Surface Protrusions of Chemical Vapor Deposited TiN Films Caused by Cu Contamination of Silicon Substrates

Abstract

We found that surface protrusions of chemical vapor deposited TiN films are caused by reactions between copper contaminants and the silicon substrate. Depending on the size of the copper contaminant, two kinds of defects were formed: copper silicide (CuSi) and silicon dioxide. The silicon dioxide is formed because of the catalytic role of copper silicide. The defects grow both into and out of the silicon substrate. In the formation of copper silicide and silicon dioxide, copper, silicon, and oxygen are the major participating species.

Formation of Novel Silicon Nitride with Face-Centered Cubic Crystal Structure in a TaN/Ta/Si(100) Thin Film System

“…The width of the base of the largest pyramidal precipitate was about 30 nm for the specimen subjected to heat treatment at 500 C. The geometry of these pyramidal precipitates is similar to that of the Cu 3 Si islands generated on a Si(100) wafer with the Cu metallization after barrier failure. 26,27) It is also similar to those of various silicides formed in the solid-state reactions of Si wafers with Pd-Ta, 28) Nb-Ni, 28) Ni-W, 29) or Au. 30) Figure 3(a) shows a TEM bright-field image of the specimen after it was heated at 600 C for 1 h. The width of the base of the largest pyramidal precipitate was about 50 nm.…”