, wherein the gas diffuser comprises;

a hermetic cylinder with a hollow formed therein;

a gas inlet opened upward disposed in an upper side of the hermetic cylinder for the gas to flow into the hollow;

a disk-shaped diffusion plate disposed in a lower side of the hermitic cylinder; and

a plurality of nozzles formed in the diffusion plate to direct and control a stream of the gas pouring out of the hollow,

wherein a thickness of the diffusion plate increases with radial distance from a center thereof, such that lengths of the nozzles through which the gas passes also increase with radial distance from the center of the diffusion plate, and

the diffusion plate being disposed in the upper portion of the reaction furnace spaced from the surface of the wafer by a distance equal to half a radius of the wafer.

38. The reaction furnace as defined in claim 37, wherein a distance in a radial direction of the diffusion plate between radially adjacent nozzles decreases and then increases as radial distance between the nozzles and a center of the diffusion plate increases, such that density of nozzles is low in the center of the diffusion plate, high at a distance from the center of the diffusion plate, and then low again toward peripheral edges of the diffusion plate.

39. The reaction furnace as defined in claim 37, wherein a gas exhaust hole is disposed under the wafer in order to discharge the gas downwards with a vacuum pressure.

40. The reaction furnace as defined in claim 37, wherein the diffusion plate has a lower surface which is flat and horizontally disposed in the reaction furnace.

41. The reaction furnace as defined in claim 40, wherein the nozzles are straight tubes which pierce the diffusion plate perpendicular to the lower surface thereof.

42. The gas diffuser as defined in claim 37, wherein the nozzles have an identical radius.

43. The gas diffuser as defined in claim 37, wherein the gas is an etching gas.

44. The gas diffuser as defined in claim 37, wherein the gas is a vapor deposition gas.

45. A reaction furnace for fabricating a semiconductor device comprising:

a gas diffuser disposed in an upper portion of the reaction furnace for injecting a gas onto a surface of a wafer; and

a support plate disposed in a lower portion of the reaction furnace for supporting the wafer, wherein the gas diffuser comprises;

a hermetic cylinder with a hollow formed therein;

a gas inlet opened upward disposed in an upper side of the hermetic cylinder for the gas to flow into the hollow;

a disk-shaped diffusion plate disposed in a lower side of the hermetic cylinder; and

a plurality of nozzles formed in the diffusion plate to direct and control a stream of the gas pouring out of the hollow,

wherein a thickness of the diffusion plate increases with radial distance from a center thereof, such that lengths of the nozzles through which the gas passes also increase with radial distance from the center of the diffusion plate, and

the diffusion plate being disposed in the upper portion of the reaction furnace space from the surface of the wafer by a distance equal to a radius of the wafer.

46. The reaction furnace as defined in claim 45, wherein a distance in a radial direction of the diffusion plate between radially adjacent nozzles decreases and then increases as radial distance between the nozzles and a center of the diffusion plate increases, such that density of nozzles is low in the center of the diffusion plate, high at a distance from the center of the diffusion plate, and the low again toward peripheral edges of the diffusion plate.

47. The reaction furnace as defined in claim 45, wherein a gas exhaust hole is disposed under the wafer in order to discharge the gas downwards with a vacuum pressure.

48. The reaction furnace as defined in claim 45, wherein the diffusion plate has a lower surface which is flat and horizontally disposed in the reaction furnace.

49. The reaction furnace as defined in claim 48, wherein the nozzles are straight tubes which pierce the diffusion plate perpendicular to the lower surface thereof.

50. The gas diffuser as defined in claim 45, wherein the nozzles have an identical radius.

51. The gas diffuser as defined in claim 45, wherein the gas is an etching gas.

52. The gas diffuser as defined in claim 45, wherein the gas is a vapor deposition gas.