Method of Forming a Non-volatile Memory Cell Using Off-set Spacers

摘要

A stack of two polysilicon layers is formed over a semiconductor body region. A DDD implant is performed to form a DDD source region in the semiconductor body region along a source side of the polysilicon stack but not along a drain side of the polysilicon stack. Off-set spacers are formed along opposing side-walls of the polysilicon stack. A source/drain implant is performed to form a drain region in the semiconductor body region along the drain side of the polysilicon stack and to form a highly doped region within the DDD source region such that the extent of an overlap between the polysilicon stack and each of the drain region and the highly doped region is inversely dependent on a thickness of the off-set spacers, and a lateral spacing directly under the polysilicon stack between adjacent edges of the DDD source region and the highly doped region is directly dependent on the thickness of the off-set spacers.