Methods of selective deposition of heavily doped epitaxial SiGe
The invention generally teaches a method for depositing a silicon film or silicon germanium film on a substrate comprising placing the substrate within a process chamber and heating the substrate surface to a temperature in the range from about 600° C. to about 900° C. while maintaining a pressure in the range from about 0.1 Torr to about 200 Torr. A deposition gas is provided to the process chamber and includes SiH 4 , an optional germanium source gas, an etchant, a carrier gas and optionally at least one dopant gas. The silicon film or the silicon germanium film is selectively and epitaxially grown on the substrate. One embodiment teaches a method for depositing a silicon-containing film with an inert gas as the carrier gas. Methods may include the fabrication of electronic devices utilizing selective silicon germanium epitaxial films.
1. A method for depositing a silicon germanium film on a substrate comprising:
providing a substrate within a process chamber;
heating the substrate to a temperature within a range from about 500° C. to about 900° C.;
exposing the substrate to a first deposition gas comprising silane, germanium, a carbon source, hydrogen chloride, a carrier gas, and at least one dopant gas to epitaxially and selectively deposit a first silicon germanium material on the substrate, wherein the first silicon germanium material contains a dopant concentration of about 2.5×10 21 atoms/cm 3 ; and
exposing the substrate to a second deposition gas comprising dichlorosilane and a germanium source to epitaxially and selectively deposit a second silicon germanium material on the substrate.
2. The method of claim 1 , wherein the at least one dopant gas is a boron containing compound selected from the group consisting of borane, diborane, triborane, trimethylborane, triethylborane, and derivatives thereof.
3. The method of claim 2 , wherein the first silicon germanium material contains a boron concentration of about 2.5×10 21 atoms/cm 3 .
4. The method of claim 3 , wherein the carbon source is an organosilane.
5. The method of claim 4 , wherein the carbon source is methylsilane.
6. The method of claim 1 , wherein the at least one dopant gas includes an arsenic containing compound or a phosphorus containing compound.
7. The method of claim 1 , wherein the carrier gas is selected from the group consisting of hydrogen, argon, nitrogen, helium, and combinations thereof.
8. The method of claim 7 , wherein the first deposition gas further comprises dichlorosilane.
9. The method of claim 7 , wherein the temperature is within a range from about 600° C. to about 750° C. and the process chamber is at a pressure within a range from about 0.1 Torr to about 200 Torr.
10. The method of claim 7 , wherein the silicon germanium film has a thickness within a range from about 100 Å to about 3,000 Å.
11. The method of claim 10 , wherein the silicon germanium film is deposited within a device used for CMOS, Bipolar, or BiCMOS application.
12. The method of claim 11 , wherein the silicon germanium film is deposited during a fabrication step selected from the group consisting of contact plug, source/drain extension, elevated source/drain, and bipolar transistor.
13. The method of claim 1 , wherein a silicon-containing material is deposited on the substrate before the first silicon germanium material.
14. The method of claim 13 , wherein the silicon-containing material is deposited by a deposition process comprising dichlorosilane.
15. A selective epitaxial method for depositing a silicon germanium film on a substrate comprising:
placing a substrate within a process chamber;
heating the substrate to a temperature within a range from about 500° C. to about 900° C.; and
exposing the substrate to a deposition gas comprising silane, a germanium source, a carbon source, an etchant source, a carrier gas, and at least one dopant gas to epitaxially and selectively form a silicon germanium material containing a dopant concentration of about 2.5×10 21 atoms/cm 3 .
16. The method of claim 15 , wherein the germanium source is selected from the group consisting of germane, digermane, trigermane, tetragermane, and derivatives thereof.
17. The method of claim 16 , wherein the carrier gas is selected from the group consisting of hydrogen, argon, nitrogen, helium, and combinations thereof.
18. The method of claim 17 , wherein the temperature is within a range from about 600° C. to about 750° C. and the process chamber is at a pressure within a range from about 0.1 Torr to about 200 Torr.
19. The method of claim 18 , wherein the etchant source is selected from the group consisting of hydrogen chloride, tetrachlorosilane, tetrachloromethane, dichloromethane, chlorine, derivatives thereof, and combinations thereof.
