Compatibility of Hf xTa yN metal gate electrode with HfO xN y gate dielectric for advanced CMOS technology

Abstract

Compatibility and thermal stability of the metal-oxide-semiconductor (MOS) device with HfO x N y gate dielectric and Hf x Ta y N metal gate electrode were investigated. MOS device formed by Hf x Ta y N metal gate and HfO x N y gate dielectric shows excellent thermal stability. Compared to the TaN metal gate, Hf x Ta y N metal gate shows an enhancement in thermal stability and electrical characteristics, such as equivalent oxide thickness (EOT), hysteresis, interface trap density, stress-induced leakage current and stress-induced flatband voltage shift. With an increase in post metallization annealing (PMA) temperature, the electrical characteristics remain almost unchanged, which, in turn, demonstrate the excellent thermal stability and electrical reliabilities of the MOS device with HfO x N y gate dielectric and Hf x Ta y N metal gate.