Semiconductor device and method of making same

A method of making a semiconductor device comprising the steps of:

• forming a plurality of regions having an N-type behavior by adding an impurity providing the N-type behavior to a semiconductor thin film;
• forming a plurality of low concentration impurity regions each including the impurity providing the N-type behavior by a concentration lower than a concentration of each of the plurality of regions having the N-type behavior by adding the impurity providing the N-type behavior by a concentration lower than a concentration of the impurity providing the N-type behavior in the preceding step;
• and
• adding selectively an impurity providing a P-type behavior whereby at least portions of the plurality of regions having the N-type behavior are inverted to regions having the P-type behavior and simultaneously inverting at least portions of the plurality of low concentration impurity regions into regions having the P-type behavior more potential than the regions inverted to have the P-type behavior.

A method of making a semiconductor device comprising the step of:

• adding an impurity providing a P-type behavior to a semiconductor thin film comprising:
• regions having an N-type behavior;
• and
• low concentration impurity regions including an impurity providing the N-type behavior by a concentration lower than a concentration of the impurity providing the N-type behavior of the regions having the N-type behavior;
• whereby the regions having the N-type behavior are inverted to a source and a drain region and simultaneously the low concentration impurity regions are inverted to regions having the P-type behavior more potential than the P-type behavior of the source and the drain regions;
• and
• arranging one of the regions having the potential P-type behavior between the source region and a channel forming region.