A novel W/TiNx metal gate CMOS technology using nitrogen-concentration-controlled TiNx film

A W/TiN metal gate CMOS technology is newly proposed using a nitrogen-concentration-controlled TiNx film. This is based on a new finding that the threshold voltage of a TiNx gate MOSFET depends on the nitrogen concentration in the TiNx film. The threshold voltage for the W/TiNx gate nMOSFETs is controlled by a low-energy nitrogen ion implantation into the TiN film. This technique using one additional mask is highly compatible with the conventional CMOS process.