MANUFACTURE OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: To eliminate the need for a mask when introducing an impurity for forming relatively high and relatively low dope regions of an opposite conduction type. CONSTITUTION: A semiconductor substrate 1 has a one-conductive type first region near a first main, surface 2 and an insulation layer 5 on one main surface. An impurity is introduced into the insulation layer 5 on a first region 20 and a second region 21 on one main surface 2 via windows 8 and 10 that are formed by a masking means, and a relatively high dope region 11 of opposite-conductive type and a relatively low dope region 12 of opposite- conductive type are formed near the first region 20 and the second region 21, respectively. Then, one-conductive impurity for forming a region 13 is introduced into a low dope region 12 of opposite-conductive type. A surface 5a of the insulation layer 5 is exposed before introduction, and an impurity is introduced with an amount of injection that is sufficient for forming a region 13 but is not sufficient for excessively doping the high dope region 11. The thickness of the insulation layer is selected so that the one-conductive type impurity is transmitted and the dope of a surface layer 40 at a first region is increased.