Low damage doping technique for self-aligned source and drain regions

摘要

A process for fabricating a source and drain region which includes a more lightly doped source and drain tip region immediately adjacent to the gate and a more heavily doped main portion of the source and drain region spaced apart from the gate. A first layer of glass (2% BSG) is used to provide the source of doping for the tip region and a second layer of glass (6% BSG) is used to provide the dopant for the more heavily doped major portion of source and drain regions. Spacers are formed between the glass layers to define the tip region from the main portion of the source and drain regions.