| 摘要 |
PURPOSE:To obtain a structure capable of contributing to the reduction of the ON resistance by a method wherein a channel region, of an opposite conductivity type, formed by self-aligned diffusion and a high-concentration region, of the same conductivity type, coming into contact with a semiconductor substrate are formed inside an epitaxial layer, of one conductivity type, on the substrate, of the same conductivity type. CONSTITUTION:A channel region 4, of an opposite conductivity type, formed by self- aligned diffusion and a high-concentration region 10, of the same conductivity type, coming into contact with a semiconductor substrate 1 are formed inside an epitaxial layer 2, of one conductivity type, on the semiconductor substrate 1 of the same conductivity type. For example, after a first n-type epitaxial layer has been formed on an n-type low-resistance silicon substrate 1, its prescribed region is transformed into an n-type high-concentration region 10. Then, a second n-type epitaxial layer is formed; the first and the second epitaxial layers are united; a p-type impurity region 3 is formed on the surface of this epitaxial layer 2. In addition, a gate insulating film and a gate electrode 7 are formed; ions of boron are injected by making use of the gate electrode 7 as a mask; a thermal diffusion process is executed; the second p-type impurity region 4 which is used as a channel region is formed. |
