Highly reliable ECR N2O-plasma polyoxide grown on heavily phosphorus-doped polysilicon films

Abstract

Reliability of polyoxide grown by electron cyclotron resonance (ECR) N2O-plasma on heavily phosphorus-doped polysilicon has been investigated for the interpoly dielectrics (IPDs) of nonvolatile memories (NVMs). ECR N2O-plasma polyoxide grown on polysilicon with phosphorus of 1 x 10(21) cm(-3) exhibits a significantly high breakdown field of 10 MV/cm and low electron trapping rate of 0.5 V, which are regardless of phosphorus concentration. The improvements are attributed to the smooth polyoxide/polysilicon interface, low phosphorus concentration, and nitrogen-rich layer with strong silicon-nitrogen bonds at the polyoxide/polysilicon interface.