Compatibility of Hf_xTa_yN metal gate electrode with HfO_xN_y gate dielectric for advanced CMOS technology

摘要

Compatibility and thermal stability of the metal-oxide-semiconductor (MOS) device with HfO_xN_y gate dielectric and Hf_xTa_yN metal gate electrode were investigated. MOS device formed by Hf_xTa_yN metal gate and HfO_xN_y gate dielectric shows excellent thermal stability. Compared to the TaN metal gate, Hf_xTa_yN 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_xN_y gate dielectric and Hf_xTa_yN metal gate.