Selective deposition of silicon-containing films
View Patent ↗Chemical vapor deposition methods use trisilane and a halogen-containing etchant source (such as chlorine) to selectively deposit Si-containing films over selected regions of mixed substrates. Dopant sources may be intermixed with the trisilane and the etchant source to selectively deposit doped Si-containing films. The selective deposition methods are useful in a variety of applications, such as semiconductor manufacturing.
1. A method of selective deposition of a silicon-containing layer over a substrate, comprising:
providing a substrate, the substrate comprising a first surface having a first surface morphology and a second surface having a second surface morphology different from the first surface morphology on the same side of the wafer, wherein the first surface comprises a semiconductor material and the second surface comprises a dielectric material;
intermixing trisilane and chlorine gas to thereby form an intermixed feed gas;
introducing the intermixed feed gas to the substrate under chemical vapor deposition conditions, wherein the chemical vapor deposition conditions comprise a pressure in the range of about 0.25 Torr to about 100 Torr; and
selectively depositing a Si-containing layer onto the first surface without depositing on the second surface by said introducing of the intermixed feed gas comprising trisilane and chlorine, wherein selectively depositing the Si-containing layer takes place at a deposition rate of greater than about 5 nm/min.
2. The method of claim 1 , wherein the chemical vapor deposition conditions comprise a temperature in the range of about 450° C. to about 700° C.
3. The method of claim 1 , wherein the chemical vapor deposition conditions comprise a temperature in the range of about 500° C. to about 650° C.
4. The method of claim 1 , wherein intermixing the trisilane and chlorine gas comprises flowing about 10 g/min to about 200 g/min of trisilane.
5. The method of claim 4 , wherein intermixing the trisilane and chlorine gas comprises flowing about 20 sccm to about 200 sccm of chlorine.
6. The method of claim 1 , wherein at least a part of the intennixing to form the intermixed feed gas is conducted within the chamber.
7. The method of claim 1 , further comprising intermixing a dopant gas to form the intermixed feed gas.
8. The method of claim 7 , wherein the dopant gas comprises at least one of a carbon source, a germanium source, an n-type dopant, and a p-type dopant.
9. The method of claim 8 , wherein the dopant gas comprises at least two of the carbon source, the germanium source, the n-type dopant, and the p-type dopant.
10. The method of claim 8 , wherein the dopant gas comprises a carbon source selected from the group consisting of monosilylmethane, disilylmethane, trisilylmethane, tetrasilylmethane, monomethyl silane, dimethyl silane and 1,3-disilabutane.
11. The method of claim 10 , wherein the carbon source comprises monomethyl silane.
12. The method of claim 8 , wherein the dopant gas comprises a carbon source, the carbon source comprising a chlorosilylmethane of the formula (SiH 3-z Cl z ) x CH 4-x-y Cl y , where x is an integer in the range of 1 to 4 and where y and z are each independently zero or an integer in the range of 1 to 3, with the provisos that x+y≦4 and at least one of y and z is not zero.
13. The method of claim 8 , wherein the dopant gas comprises a carbon source, the carbon source comprising an alkylhalosilane of the formula X a SiH b (C n H 2n+1 ) 4-a-b , where X is a halogen; n is 1 or 2; a is 1 or 2; b is 0, 1 or 2; and the sum of a and b is less than 4.
14. The method of claim 8 , wherein the dopant gas comprises an n-type dopant selected from the group consisting of arsine and phosphine.
15. The method of claim 8 , wherein the dopant gas comprises a germanium source selected from the group consisting of germane and digermane.
16. The method of claim 8 , wherein the dopant gas comprises a p-type dopant.
17. The method of claim 16 , wherein the dopant gas comprises diborane.
18. The method of claim 8 , wherein the Si-containing layer comprises an in situ doped silicon film.
19. The method of claim 18 , wherein the dopant gas comprises diborane, phosphine or arsine.
20. The method of claim 7 , wherein the dopant gas comprises an electrical dopant hydride that getters chlorine from a deposition surface during deposition.
21. The method of claim 1 , wherein the first surface morphology is single crystalline.
22. The method of claim 1 , wherein the first surface comprises a source and drain region of a partially fabricated transistor.
23. The method of claim 22 , wherein the first surface is recessed relative to a channel surface of the partially fabricated transistor.
24. The method of claim 23 , wherein the Si-containing layer comprises an alloy configured to introduce stress into a channel region of the partially fabricated transistor to improve electrical carrier mobility.
25. The method of claim 24 , wherein the Si-containing layer introduces tensile strain into the channel region.
26. The method of claim 24 , wherein the Si-containing layer introduces compressive strain into the channel region.
27. The method of claim 22 , wherein the Si-containing layer defines an elevated source/drain structure.
28. The method of claim 1 , wherein the Si-containing layer comprises a heteroepitaxial film.
29. The method of claim 1 , wherein the Si-containing layer has an average thickness between about 50 Å and about 1000 Å.
30. The method of claim 1 , further comprising intermixing a carrier gas to form the intermixed feed gas.
31. The method of claim 30 , wherein the carrier gas is a non-hydrogen inert gas.
32. The method of claim 31 , wherein no HCl is provided to the chamber while selectively depositing.
33. The method of claim 1 , further comprising introducing a non-hydrogen carrier gas comprising nitrogen gas with the intermixed feed gas to the substrate.
34. The method of claim 1 , further comprising intermixing an n-type dopant in situ to form the intermixed feed gas.