| 摘要 |
PURPOSE:To readily realize the measurement of an accurate punch through voltage of a semiconductor device by forming a one conducting type gate region between the source region and the drain region of a semiconductor layer and forming a reverse conducting high density region on the surface of the semiconductor layer. CONSTITUTION:A p-type epitaxial layer 20 is grown in vapor phase on an n-type semiconductor substrate 10. A substrate pickup region 30 for isolating the layer 20 into a plurality of regions is formed, for example, by selectively diffusing n<+>- type impurity such as phosphrous. Then, a J-FET gate region 40 is formed thereon by a selective oxide and diffusion process. Contact regions 50, 60 for reducing the contact resistance of the source and the drain regions with the electrode metals of the electrode pickup portions are formed by p<+>-type impurity. Thereafter, a region 90 having the same conducting type as the layer 20 and higher impurity density than the layer 20 is formed thereon. |
