Method of selectively forming a conductive barrier layer by ALD
View Patent ↗By providing a surface modification process prior to or during a self-limiting deposition process, the per se highly conformal deposition behavior may be selectively changed so as to obtain reliable coverage at specific surface areas, while significantly reducing or suppressing a deposition above unwanted surface areas, such as the bottom of a via in advanced metallization structures of highly scaled semiconductor devices.
1. A method, comprising:
forming an opening in a metallization structure of a semiconductor device, said opening comprising a substantially horizontal surface and a substantially vertical surface;
forming an inhibitor material above said substantially horizontal surface of said opening, wherein forming said inhibitor material comprises performing a directional deposition process having a main deposition direction that is substantially perpendicular to said substantially horizontal surface; and
after forming said inhibitor material, forming a first layer of a liner material inside of said opening, wherein forming said first layer of said liner material comprises performing a self-limiting deposition process, and wherein said inhibitor material provides a reduced deposition rate on said substantially horizontal surface as compared to a deposition rate on said substantially vertical surface.
2. The method of claim 1 , wherein performing said directional deposition process comprises performing an ionized physical vapor deposition process.
3. The method of claim 1 , wherein performing said self-limiting deposition process comprises performing an atomic layer deposition process.
4. The method of claim 1 , wherein forming said opening comprises forming a via opening.
5. The method of claim 1 , wherein forming said opening comprises forming a trench opening.
6. The method of claim 1 , wherein forming said first layer of said liner material inside of said opening comprises depositing a material layer comprising tantalum nitride.
7. The method of claim 1 , further comprising forming a second layer of said liner material inside of said opening after forming said first layer of said liner material.
8. The method of claim 7 , wherein depositing said second layer of said liner material inside of said opening comprises depositing said second layer above said substantially horizontal surface and adjacent to said substantially vertical surface.
9. The method of claim 7 , wherein forming at least one of said first and second layers of said liner material comprises depositing a material layer comprising tantalum.
10. The method of claim 7 , wherein forming said second layer of said liner material comprises depositing a material layer comprising tantalum.
11. The method of claim 1 , wherein forming said first layer of said liner material inside of said opening comprises forming a substantially vertical portion of said first layer adjacent to said substantially vertical surface, said substantially vertical portion having a thickness of approximately 5 nm or less.