Patent ID: 6900109

Claim:
A method of manufacturing a semiconductor device including an alternating conductivity type layer formed of vertical first regions of a first conductivity type and vertical second regions of a second conductivity type, the vertical first regions and the vertical second regions being alternately arranged with each other, each of the vertical first regions or each of the vertical second regions being formed of epitaxially grown layers laminated with each other, each of the vertical second regions or each of the vertical first regions being formed of buried diffusion unit regions connected vertically with each other, and each of the vertical first regions and each of the vertical second regions including a vertical impurity concentration profile comprising at least one peak and at least two valleys, the method comprising the steps of: (a) forming an epitaxially grown layer doped relatively lightly on a substrate; (b) non-selectively implanting impurity ions of the first conductivity type or the second conductivity type in the entire surface portion of the epitaxially grown layer; (c) selectively implanting impurity ions of the second conductivity type or the first conductivity type into diffusion centers in the surface portion of the epitaxially grown layer; (d) repeating the steps (a) through (c) to form a laminate including a desired number of the diffusion centers aligned vertically; and (e) thermally diffusing the implanted impurity ions from the diffusion centers, to connect the buried diffusion unit regions vertically with each other.