Semiconductor device with a p-n junction

摘要

In a semiconductor device having two first conductivity type doped semiconductor layers and a second conductivity type well within the upper more lightly doped layer, the dopant concentration of the more lightly doped layer decreases uniformly from its top surface to a minimum at the interface between the layers. A semiconductor device has (i) first conductivity type doped first and second semiconductor layers (1, 2), the second layer (2) being more lightly doped; (ii) a second conductivity type well (3) extending to a certain depth (d) into the second layer (2); and (c) electrodes (9, 8) respectively on the back face (S1) of the first layer (1) and on the well surface (3S). The dopant concentration of the second layer (2), with the exception of the well (3) is distributed in the depth direction (X1) such that it decreases uniformly from the top surface (S4) of the second layer (2) and reaches a minimum at the interface (BS) between the layers (1, 2). An Independent claim is also included for producing the above semiconductor device, in which the dopant concentration of the epitaxially grown second layer is altered by selective dopant implantation and diffusion only in the second layer to achieve an altered dopant concentration (n) which is less than that (n+) of the first layer but is greater than the original dopant concentration of the second layer.