Reactor surface passivation through chemical deactivation

• US 20040221807A1
• Filed: 05/07/2004
• Published: 11/11/2004
• Est. Priority Date: 05/09/2003
• 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., Verghese, Mohith
• Granted Patent: US 7,118,779 B2
• Time in Patent Office: Days
• US Class Current: 118/715
• CPC Class Codes: B05D 1/185 applying monomolecular layers B05D1/204 takes precedence
• CPC Class Codes: B05D 1/36 Successively applying liquids or other fluent materials, e.g. without intermediate treatment
• CPC Class Codes: B05D 1/60 Deposition of organic layers from vapour phase vapour phase deposition in general C23C14/00, C23C16/00
• CPC Class Codes: B05D 2203/30 Other inorganic substrates, e.g. ceramics, silicon
• CPC Class Codes: B05D 2518/12 Ceramic precursors (polysiloxanes, polysilazanes)
• CPC Class Codes: B05D 3/044 Pretreatment
• CPC Class Codes: B05D 3/0466 the gas being a non-reacting gas B05D3/0406 takes precedence
• CPC Class Codes: B05D 3/104 Pretreatment of other substrates
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C23C 16/403 of aluminium, magnesium or beryllium
• CPC Class Codes: C23C 16/4404 Coatings or surface treatment on the inside of the reaction chamber or on parts thereof
• CPC Class Codes: C23C 16/45525 Atomic layer deposition [ALD]
• CPC Class Codes: C23C 22/68 using aqueous solutions with pH between 6 and 8
• CPC Class Codes: C30B 25/14 Feed and outlet means for the gases; Modifying the flow of the reactive gases
• CPC Class Codes: H01J 37/32477 characterised by the means for protecting vessels or internal parts, e.g. coatings

Abstract

Protective layers are formed on a surface of an atomic layer deposition (ALD) or chemical vapor deposition (CVD) reactor. Parts defining a reaction space for an ALD or CVD reactor can be treated, in situ or ex situ, with chemicals that deactivate reactive sites on the reaction space surface(s). A pre-treatment step can maximize the available reactive sites prior to the treatment step. With reactive sites deactivated by adsorbed treatment reactant, during subsequent processing the reactant gases have reduced reactivity or deposition upon these treated surfaces. Accordingly, purge steps can be greatly shortened and a greater number of runs can be conducted between cleaning steps to remove built-up deposition on the reactor walls.

Claims

1. A method of treating and operating a reaction space surface of a vapor deposition reactor, comprising:

treating the reaction space surface with a treatment chemical, thereby deactivating the reaction space surface against reaction with a plurality of deposition reactants;

loading a substrate into the reaction space after treating; and

depositing a layer on the substrate by exposing the substrate to the plurality of reactants.

2. The method of claim 1, wherein depositing comprising selectively depositing the layer on the substrate with reduced deposition on the deactivated reaction space surface relative to deposition under the same conditions on an untreated reaction space surface.

3. The method of claim 2, wherein depositing comprises conducting a selective ALD process.

4. The method of claim 1, wherein treating comprises flowing vapor phase treatment chemical through the reaction space.

5. The method of claim 4, wherein flowing the vapor phase treatment chemical comprises entraining the treatment chemical in an inert gas flow.

6. The method of claim 1, wherein treating comprises exposing reactor parts ex situ to the treatment chemical.

7. The method of claim 6, wherein treating comprises dipping reactor parts in a liquid solution including the treatment chemical.

8. The method of claim 6, wherein treating comprises an ex situ gas phase treatment.

9. The method of claim 1, further comprising pre-treating the reaction space surface prior to treating to maximize reaction between the reaction space surface and the treatment chemical.

10. The method of claim 9, wherein pre-treating comprises increasing a density of reactive sites on the reaction space surface to improve a packing density of a protective layer left by the treatment chemical.

11. The method of claim 10, wherein pre-treating comprises exposing the reaction space surface to an oxygen-bearing reactant.

12. A vapor deposition apparatus, comprising:

a plurality of reaction space surfaces defining a reaction space;

a substrate support structure housed within the reaction space; and

a plurality of feed lines connecting the reaction space to sources of vapor phase reactants suitable for a vapor deposition process,

wherein at least some of the reaction space surfaces comprise a surface modification deactivating the at least some surfaces against the vapor deposition process.

13. The apparatus of claim 12, wherein the surface modification comprises a protective layer.

14. The apparatus of claim 13, wherein the protective layer comprises adsorbed treatment chemical having a thickness no more than about two monolayers.

15. The apparatus of claim 13, wherein the protective layer comprises adsorbed organic reactant.

16. The apparatus of claim 13, wherein the protective layer defines a hydrophobic outer surface.

17. The apparatus of claim 12, wherein the surface modification renders the vapor deposition process selective to a semiconductor substrate relative to the at least some surfaces.

18. The apparatus of claim 12, configured for atomic layer deposition by alternated and repeated pulses of the vapor phase reactants.

19. The apparatus of claim 12, further comprising an inlet leading from a source of a treatment reactant to the reaction space, the treatment reactant providing the surface modification to the at least some surfaces.

20. The apparatus of claim 19, wherein the treatment reactant is an alkyldisilazane.

21. The apparatus of claim 19, wherein the treatment reactant is an alkylhalosilane.

22. The apparatus of claim 19, wherein the treatment reactant is an aryldisilazane.

23. The apparatus of claim 19, wherein the treatment reactant is an arylhalosilane.

24. The apparatus of claim 19, further comprising an inlet leading from a source of a pre-treatment reactant to the reaction space, the pre-treatment reactant rendering the at least some surfaces more reactive to the treatment reactant.

