Surface modification layer for conductive feature formation
Embodiments described herein relate generally to methods for forming a conductive feature in a dielectric layer in semiconductor processing and structures formed thereby. In some embodiments, a structure includes a dielectric layer over a substrate, a surface modification layer, and a conductive feature. The dielectric layer has a sidewall. The surface modification layer is along the sidewall, and the surface modification layer includes phosphorous and carbon. The conductive feature is along the surface modification layer.
1. A method of manufacturing a semiconductor device, the method comprising:
depositing a dielectric layer over a conductive region over a semiconductor substrate;
forming an opening through the dielectric layer to expose the conductive region;
treating exposed portions of the dielectric layer with a self-limiting reaction to form a monolayer of material, wherein the self-limiting reaction deposits a phosphoric acid derivative material as part of the monolayer of material; and
depositing conductive material within the opening.
2. The method of claim 1 , wherein the treating the exposed portions of the dielectric layer is performed at least in part with a wet process.
3. The method of claim 2 , wherein the wet process comprises applying a solution, the solution comprising a phosphoric acid derivative and an organic solvent.
4. The method of claim 3 , wherein the organic solvent comprises ethylene glycol.
5. The method of claim 3 , wherein the phosphoric acid derivative comprises Di-(2-ethylhexyl)phosphoric acid or dihexylphosphoric acid.
6. The method of claim 3 , wherein the phosphoric acid derivative comprises ethyl hexadecyl phosphate or n-Butyl-octyl-hydrogenphosphate.
7. A method of manufacturing a semiconductor device, the method comprising:
forming an opening through a dielectric layer to expose an underlying conductive region;
replenishing carbon at a surface of the dielectric layer by applying a phosphoric acid derivative to the surface of the dielectric layer; and
filling the opening with a conductive material.
8. The method of claim 7 , wherein the replenishing the carbon is performed at least in part with a dry process.
9. The method of claim 8 , wherein the dry process flows a phosphoric acid derivative gas over the surface of the dielectric layer.
10. The method of claim 9 , wherein the phosphoric acid derivative gas comprises diisoamylphosphoric acid or ethyl octyl phosphate.
11. The method of claim 9 , wherein the phosphoric acid derivative gas is flowed at a flow rate of between 1 sccm and wo sccm.
12. The method of claim 11 , wherein the dry process is performed at a pressure of between 10 mTorr and 1 Torr.
13. The method of claim 12 , wherein the dry process is performed at a temperature of between 20° C. and wo ° C.
14. The method of claim 8 , wherein the dry process is performed without using a plasma.
15. A method of manufacturing a semiconductor device, the method comprising:
forming an opening through a dielectric layer to expose an underlying conductive region; and
replacing OH groups on a surface of the dielectric layer with a monolayer comprising phosphoric acid derivative molecules, the monolayer having a thickness no thicker than a length of one of the phosphoric acid derivative molecules.
16. The method of claim 15 , wherein the replacing the OH groups on the surface of the dielectric layer comprises applying a solution, the solution comprising the phosphoric acid derivative molecules.
17. The method of claim 15 , wherein the replacing the OH groups on the surface of the dielectric layer comprising flowing a gas over the surface of the dielectric layer.
18. The method of claim 17 , wherein the flowing the gas over the surface of the dielectric layer is performed without a plasma.
19. The method of claim 15 , wherein the opening has an aspect ratio in a range from 3 to 6.
20. The method of claim 15 , wherein the replacing the OH groups on the surface of the dielectric layer is performed as part of a middle end of line process.