Compatibility of PolySilicon with HfO_2-based Gate Dielectrics for CMOS Applications

摘要

Hafnium-based materials such as oxides,silicates and aluminates of hafnium are being widely studied for application as high-K gate dielectric to meet the needs of CMOS scaling.For rapid deployment of high-K gate dielectrics into existing CMOS lines,compatibility of the high-K dielectric with polysilicon gate electrodes is critical.It is therefore necessary to evaluate the stability of the high-K gate dielectric during polySi deposition and CMOS processing.Previous studies [1,2] have reported that exposure to SiH_4 during CVD polySi deposition leads to reduction of HfO_2 and causes high leakage failures.