SEMICONDUCTOR DEVICE

The invention relates to a semiconductor device. Provided is a nonvolatile memory having a small area and sufficient capacitance. The semiconductor device constituting the non-volatile memory includes a semiconductor portion of a first conductivity type; a first well of a second conductivity type, which has a polarity opposite to that of the first conductivity type, and is formed so as to extend inward from a first region within one surface of the semiconductor section; a second well of a second conductivity type formed so as to be separated from the first region and extending inward from a second region within the one surface of the semiconductor part; an insulating film formed on one surface; and a conductive layer formed so as to extend across a region above the first well and a region above the second well on the insulating film. In the first well, a trench extending from one surface to the inside of the first well is formed, and the insulating film extends on the inner surface of the trench. A conductive