POWER DEVICE AND ITS PRODUCTION METHOD

摘要

PURPOSE: The device is to improve the avalanche energy characteristics of single pulse without affecting to threshold voltage of channel area. A most appropriate method for producing the power device is also provided. CONSTITUTION: In this device and method, P+ base area is formed by using trench and, a first and a second conductive type substrates of high concentration are prepared. A first conductive type epitaxial layer(32) of low concentration is formed on the substrates whereas a second conductive type shallow base area(36) of low concentration is formed near the surface of the epitaxial layer. A first conductive type source area(38) of high concentration is formed near the surface of the shallow base area. A trench(40) is formed to pass through the source area and the base area. An embedding conductive layer(42) on which impurities are doped is formed to fill the trench. A second conductive type deep base area of high concentration is formed to surround the trench and in junction with lower end portion of the source area. A gate electrode(50) is formed via thermal oxidization film on the epitaxial layer between the source areas. A metal interconnect(56) is connected to the embedding conductive layer and the source areas. Thus, it is possible to minimize the change of threshold voltage due to the excessive expansion of the deep base area, and keep the quality stable by protect destruction of elements due to adverse currents.