Patent ID: 7465965

Claim:
A semiconductor device comprising: a bulk semiconductor substrate; an access transistor; a thyristor formed on said bulk semiconductor substrate connecting to said access transistor; an element separating region that separates said access transistor and said thyristor from each other; a wiring layer connecting a diffused layer of said access transistor and a cathode of said thyristor through a connecting hole; and a first voltage source connected to an anode side of the thyristor; wherein the thyristor includes an impurity region on the anode side of said thyristor comprising a first p-type impurity region, a first n-type impurity region, a second p-type impurity region, and a second n-type impurity region, which are formed sequentially in the depthwise direction ;and the lowermost n-type impurity region being directly connected to a second voltage source that applies the same voltage as the first voltage source during data holding; the anode of said thyristor being located at the first p-type impurity region formed on a top surface of the bulk semiconductor substrate at the anode side of the thyristor, and the cathode of said thyristor being formed on said top surface of the bulk semiconductor substrate.