| 摘要 |
A semiconductor device, that is, transistor, of a high withstand voltage having a LOCOS offset drain, which can cause complete depletion of a drift region and achieve both of an improvement in the junction breakdown voltage and a decrease in the on-resistance, and a method of producing the same. A semiconductor device comprising at least a p-type substrate (1), an n-type epitaxial layer (4) formed on it, a p-well (7) formed in the surface layer of the n-type epitaxial layer (4), an n-type source region (24) formed in the surface layer of the p-well, an n-type drain region (25) formed next to the drain region via an element isolation layer (11) (LOCOS), and a gate electrode (15) formed on the n-type source region (24) and the element isolation layer (11), in which device a p-type buried layer (3) containing an impurity in a higher concentration than that of the p-type substrate (1) is formed, except just below the n-type drain region, in a surrounding pattern around the n-type drain region, and a method of producing the same. <IMAGE> |
