Selective deposition of aluminum and nitrogen containing material
Methods are provided for selectively depositing Al and N containing material on a first conductive surface of a substrate relative to a second, dielectric surface of the same substrate. In some aspects, methods of forming an Al and N containing protective layer or etch stop layer for use in integrated circuit fabrication are provided.
1. A process for selectively forming AlN on a first surface of a substrate relative to a second different surface of the substrate, the process comprising one or more super-cycles comprising:
selectively depositing AlN on the first surface of the substrate relative to the second different surface of the substrate by one or more selective deposition sub-cycles;
etching the deposited AlN by one or more thermal etching sub-cycles;
wherein the super-cycle further comprises exposing the substrate to a pretreatment reactant prior to the selectively depositing AlN; and
wherein AlN is selectively formed on the first surface of the substrate relative to the second different surface of the substrate with a selectivity greater than about 99%.
2. The process of claim 1 , wherein in the one or more super-cycles the one or more selective deposition sub-cycles and the one or more thermal etching sub-cycles are repeated until an AlN thin film of a desired thickness has been formed on the first surface.
3. The process of claim 1 , wherein the pretreatment reactant comprises plasma.
4. The process of claim 3 , wherein the plasma is generated from a gas comprising H 2 .
5. The process of claim 1 , wherein the one or more selective deposition sub-cycles comprise:
contacting the substrate with a first vapor phase precursor comprising aluminum; and
contacting the substrate with a second vapor phase precursor comprising nitrogen.
6. The process of claim 5 , wherein the one or more selective deposition sub-cycles are repeated until AlN of a desired thickness is deposited on the first surface.
7. The process of claim 5 , wherein the one or more selective deposition sub-cycles are repeated until the one or more selective deposition sub-cycles are no longer selective.
8. The process of claim 5 , wherein the first vapor phase precursor comprising aluminum comprises one of tritertbutylaluminum (TTBA), trimethylaluminum (TMA) or triethylaluminum (TEA).
9. The process of claim 5 , wherein the second vapor phase precursor comprising nitrogen comprises NH 3 .
10. The process of claim 1 , wherein the one or more thermal etching sub-cycles comprise:
contacting the substrate with a first vapor phase halide etch reactant; and
contacting the substrate with a second vapor phase etch reactant comprising aluminum.
11. The process of claim 10 , wherein the first vapor phase halide etch reactant comprises NF 3 or NbF 5 .
12. The process of claim 10 , wherein the second vapor phase etch reactant comprising aluminum comprises trimethylaluminum (TMA) or triethylaluminum (TEA).
13. The process of claim 10 , wherein the one or more etching sub-cycles are carried out at a process temperature of about 300° C.
14. The process of claim 1 , wherein the first surface comprises W and the second surface comprises SiO 2 .
15. The process of claim 1 , wherein the first surface comprises TiN and the second surface comprises SiO 2 .
16. The process of claim 1 , wherein the one or more selective deposition sub-cycles are repeated from 1 to about 300 times; and
wherein the one or more thermal etching sub-cycles comprise an atomic layer etching (ALE) process and are repeated from 1 to about 150 times.
17. A process for selectively forming AlN on a first surface of a substrate relative to a second different surface of the same substrate, the process comprising a super-cycle comprising:
a selective deposition sub-cycle comprising:
alternately and sequentially contacting the substrate with a first vapor phase precursor comprising aluminum and a second vapor phase precursor comprising nitrogen such that the AlN is deposited on the first surface of the substrate relative to the second different surface of the same substrate with a selectivity greater than about 5%; and
an atomic layer etch sub-cycle comprising:
alternately and sequentially contacting the substrate with a first vapor phase halide etch reactant and a second vapor phase etch reactant comprising aluminum.
18. The process of claim 17 , wherein the super-cycle is repeated one or more times.
19. The process of claim 17 , the super-cycle further comprising exposing the substrate to a plasma generated from a gas comprising H 2 prior to the selective deposition sub-cycle.
20. The process of claim 17 , wherein the first vapor phase precursor comprising aluminum comprises trimethylaluminum (TMA), the second vapor phase precursor comprising nitrogen comprises NH 3 , the first vapor phase halide etch reactant comprises NF 3 , and the second vapor phase etch reactant comprising aluminum comprises TMA.
21. The process of claim 17 , wherein the first surface is a conductive surface and the second surface is a dielectric surface.