Laser processing method, method for forming a flash memory, insulated gate semiconductor device and method for forming the same

Abstract

A laser doping process comprising: irradiating a laser beam operated in a pulsed mode to a single crystal semiconductor substrate of a first conductive type in an atmosphere of an impurity gas which imparts the semiconductor substrate a conductive type opposite to said first conductive type and incorporating the impurity contained in said impurity gas into the surface of said semiconductor substrate, thereby modifying the type and/or the intensity of the conductive type thereof. Provides devices having a channel length of 0.5 μm or less and impurity regions 0.1 μm or less in depth.

What is claimed is:  
     
         1 . A memory device comprising: 
 a gate member over a semiconductor;    a source region in the semiconductor;    a drain region in the semiconductor, said drain region having a depth shallower than said source region and not deeper than 0.1 μm;    a channel region being interposed between said source and drain regions and being adjacent to said gate member, and    wherein said source and drain regions extend from a surface of said semiconductor to said depth not longer than a thickness of said semiconductor,    wherein said source region overlaps with said gate member,    wherein said channel region has a length not longer than 0.3 μm.