Reliability Assessment on Highly Manufacturable MOSFETs with Metal Gate and Hf based Gate Dielectrics

After over 10 years of intensive study on high-k dielectric and metal gate electrode to replace silicon based materials (Si02 or SiON gate dielectric and polysilicon gate) in the complementary-metal-oxide-semiconductor (CMOS) application, it was claimed that hafnium based dielectric and metal gate are finally ready to be implemented in 45nm technology and beyond. It was reported that the minority carrier mobility in the metal-oxide-semiconductor field effect transistor (MOSFET) with hafnium oxide (Hf02) was improved significantly and performance reaches the comparable level of that of MOSFETs with silicon oxynitride even with further scaled equivalent oxide thickness (EOT). Since the device performance has been optimized, the focus of the high-k dielectric study shifts toward the device reliability issues.