METHOD OF REMOVING RIE SIDEWALL VEILS FOR GOLD INTERCONNECT
Original Publication Date: 1997-Jun-01
Included in the Prior Art Database: 2002-May-23
A gold interconnect layer serves as the mask during reactive ion etching (RIE) of a TiWN, refractory gate or diffusion barrier. Since gold has a very high sputter yield, gold is sputtered and redeposited during the RIE step, resulting in gold/polymer veils that form on the sidewalls of the gold metallization (see Figure 1). After subsequent standard wet cleans, residues am observed when the gold veils conglomerate and are m-deposited on the wafer surface. These gold residues are not removable with available cleaning processes.