Sub-Nm Screening Layer Approach for Ultra Shallow Junction Formation

Abstract

ABSTRACTThis paper describes the influence of the sub-nm screening and capping oxide layer of wet process on B diffusion for 50 nm shallow junction formation. The reason is proposed that the knock-on oxygen into Si makes B diffusion faster such as in the case of oxidation enhanced diffusion. To suppress the B enhanced diffusion, the screening oxide formed before implant should be thin to reduce the knock-on oxygen. The wet process before annealing strongly influences the B diffusion, in particular, thicker capping oxide with sub-oxide structure and knock-on oxygen has an important rule for the enhanced diffusion.