| 摘要 |
PURPOSE:To improve the reverse breakdown strength of a drain and to improve the breakdown strength of a transistor, by providing an opposite conductivity type second impurity region at a specified depth at a part, between the first and second impurity regions in the surface of the drain. CONSTITUTION:Bases 4 comprising P-type impurities in a specified pattern are provided on the surface of a drain 2, which comprises an N-type low concentration impurity layer on an N-type high concentration semiconductor substrate 1. A P-type impurity region 3 is provided at a specified depth in the surface of the drain 2 between corner parts 4a of the bases 4. An N-type source 5 is provided on the surface of each base 4. A gate 6 is provided on at least a part of each base 4 between the drain 2 and the source 5 through a gate insulating film. An insulating film 7 having connecting windows is provided on the impurity regions 3, the bases 4 and the sources 5. A source electrode 8 is further provided. The impurity region 3, the bases and the sources 5 are connected in this constitution. Therefore, the concentration of an electric field at the corner part 4a of the base 4 is alleviated, and the electric field is uniformly distributed. Thus, the reverse breakdown strength is improved, and the breakdown strength of the transistor can be improved. |
