Method of making a high quality thin dielectric layer
View Patent ↗A method of making a high quality thin dielectric layer includes annealing a substrate and a base oxide layer overlying a top surface of the substrate at a first temperature in a first ambient and annealing the substrate and base oxide layer at a second temperature in a second ambient subsequent to the first anneal. The first ambient includes an inert gas ambient selected from the group consisting of a nitrogen, argon, and helium ambient. Prior to the first anneal, the base oxide layer has an initial thickness and an initial density. The first anneal causes a first density and thickness change in the base oxide layer from the initial thickness and density to a first thickness and density, with no incorporation of nitrogen, argon, or helium of the ambient within the base oxide layer. The first thickness is less than the initial thickness and the first density is greater than the initial density. The second anneal causes a second density and thickness change in the base oxide layer from the first thickness and density to a second thickness and density. The second thickness is larger than the first thickness and the second density is on the order of the greater than or equal to the first density.
1. A method of making a high quality thin dielectric layer, comprising:
annealing a substrate at a first temperature in a first ambient, the first ambient including an inert gas ambient selected from the group consisting of a nitrogen, argon, and helium ambient, and the substrate having a base oxide layer overlying a top surface of the substrate, the base oxide layer having an initial thickness and an initial density, wherein the first anneal causes a first density and thickness change in the base oxide layer from the initial thickness and density to a first thickness and density, with no incorporation of nitrogen, argon, or helium of the ambient within the base oxide layer, the first thickness being less than the initial thickness and the first density being greater than the initial density; and
annealing the substrate and base oxide layer at a second temperature in a second ambient subsequent to the first anneal, wherein the second anneal causes a second density and thickness change in the base oxide layer from the first thickness and density to a second thickness and density, the second thickness being larger than the first thickness and the second density being on the order of the greater than or equal to the first density.
2. The method of claim 1 , wherein the first ambient comprises a nitrogen ambient, and wherein the first anneal causes densification of the base oxide layer with no incorporation of nitrogen within the base oxide layer.
3. The method of claim 1 , wherein the first thickness change is on the order of up to fifty percent (50%) of the initial thickness and the first density change is on the order of up to double the initial density.
4. The method of claim 1 , wherein the first thickness change is approximately fifty percent (50%) of the initial thickness and the first density change is approximately double the initial density.
5. The method of claim 1 , wherein the base oxide layer includes one selected from the group consisting of a chemical oxide, a thermal oxide, a rapid thermal oxide, and a pretreatment oxide.
6. The method of claim 1 , wherein the first anneal includes a high temperature anneal and the first temperature comprises a temperature in the range of 900–1000° C.
7. The method of claim 6 , further wherein the first anneal includes a time duration on the order of 10–20 seconds.
8. The method of claim 1 , wherein the first anneal includes one selected from the group consisting of a rapid thermal anneal and a furnace anneal.
9. The method of claim 1 , wherein the second thickness change is on the order of up to or greater than one hundred percent (100%) of the first thickness.
10. The method of claim 1 , wherein the second density is on the order of greater than or equal to double the initial density.
11. The method of claim 1 , further wherein the first anneal reduces defects in the base oxide layer to improve a quality of the base oxide layer.
12. The method of claim 1 , further wherein the second anneal further substantially reduces defects in the base oxide layer to further improve a quality of the base oxide layer.
13. The method of claim 1 , wherein the second ambient includes a dilute oxygen ambient.
14. The method of claim 13 , further wherein the dilute oxygen ambient includes a mixture of oxygen and an inert gas.
15. The method of claim 14 , wherein the inert gas includes one selected from the group consisting of nitrogen, argon, and helium.
16. The method of claim 13 , further wherein the dilute oxygen ambient includes a volume mixture on the order of twenty-five percent (25%) oxygen and seventy-five percent (75%) inert gas.
17. The method of claim 1 , wherein the second anneal includes a high temperature anneal and the second temperature comprises a temperature above 800° C.
18. The method of claim 17 , further wherein the second temperature is approximately 900° C.
19. The method of claim 17 , further wherein the second anneal includes a time duration on the order of 10–20 seconds.
20. The method of claim 1 , wherein the second anneal includes one selected from the group consisting of a rapid thermal anneal tool anneal and a furnace anneal.
21. The method of claim 1 , wherein the substrate includes one selected from the group consisting of a bulk substrate and a semiconductor on insulator substrate.
22. The method of claim 21 , wherein the substrate further includes one selected from the group consisting of silicon, silicon germanium, and germanium.
23. The method of claim 1 , wherein the initial thickness is on the order of approximately 10–11 angstroms (Å), the first thickness is on the order of approximately 6–7 angstroms (Å), and the second thickness is on the order of approximately 8–12 angstroms (Å).
24. The method of claim 1 , further comprising:
forming a second dielectric layer overlying the base oxide layer, wherein the second dielectric layer and base oxide layer comprise a dielectric stack.
25. The method of claim 24 , wherein forming the second dielectric layer includes forming one selected from the group consisting of a oxide, nitride, oxynitride, and high-k dielectric layer.
26. The method of claim 24 , wherein forming the second dielectric layer overlying the base oxide layer includes nitridation.
27. The method of claim 24 , wherein forming the second dielectric layer overlying the base oxide layer includes atomic layer deposition of an oxide.
28. The method of claim 27 , wherein the oxide includes a metal oxide.
29. A semiconductor device including a high quality thin dielectric layer formed by the method of claim 24 .
30. An integrated circuit including a semiconductor device having a high quality thin dielectric layer formed by the method of claim 24 .
31. A semiconductor device including a high quality thin dielectric layer formed by the method of claim 1 .
32. An integrated circuit including a semiconductor device having a high quality thin dielectric layer formed by the method of claim 1 .
33. A method of making a high quality thin dielectric layer, comprising:
annealing a substrate at a first temperature in a first ambient, the substrate having a base oxide layer overlying a top surface of the substrate, the base oxide layer having an initial thickness and an initial density, wherein the first anneal causes a density and thickness change in the base oxide layer from the initial thickness and density to a first thickness and density, with no incorporation of a component of the ambient within the base oxide layer, the first thickness being less than the initial thickness and the first density being greater than the initial density, wherein the first ambient comprises a nitrogen ambient, the first anneal causes a densification of the base oxide layer with no incorporation of nitrogen within the base oxide layer, the thickness change is on the order of fifty percent (50%), and the density change is on the order of double the initial density; and
annealing the substrate and base oxide layer at a second temperature in a second ambient subsequent to the first anneal, wherein the second anneal causes a second density and thickness change in the base oxide layer from the first thickness and density to a second thickness and density, the second thickness being larger than the first thickness and the second density being on the order of the greater than or equal to the first density, wherein the second ambient comprises a dilute oxygen ambient.