Bilayer silicon carbide based barrier

摘要

A bilayer SiC-based barrier is formed over a metallic wiring layer and a first dielectric layer. The bilayer SiC-based barrier consists of a nitrogen-doped SiC bottom layer and an oxygen-doped SiC top layer. The nitrogen-doped SiC bottom layer has a minimum thickness to prevent metal atoms of the metallic wiring layer from diffusing out to a second dielectric layer and, at the same time, avoid oxygen atoms of the oxygen-doped SiC top layer from diffusing into the metallic wiring layer.