20. The method of claim 15 , wherein the at least one dopant gas is a boron containing compound selected from the group consisting of borane, diborane, triborane, trimethylborane, triethylborane, and derivatives thereof.
21. The method of claim 20 , wherein the carbon source is an organosilane.
22. The method of claim 21 , wherein the carbon source is methylsilane.
23. The method of claim 15 , wherein the at least one dopant gas is selected from the group consisting of an arsenic containing compound and a phosphorus containing compound.
24. The method of claim 15 , wherein the deposition gas further comprises dichlorosilane.
25. The method of claim 18 , wherein the silicon germanium film has a thickness within a range from about 100 Å to about 3,000 Å.
26. The method of claim 25 , wherein the silicon germanium film is deposited within a device used for CMOS, Bipolar, or BiCMOS application.
27. The method of claim 26 , wherein the silicon germanium film is deposited during a fabrication step selected from the group consisting of contact plug, source/drain extension, elevated source/drain, and bipolar transistor.
28. The method of claim 15 , wherein the silicon germanium material is deposited having a first thickness, thereafter, the silane is replaced by dichlorosilane, and a second silicon germanium material is epitaxially and selectively deposited having a second thickness on the silicon germanium material.
29. The method of claim 15 , wherein a silicon-containing material is deposited on the substrate before the silicon germanium material.
30. The method of claim 29 , wherein the silicon-containing material is deposited by a deposition process comprising dichlorosilane.
31. A method for depositing a silicon germanium film on a substrate comprising:
placing a substrate within a process chamber;
heating the substrate to a temperature within a range from about 500° C. to about 900° C.; and
exposing the substrate to a deposition gas comprising a silicon-containing gas, a germanium source, a carbon source, hydrogen chloride, and a boron-containing dopant gas to epitaxially and selectively deposit a silicon germanium material on the substrate, wherein the silicon germanium material contains a boron concentration of about 2.5×10 21 atoms/cm 3 .
32. A method for depositing a silicon germanium film on a substrate comprising:
placing a substrate within a process chamber;
exposing the substrate to a first deposition gas comprising silane, a first germanium source, a carbon source, hydrogen chloride, and a carrier gas to epitaxially deposit a first silicon germanium containing material having a first thickness on the substrate and containing a dopant concentration of about 2.5×10 21 atoms/cm 3 ; and
exposing the substrate to a second deposition gas comprising dichlorosilane and a second germanium source to epitaxially deposit a second silicon germanium containing material having a second thickness on the first silicon germanium containing material.
33. The method of claim 32 , wherein the first silicon germanium containing material is selectively deposited on the substrate.
34. The method of claim 33 , wherein the first deposition gas further comprises at least one dopant gas.
35. The method of claim 34 , wherein the at least one dopant gas comprises an element selected from the group consisting boron, arsenic, phosphorus, and combinations thereof.
36. The method of claim 35 , wherein the at least one dopant gas comprises a boron containing compound selected from the group consisting of borane, diborane, triborane, trimethylborane, triethylborane, and derivatives thereof.
37. The method of claim 36 , wherein the carbon source is an organosilane.
38. The method of claim 37 , wherein the carbon source is methylsilane.
39. The method of claim 33 , wherein the second silicon germanium containing material is selectively deposited on the substrate.
40. The method of claim 39 , wherein the second deposition gas further comprises hydrogen chloride and at least one dopant gas.
41. The method of claim 40 , wherein the at least one dopant gas comprises an element selected from the group consisting boron, arsenic, phosphorus, and combinations thereof.
42. The method of claim 41 , wherein the at least one dopant gas comprises a boron containing compound selected from the group consisting of borane, diborane, triborane, trimethylborane, triethylborane, and derivatives thereof.
43. The method of claim 33 , wherein the first and second germanium sources are independently selected from the group consisting of germane, digermane, trigermane, tetragermane, and derivatives thereof.
44. The method of claim 43 , wherein the first and second thicknesses are independently within a range from about 100 Å to about 3,000 Å.
45. The method of claim 44 , wherein the substrate is heated to a first temperature during the exposure of the first deposition gas and to a second temperature during the exposure of the second deposition gas, wherein the first and second temperatures are independently a temperature within a range from about 500° C. to about 900° C.