Patent ID: 7078765

Claim:
A semiconductor device, comprising a laterally diffused field effect transistor including, over a semiconductor substrate, an element-forming area and a scribing area surrounding the element-forming area, the transistor including: (a) a semiconductor layer of a first conductive type formed in the element-forming area over the semiconductor substrate, (b) a gate insulating film formed over the semiconductor layer, (c) a gate electrode formed over the gate insulating film, (d) a source comprised of a first semiconductor region of a second conductive type which is different from the first conductive type, (e) a drain comprised of a second semiconductor region of the second conductive type having a first impurity concentration, and a third semiconductor region of the second conductive type having a higher second impurity concentration than the first impurity concentration and being formed at a position farther from the gate electrode than the second semiconductor region, (f) a fourth semiconductor region of the first conductive type where a channel region is formed, (g) an electrode electrically connected to the source and formed over the rear surface of the semiconductor substrate, (h) a source electrode pad, for evaluation, formed in the element-forming area over the front surface of the semiconductor substrate and being electrically connected to the semiconductor substrate, (i) a drain electrode pad formed over the front surface of the semiconductor substrate and being electrically connected to the third semiconductor region, and (k) a gate electrode pad electrically connected to the gate electrode.