Novel Shallow Counter Doping Process and High Performance Buried Channel pMOSFET Using Boron Diffusion Through Oxide

With scaling down of ppchannel MOSFET, much attention has been paid for surface channel (SC) pMOSFET with p+ poly-Si gate, since it has superior short channel effects immunity, while conventional buried channel (BC) pMOSFETs have strong threshold voltage dependence of short channel effect and sub-threshold characteristics. However, BC pMOSFETs with n+ poly-Si gate have advantage in channel mobility and drain current because of smaller normal electric field in the channel. Thus, it promises high performance if it is successfully scaled.