Method of manufacturing semiconductor device, method of manufacturing active matrix substrate, and electrooptic device

Abstract

To provide a method of manufacturing a semiconductor device, a method of manufacturing an active matrix substrate, and an electrooptic device in which in forming different type TFTs on the same substrate, a variation in the LDD length or offset length of TFT can be suppressed by a small number of steps. In the method of manufacturing an active matrix substrate, a patterning mask,used for forming gate electrodes,and,is left, and used in introducing a medium concentration of phosphorus ion to introduce impurities in self alignment with the patterning mask,. Next, with the patterning mask,removed, low-concentration of phosphorus ion is introduced by using the gate electrodes,and,as a mask to form low-concentration source-drain regions,and,in self alignment with the gate electrodes,and,. The LDD length of each of the regions is equal to the amount of side etching caused in patterning the gate electrodes,and