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 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% in an entirety of the process for selectively forming AlN.
2. The process of claim 1 , wherein the one or more super-cycles are repeated until an AlN thin film of a desired thickness is formed on the first surface of the substrate.
3. The process of claim 1 , the one or more super-cycles additionally comprising exposing the substrate to a pretreatment reactant.
4. The process of claim 3 , wherein the substrate is exposed to a pretreatment reactant prior to the one or more selective deposition sub-cycles.
5. The process of claim 3 , wherein the pretreatment reactant comprises plasma.
6. The process of claim 5 , wherein the plasma is generated from a gas comprising H 2 .
7. 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.
8. The process of claim 7 , wherein AlN is deposited on the first surface of the substrate relative to the second surface of the substrate with a selectivity of greater than 5% in the one or more selective deposition sub-cycles.
9. The process of claim 7 , wherein the one or more selective deposition sub-cycles are repeated until the one or more selective deposition sub-cycles are no longer selective.
10. The process of claim 7 , wherein the first vapor phase precursor comprising aluminum comprises tritertbutylaluminum (TTBA), trimethylaluminum (TMA) or triethylaluminum (TEA).
11. The process of claim 7 , wherein the second vapor phase precursor comprising nitrogen comprises NH 3 .
12. 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.
13. The process of claim 12 , wherein the first vapor phase halide etch reactant comprises NF 3 or NbF 5 .
14. The process of claim 12 , wherein the second vapor phase etch reactant comprising aluminum comprises trimethylaluminum (TMA) or triethylaluminum (TEA).
15. The process of claim 12 , wherein the one or more thermal etching sub-cycles are carried out at a process temperature of about 300° C.
16. The process of claim 1 , wherein the first surface is a conductive surface and the second different surface is a dielectric surface.
17. The process of claim 1 , wherein the first surface comprises W and the second surface comprises SiO 2 .
18. The process of claim 1 , wherein the first surface comprises TiN and the second surface comprises SiO 2 .
19. The process of claim 1 , wherein the one or more selective deposition sub-cycles are repeated from 1 to about 300 times and the one or more thermal etching sub-cycles are repeated from 1 to about 150 times.
20. 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 trimethylaluminum (TMA) and contacting the substrate with a second vapor phase precursor comprising NH 3 , and the one or more thermal etching sub-cycles comprise contacting the substrate with a first vapor phase halide etch reactant comprising NF 3 , and a second vapor phase etch reactant comprising TMA.