Sublimation bed employing carrier gas guidance structures

• US 20050072357A1
• Filed: 07/29/2003
• Published: 04/07/2005
• Est. Priority Date: 07/30/2002
• Status: Active Grant

• Current Assignee: ASM IP Holding B.V. (ASM International NV)
• Original Assignee: ASM America Incorporated (ASM International NV)
• Inventors: Shero, Eric J., Schmidt, Ryan, Givens, Michael E.
• Granted Patent: US 7,122,085 B2
• Time in Patent Office: Days
• US Class Current: 118/715
• CPC Class Codes: C23C 16/4481 by evaporation using carrier gas in contact with the source material C23C16/4486 takes precedence
• CPC Class Codes: C23C 16/4483 using a porous body
• CPC Class Codes: C23C 16/45544 characterized by the apparatus

Abstract

Preferred embodiments of the present invention provides a sublimation system employing guidance structures including certain preferred embodiments having a high surface area support medium onto which a solid source material for vapor reactant is coated. Preferably, a guidance structure is configured to facilitate the repeated saturation of the carrier gas with the solid source for a vapor reactant. Methods of saturating a carrier gas using guidance structures are also provided.

Claims

1. A substrate processing system comprising:

a source of a carrier gas;

a support medium having a surface onto which a solid source for vapor reactant is coated, the support medium being configured to guide the carrier gas through the support medium, the coated support medium collectively forming a bed, the source of carrier gas being connected upstream of the support medium; and

a reaction chamber connected downstream of the support medium.

2. The system according to claim 1, wherein the support medium is configured to remain substantially stationary during the saturation of the carrier gas.

3. The system according to claim 1, wherein the reaction chamber is an atomic layer deposition (ALD) chamber.

4. The system according to claim 1, wherein the support medium is configured to guide the carrier gas in a convoluted contact path.

5. The system according to claim 1, further including a sublimation vessel, located downstream of the carrier gas source and upstream of the reaction chamber, the support medium being located in the vessel, the solid source coating having a ratio of total exposed surface area to bed volume greater than about 0.1 cm⁻

1.

6. The system according to claim 1, wherein the bed is formed from a plurality of packed flowable support elements.

7. The system according to claim 1, wherein the support medium has a shape selected from a group consisting of beads, rings, cylinders, and filaments.

8. The system according to claim 1, wherein the solid source coating has a ratio of total exposed surface area to bed volume greater than about 1 cm⁻

1.

9. The system according to claim 1, further comprising a heat source capable of increasing the vaporization of the solid source for vapor reactant.

10. The system according to claim 1, further comprising a vessel containing the support medium, the system being configured to pulse a substantially plug flow residence time distribution of both the carrier gas and the vapor reactant through the vessel.

11. An atomic layer deposition (ALD) semiconductor processing system comprising:

a source of carrier gas;

a support medium onto which a solid source for vapor reactant is coated, the support medium being configured to guide the carrier gas in a generally non-parallel contact path, the support medium being further configured to facilitate the saturation of the carrier gas over each of a plurality of pulses;

a reaction chamber located downstream of the support medium; and

a pulsing mechanism configured to provide pulses of saturated carrier gas from the support medium to the reaction chamber, wherein the support medium is further configured to facilitate the repeated saturation of the carrier gas with the vapor reactant for greater than 100,000 pulses, each pulse lasting for about 0.1-10 seconds.

12. The atomic layer deposition (ALD) system according to claim 11, wherein the support medium is further configured to facilitate the repeated saturation of the carrier gas with the vapor reactant when the time between successive pulses of the vapor reactant is greater than 0.400 seconds and less than about 10 seconds.

13. The atomic layer deposition (ALD) system according to claim 11, wherein the support medium is further configured to guide the carrier gas through multiple generally non-parallel contact pathways.

14. A semiconductor processing system for fabricating a substrate comprising a plurality of flowable support elements onto which a solid source for vapor reactant is coated, the support elements being packed into a vessel and configured to guide the through the support elements in a tortuous contact path.

15. The system of claim 14, wherein the support elements are further configured to facilitate the repeated saturation of gas exiting the vessel with the solid source for a vapor reactant for greater than 100,000 pulses, each pulse lasting for about 0.1-10 seconds with the time between successive pulses being no less than 30 seconds.

16. The system of claim 14, further comprising:

a carrier gas source located upstream of the inlet port; and

a chemical vapor deposition (CVD) chamber located downstream of the outlet port.

17. The system of claim 14, further comprising:

a carrier gas source located upstream of the inlet port; and

an atomic layer deposition (ALD) reactor located downstream of the outlet port.

18. A sublimation apparatus comprising:

a sublimation vessel;

an inlet port leading into the vessel;

an outlet port leading out of the vessel;

a solid source for vapor reactant contained within the vessel; and

a support medium having a coating of a solid source for vapor reactant, the coating having a ratio of exposed surface area to support medium volume greater than about 0.1 cm<sup>−

1</sup>.

19. The apparatus according to claim 18, configured to draw the vapor reactant through the support medium and out of the outlet port via convective transfer.

20. The apparatus according to claim 18, configured to guide a carrier gas through the support medium.

21. The apparatus according to claim 18, wherein the support medium is configured to be substantially stationary once inserted into the sublimation vessel.