25. The apparatus of claim 24, wherein the pre-treatment reactant comprising an oxygen-containing reactant.

26. A deposition system, comprising:

a reactor having a deposition chamber for depositing a film on a substrate, surfaces of the deposition chamber being coated with reactive sites selected from the group consisting of —

OH, nitrogen, hydrogen and halide surface groups;

a substrate support located within the reactor and configured to support the substrate;

a treatment gas source containing a treatment gas; and

an inlet line in flow communication with the treatment gas source and configured to supply the treatment gas to the surfaces of the deposition chamber, the treatment gas being selected to bind to the reactive sites to form a protective layer on the surfaces of the deposition chamber, the protective layer reducing the likelihood of the film depositing on the surfaces of the deposition chamber.

27. The deposition system of claim 26, wherein the protective layer comprises oxygen atoms bonded to the surfaces of the deposition chamber and silicon atoms bonded to the oxygen atoms.

28. The deposition system of claim 27, wherein the protective layer comprises an adsorbed monolayer.

29. The deposition system of claim 26, wherein the treatment gas is an organic silicon precursor.

30. The deposition system of claim 26, wherein the reactor is configured for alternate reactant pulses in an atomic layer deposition sequence.

31. The deposition system of claim 26, further comprising a pre-treatment gas source containing a pre-treatment gas configured to increase a density of the reactive sites on the deposition chamber prior to exposure to the treatment gas.

32. The deposition system of claim 26, further comprising a plurality of deposition reactant gas sources selectively communicating with the deposition chamber.

33. A method of operating a deposition reactor having a reaction space, the method comprising:

contacting a reaction space surface of the reactor with a treatment chemical, thereby forming a protective layer over the reaction space surface;

loading a substrate into the reaction space;

flowing a deposition reactant gas over the protective layer and the substrate; and

preferentially reacting the reactant gas with the substrate as compared to the protective layer, thereby selectively depositing a layer on the substrate.

34. The method of claim 33, wherein contacting comprises an ex situ treatment of reactor parts prior to assembly of the reaction space.

35. The method of claim 34, wherein the treatment chemical is an organic molecule and the protective layer is a self-assembled monolayer.

36. The method of claim 33, wherein preferentially reacting comprises chemical vapor deposition.

37. The method of claim 33, wherein preferentially reacting comprises atomic layer deposition.

38. The method of claim 34, wherein the chemical treatment gas is selected from the group consisting of

39. The method of claim 33, wherein the protective layer comprises adsorbed treatment chemical having a thickness no more than about two molecular monolayers.

40. The method of claim 33, wherein the protective layer defines a hydrophobic outer surface.

41. The method of claim 33, further comprising contacting the reaction space surface with a pre-treatment chemical, thereby densifying a plurality of reactive sites on the reaction space surface, prior to contacting the reaction space surface with the treatment chemical.

42. The method of claim 40, wherein the pre-treatment chemical comprises an oxidizing chemical.

43. The method of claim 33, wherein contacting the reaction space surface with the treatment chemical comprises an in situ exposure to a gas form of the treatment chemical.

44. A treated component of an atomic layer deposition (ALD) reactor that forms a portion of a reaction surface, the component comprising a portion of a surface having a protective layer thereon, the protective layer comprising an adsorbed treatment chemical having a thickness of less than about 5 molecular monolayers, the protective layer configured to inhibit reaction with ALD deposition reactants.

46. The method of claim 44, wherein applying the treatment chemical comprises ex situ exposure of reactor components to the treatment chemical.

47. The method of claim 44, wherein ex situ exposure comprises dipping the reactor components into a liquid mixture including the treatment chemical.

48. The method of claim 44, further comprising assembling the treated reactor components to form the reaction space.

49. The method of claim 44, wherein each cycle further comprises introducing a third reactant to the reaction space and removing excess third reactant from the reaction space.

50. The method of claim 44, wherein applying the treatment chemical comprises introducing a gas phase of the treatment chemical into the reaction space prior to loading the substrate into the reaction space.

51. The method of claim 44, further comprising re-treating the portions of the reaction space after a predetermined number of substrates have been processed sequentially in the reaction space.

52. The method of claim 44, further comprising re-treating the portions of the reaction space after a predetermined duration of deposition reactions has lapsed.

53. The method of claim 44, wherein applying the treatment chemical comprises a pre-treatment reaction to prepare the portions of the reaction space for the treatment chemical.

54. The method of claim 53, wherein the pre-treatment reaction comprises exposing the portions of the reaction space to an oxidizing agent.

55. The method of claim 54, wherein the oxidizing agent comprises ozone.

56. The method of claim 53, wherein the portions of the reaction space are exposed to the pre-treatment reaction prior to applying the treatment chemical.

57. The method of claim 44, wherein the treatment chemical comprises octadecyltrichlorosilane.

45. A method of deposition with reduced coating on portions of a reaction space, the method comprising:

applying a treatment chemical to one or more portions of the reaction space;

loading a substrate into the reaction space;

conducting a plurality of cycles of atomic layer deposition reactions, each cycle comprising;

introducing a first reactant into the reaction space, at least a portion of the first reactant adsorbing on the substrate,

removing excess first reactant from the reaction space,

introducing a second reactant gas into the reaction space, and

forming a first monolayer of a material on the surface of the substrate from the second reactant gas and the adsorbed portion of the first reactant gas;

removing excess second reactant from the reaction space;

removing the substrate from the reactor

wherein the treatment chemical deactivates the portion of the reaction space to the atomic layer deposition reactions.