Silicon germanium selective oxidation process
Implementations described herein relate to selective oxidation processes for semiconductor device manufacturing. In one implementation, the process includes delivering a substrate having a semiconductor device comprising at least a silicon material and a silicon germanium material formed thereon to a process chamber. Process variables are determined based upon the germanium concentration of the silicon germanium material and a desired oxide thickness and a selective oxidation process is performed utilizing the determined process variables.
1. A selective oxidation method, comprising:
pressurizing a process chamber to greater than about 500 Torr;
heating a process region of the process chamber to a temperature less than about 700° C.;
generating reactive species comprising hydrogen and oxygen in the process region; and
exposing a substrate comprising at least a silicon material and a silicon germanium material to the reactive species to selectively oxidize the silicon germanium material preferentially to the silicon material, wherein the selectively oxidizing the silicon germanium comprises forming a germanium oxide/crystalline germanium superlattice structure.
2. The method of claim 1 , wherein the silicon material and the silicon germanium material are simultaneously exposed to the reactive species.
3. The method of claim 2 , wherein the silicon germanium material is selectively oxidized at a rate of between 2 times and 16 times greater than an oxidation rate of the silicon material.
4. The method of claim 1 , wherein the reactive species are hydroxyl radicals.
5. The method of claim 1 , wherein the reactive species are hydroxide ions.
6. The method of claim 1 , wherein the reactive species are hydrogen and oxygen radicals.
7. The method of claim 1 , wherein the reactive species are hydrogen and oxygen ions.
8. The method of claim 1 , wherein a ratio of oxygen to hydrogen is between 19:1 and 1:9.
9. The method of claim 1 , further comprising:
generating hydroxyl radicals remotely from the process chamber and delivering the hydroxyl radicals to the process region.
10. The method of claim 1 , further comprising:
generating hydrogen and oxygen radicals remotely from the process chamber and delivering the hydrogen and oxygen radicals to the process region.
11. A selective oxidation method, comprising:
pressurizing a process chamber between 7 Torr and 550 Torr;
heating a process region of the process chamber to a temperature less than about 700° C. but greater than about 575° C.;
generating reactive species comprising hydrogen and oxygen in the process region; and
exposing a substrate comprising at least a silicon material and a silicon germanium material to the reactive species to selectively oxidize the silicon germanium material preferentially to the silicon material, wherein the selectively oxidizing the silicon germanium comprises forming a germanium oxide/crystalline germanium superlattice structure.
12. The method of claim 11 , wherein the silicon material and the silicon germanium material are simultaneously exposed to the reactive species.
13. The method of claim 12 , wherein the silicon germanium material is selectively oxidized at a rate between 2 times and 16 times greater than an oxidation rate of the silicon material.
14. The method of claim 11 , wherein the reactive species are hydroxyl radicals.
15. The method of claim 11 , wherein a ratio of oxygen to hydrogen is between 19:1 and 1:9.
16. The method of claim 11 , further comprising:
generating hydroxyl radicals remotely from the process chamber and delivering the hydroxyl radicals to the process region.
17. A selective oxidation method, comprising:
pressurizing a process chamber to greater than about 500 Torr;
heating a process region of the process chamber to a temperature less than about 700° C.;
generating reactive species comprising hydrogen and oxygen in the process region, wherein a ratio of oxygen to hydrogen is between 19:1 and 1:9;
generating hydroxyl radicals remotely from the process chamber and delivering the hydroxyl radicals to the process region; and
exposing a substrate comprising at least a silicon material and a silicon germanium material to the reactive species to selectively oxidize the silicon germanium material preferentially to the silicon material, wherein the silicon germanium is oxidized at a rate of between 2 times and 16 times greater than an oxidation rate of the silicon material, and wherein the selectively oxidizing the silicon germanium comprises forming a germanium oxide/crystalline germanium superlattice structure.
18. The method of claim 17 , wherein the silicon material and the silicon germanium material are simultaneously exposed to the reactive species and hydroxyl radicals.