22. The apparatus according to claim 18, further including a manifold located in the sublimation vessel, the manifold being configured to distribute a carrier gas across the vessel to contact the coated support medium.

23. The apparatus according to claim 18, wherein the sublimation vessel is configured to have the inlet port and the outlet port located at opposite ends of the vessel.

24. The apparatus according to claim 23, wherein the sublimation vessel is a cylinder.

25. The apparatus according to claim 18, wherein the support medium is formed from flowable support elements packed into the vessel.

26. The apparatus according to claim 25, wherein the support elements have shapes selected from a group consisting of beads, cylinders, filaments and rings.

27. The apparatus according to claim 18, wherein the support medium is a fixed support medium.

28. The apparatus according to claim 27, wherein the fixed support medium coated with solid source for vapor reactant is selected from the group consisting of a tube, a coiled tube, a bundle of tubes, a filter, and a multiple intersecting plate structure.

29. The apparatus according to claim 27, wherein the fixed support medium is configured to substantially conform to the shape of the sublimation vessel.

30. The apparatus according to claim 18, wherein the support medium is configured to guide the carrier gas through a generally tortuous contact path.

31. The apparatus according to claim 18, wherein the support medium is a substantially inert, thermally conductive support medium.

32. The apparatus according to claim 31, wherein the support medium comprises a material selected from the group consisting of alumina (Al₂O₃), fused silica, stainless steel, hastelloy, nickel, silicon carbide (SiC), and boron nitride (BN).

33. The apparatus according to claim 18, further comprising a heat source capable of increasing the vaporization of the solid source for vapor reactant.

34. The apparatus according to claim 18, wherein the solid source for vapor reactant coating is hafnium chloride (HfCl₄).

35. The apparatus according to claim 18, wherein the solid source for vapor reactant coating is zirconium chloride (ZrCl₄).

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44. A sublimation apparatus for producing a reactant vapor for flowing through a reaction chamber comprising:

a sublimation vessel;

a bed of a solid source for the vapor reactant, the solid source bed contained within the vessel;

a carrier gas guidance structure with which the solid source is directly in contact, the guidance structure being configured to guide the carrier gas to contact the vapor reactant from the bed of the solid source by providing a substantially segregating and winding contact pathway for a carrier gas;

a vessel inlet port located at the beginning of the unitary contact pathway provided by the carrier gas guidance structure; and

a vessel outlet port located at the end of the unitary contact pathway provided by the carrier gas guidance structure, wherein the carrier gas guidance structure is configured to ensure contact of the carrier gas with the vapor reactant along a the substantially segregated and winding contact pathway having a length greater than about 2.5 times a linear distance measured from the inlet port to the outlet port.

45. The sublimation apparatus according to claim 44, wherein the solid source for vapor reactant forming the sublimation bed is in the form of a solid powder.

46. The sublimation apparatus according to claim 45, wherein the guidance structure is a flow guide configured to extend from a sublimation vessel floor to a sublimation vessel ceiling.

47. The sublimation apparatus according to claim 46, wherein the bed is a single continuous bed and the flow guide is configured to guide the carrier gas in a helical path in contact with the bed of the solid source.

48. The sublimation apparatus according to claim 44, wherein the guidance structure is configured to guide the carrier gas in a helical path, the guidance structure comprising a plurality of levels within the vessel with each level containing a batch of the solid source for vapor reactant.

49. The sublimation apparatus according to claim 48, wherein the guidance structure further comprises a plurality of stacked trays partially defining levels of the helical path.

50. The sublimation apparatus according to claim 49, wherein at least one of the plurality of stacked trays is a guided tray comprising at least one substantially circular pathway, the guided tray being configured to guide the carrier gas at least one lap of at least about 200°

around the guided tray before channeling the carrier gas to an adjacent tray.

51. The sublimation apparatus according to claim 49, wherein at least one of the plurality of stacked trays is a guided tray comprising a secondary partial divider which partially defines at least two substantially circular pathways in the guided tray, the secondary partial divider in combination with tray sidewalls being configured to guide the carrier gas about two laps around the guided tray before channeling the gas to an adjacent stacked tray, each lap being at least 200°

around the guided tray.

52. The sublimation apparatus according to claim 51, wherein the secondary partial divider defines at least two substantially circular pathways around the guided tray, the guided tray further comprising at least two substantially circular pathways configured to channel the carrier gas in substantially opposite directions relative to one another.

53. The sublimation apparatus according to claim 44, further comprising a vessel containing the support medium, the system being configured to pulse a substantially plug flow residence time distribution of both the carrier gas and vapor reactant through a vessel from a vessel outlet.

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75. A sublimation apparatus for producing a reactant vapor for flowing through a reaction chamber comprising:

a sublimation vessel;

a bed of a solid source for the vapor reactant, the solid source bed contained within the vessel;

a vapor guidance structure with which the solid source is directly in contact, the guidance structure being configured to guide the vapor reactant from the bed of the solid source by providing a substantially segregating and convoluted contact pathway for the vapor reactant;

a vessel inlet port located at the beginning of the unitary contact pathway provided by the guidance structure; and

a vessel outlet port located at the end of the unitary contact pathway provided by the guidance structure, wherein the guidance structure is configured to transfer the vapor reactant via convective transfer along the substantially segregated and winding contact pathway having a length greater than about 2.5 times a linear distance measured from the inlet port to the outlet port.