Insulated gate semiconductor device and method of manufacturing the same

摘要

Dot-pattern-like impurity regions 104 are artificially and locally formed on a channel forming region 103. The impurity regions 104 restrain the expansion of a drain side depletion layer toward the channel forming region 103 to prevent the short channel effect. The impurity regions 104 allow a channel width W to be substantially fined, and the resultant narrow channel effect releases the lowering of a threshold value voltage which is caused by the short channel effect.