SEMICONDUCTOR DEVICE AND ITS MANUFACTURE

PROBLEM TO BE SOLVED: To provide a semiconductor device for reducing the leak currents of a transistor. SOLUTION: A gate electrode 5 is formed on a semiconductor substrate 1. A pair of p type source/drain layers 9 are formed on both sides of a gate length direction Y of the gate electrode 5 on the surface of the semiconductor substrate 1. An n type gate width deciding layer 15 for deciding the gate width of the gate electrode 5 is formed so that the source/drain layers 9 can be interposed from gate width direction X of the gate electrode 5 on the surface of the semiconductor substrate 1. The source/drain layers 9 and the gate width deciding layer 15 are separated by PN junction.