Multi-step anneal of thin films for film densification and improved gap-fill
A method of annealing a substrate comprising a trench containing a dielectric material, the method including annealing the substrate at a first temperature of about 200° C. to about 800° C. in a first atmosphere comprising an oxygen containing gas, and annealing the substrate at a second temperature of about 800° C. to about 1400° C. in a second atmosphere lacking oxygen. In addition, a method of annealing a substrate comprising a trench containing a dielectric material, the method including annealing the substrate at a first temperature of about 400° C. to about 800° C. in the presence of an oxygen containing gas, purging the oxygen containing gas away from the substrate, and raising the substrate to a second temperature from about 900° C. to about 1100° C. to further anneal the substrate in an atmosphere that lacks oxygen.
1. A method of annealing a substrate comprising a trench containing a dielectric material, the method comprising:
forming the dielectric material on the substrate with chemical vapor deposition by reacting a silicon-containing process gas and an oxidizer-containing process gas, wherein a seam remains within the trench following the operation of forming the dielectric material;
annealing the substrate at a first temperature of about 200° C. to about 800° C. in a first atmosphere comprising an oxygen containing gas to heal the seam; and
annealing the substrate at a second temperature of about 800° C. to about 1400° C. in an inert, noble, or ammonia gas atmosphere lacking oxygen.
2. The method of claim 1 , wherein the oxygen containing gas comprises steam (H 2 O), nitric oxide (NO), or nitrous oxide (N 2 O).
3. The method of claim 1 , wherein the oxygen containing gas comprises in-situ generated steam (ISSG) produced from a combustion reaction of hydrogen (H2) and oxygen (O2) gas.
4. The method of claim 1 , wherein the first atmosphere comprises nitrogen (N2), hydrogen (H2), ammonia (NH3), helium (He), neon (Ne), Argon (Ar), krypton (Kr), or xenon (Xe).
5. The method of claim 1 , wherein the inert, noble, or ammonia gas atmosphere comprises nitrogen (N2), ammonia (NH3), helium (He), neon (Ne), Argon (Ar), krypton (Kr), or xenon (Xe).
6. The method of claim 1 , wherein the substrate is kept at the first temperature for about 30 minutes.
7. The method of claim 1 , wherein the substrate is kept at the second temperature for about 30 minutes.
8. The method of claim 1 , wherein the first temperature is about 600° C. to about 700° C.
9. The method of claim 1 , wherein the second temperature is about 1000° C. to about 1100° C.
10. The method of claim 1 , the method comprising:
purging the oxygen containing gas away from the substrate with a purge gas; and
raising the substrate from the first temperature to the second temperature at a rate of about 4° C./min or more.
11. The method of claim 10 , wherein the purge gas comprises the inert gas.
12. The method of claim 10 , wherein the oxygen containing gas is purged for about 60 minutes prior to the raising of the substrate to the second temperature.
13. The method of claim 1 , wherein the substrate is raised to the first temperature and the second temperature using a furnace or radiative heating chamber.
14. The method of claim 1 , wherein, prior to the annealing, a wet etch rate ratio of the dielectric material to thermal oxide is about 10:1 or more.
15. The method of claim 1 , wherein, after the annealing at the second temperature, a wet etch rate ratio of the dielectric material to thermal oxide is about 1.2:1 or less.
16. The method of claim 1 , wherein the dielectric material comprises silicon dioxide.
17. The method of claim 1 , wherein the dielectric material in the trench is deposited using a chemical vapor deposition or a spin-on-dielectric technique.
18. A method of annealing a substrate comprising a trench containing a dielectric material, the method comprising:
depositing the dielectric material in the trench using chemical vapor depositions, wherein a seam remains within the trench following the operation of forming the dielectric material;
annealing the substrate at a first temperature of about 400° C. to about 800° C. in the presence of an oxygen containing gas to heal the seam;
purging the oxygen containing gas away from the substrate; and
raising the substrate to a second temperature from about 900° C. to about 1100° C. to further anneal the substrate in an inert, noble, or ammonia gas atmosphere that lacks oxygen.
19. The method of claim 18 , wherein the oxygen containing gas comprises in-situ generated steam (ISSG) produced from a combustion reaction of hydrogen (H 2 ) and oxygen (O 2 ) gas.
20. The method of claim 18 , wherein the inert gas atmosphere comprises nitrogen (N 2 ).
21. The method of claim 18 , wherein the first temperature is about 800° C. and the second temperature is about 1050° C.
22. The method of claim 18 , wherein the substrate is maintained at the first temperature for about 30 minutes, the oxygen containing gas is purged away from the substrate for about 60 minutes, and the substrate is maintained at the second temperature for about 30 minutes.
23. The method of claim 1 , wherein the silicon-containing process gas comprises TEOS.
24. The method of claim 1 , wherein the oxidizer-containing process gas comprises ozone.
25. The method of claim 1 , wherein the chemical vapor deposition comprise sub-atmospheric chemical vapor deposition.
26. A method of forming and annealing a dielectric material in a substrate trench, the method comprising:
forming the dielectric material on the substrate with chemical vapor reacting tetraethoxysilane with ozone, wherein a seam remains within the trench following the operation of forming the dielectric material;
annealing the substrate at a first temperature of about 200° C. to about 800° C. in a first atmosphere comprising an oxygen containing gas to heal the seam; and
annealing the substrate at a second temperature of about 800° C. to about 1400° C. in an inert, noble, or ammonia gas atmosphere lacking oxygen.