Etchant treatment processes for substrate surfaces and chamber surfaces
In one embodiment of the invention, a method for finishing or treating a silicon-containing surface is provided which includes removing contaminants and/or smoothing the surface contained on the surface by a slow etch process (e.g., about <100 Å/min). The silicon-containing surface is exposed to an etching gas that contains an etchant and a silicon source. Preferably, the etchant is chlorine gas so that a relatively low temperature (e.g., <800° C.) is used during the process. In another embodiment, a method for etching a silicon-containing surface during a fast etch process (e.g., about >100 Å/min) is provided which includes removing silicon-containing material to form a recess in a source/drain (S/D) area on the substrate. In another embodiment, a method for cleaning a process chamber is provided which includes exposing the interior surfaces with a chamber clean gas that contains an etchant and a silicon source. The chamber clean process limits the etching of quartz and metal surfaces within the process chamber.
1. A method for forming a silicon-containing material on a substrate surface, comprising:
positioning a substrate comprising a silicon material containing a contaminant within a process chamber;
exposing the substrate to an etching gas comprising chlorine gas and a silicon source at a temperature of less than about 800° C. during an etching process to remove the contaminant;
exposing the substrate to a deposition gas during a deposition process; and
exposing the process chamber to a chamber clean gas comprising the chlorine gas and the silicon source during a chamber clean process.
2. The method of claim 1 , wherein the substrate is removed from the process chamber prior to starting the chamber clean process.
3. The method of claim 2 , wherein the silicon source comprises a reagent selected from the group consisting of silane, disilane, chlorosilane, dichlorosilane, trichlorosilane, hexachlorodisilane, derivatives thereof, and combinations thereof.
4. The method of claim 3 , wherein the chamber clean gas further comprises a carrier gas selected from the group consisting of nitrogen, hydrogen, argon, helium, forming gas, and combinations thereof.
5. The method of claim 4 , wherein the silicon source comprises silane and the carrier gas comprises nitrogen.
6. The method of claim 3 , wherein the process chamber is heated to a temperature of about 600° C. or higher during the chamber clean process.
7. The method of chamber clean process claim 6 , wherein the temperature of the process chamber during the is within a range from about 700° C. to about 900° C. and the process chamber is at a pressure of about 760 Torr or less.
8. The method of claim 1 , wherein the silicon material further contains a rough surface prior to the etching process, wherein the rough surface has a roughness of greater than 1 nm RMS.
9. The method of claim 8 , wherein the rough surface is removed during the etching process to form a smooth surface having a roughness of about 1 nm RMS or less.
10. The method of claim 2 , wherein the deposition gas comprises the chlorine gas and the silicon source, and the deposition process is an epitaxy deposition process.
11. The method of claim 2 , wherein the etching gas, the deposition gas, and the chamber clean gas each comprises silane and chlorine gas.
12. A method for forming a silicon-containing material on a substrate surface, comprising:
positioning a substrate comprising a silicon material containing a contaminant within a process chamber;
exposing the substrate to an etching gas comprising a silicon source at a temperature of less than about 800° C. during an etching process to remove the contaminant; and
exposing the process chamber to a chamber clean gas comprising chlorine gas and the silicon source during a chamber clean process.
13. The method of claim 12 , wherein the substrate is removed from the process chamber prior to starting the chamber clean process.
14. The method of claim 12 , wherein the chamber clean gas further comprises nitrogen, the silicon source comprises silane, and the process chamber is heated to a temperature of about 600 20 C. or higher during the chamber clean process.
15. The method of claim 12 , wherein the temperature of the process chamber during the chamber clean process is within a range from about 700° C. to about 900° C. and the process chamber is at a pressure of about 760 Torr or less.
16. The method of claim 12 , further comprising exposing the silicon material to a deposition gas comprising the silicon source during a deposition process subsequent to the etching process and prior to the chamber clean process.
17. The method of claim 16 , wherein the etchant gas comprises chlorine gas and the silicon material contains a smooth surface having a roughness of about 1 nm RMS or less after the etching process.
18. The method of claim 16 , wherein the deposition process is an epitaxy deposition process.
19. The method of claim 16 , wherein the etching gas, the deposition gas, and the chamber clean gas each comprises silane.
20. A method for forming a silicon-containing material on a substrate surface, comprising:
positioning a substrate comprising a silicon material containing a contaminant within a process chamber;
exposing the substrate to an etching gas comprising chlorine gas and a silicon source at a temperature of less than about 800° C. during an etching process to remove the contaminant;
exposing the substrate to a deposition gas comprising the silicon source during an epitaxial deposition process;
removing the substrate from the process chamber; and
exposing the process chamber to a chamber clean gas comprising an etchant gas and the silicon source during a chamber clean process.
21. The method of claim 20 , wherein the chamber clean gas comprises chlorine gas, and the silicon source comprises silane.
22. A method for forming a silicon-containing material on a substrate surface, comprising:
positioning a substrate comprising a silicon material containing a contaminant within a process chamber;
exposing the substrate to an etching gas comprising chlorine gas and silane at a temperature of less than about 800° C. during an etching process to remove the contaminant;
exposing the substrate to a deposition gas comprising the chlorine gas and the silane during an epitaxial deposition process;
removing the substrate from the process chamber; and
exposing the process chamber to a chamber clean gas comprising the chlorine gas and the silane during a chamber clean process.
23. The method of claim 22 , wherein the etching process removes material at a rate of about 10 Å/min or less.
24. The method of claim 23 , wherein the rate is about 2 Å/min or less.
25. The method of claim 22 , wherein the etching process removes material at a rate within a range from about 200 Å/min to about 1,000 Å/min.