Semiconductor switching devices

摘要

A process for manufacturing a semiconductor switching device (such as a thyristor device) comprises: etching a face of a semiconductor body to provide islands and channels which define a mesa-contoured surface; diffusing dopant of a first conductivity type through said surface so that the lines of equal concentration of the dopant in said body follow substantially the mesa-contoured surface; and diffusing dopant of a second conductivity type into said islands to form p-n junctions with said dopant of a first conductivity type. The diffusion of said dopant of a first conductivity type is followed by an out-diffusion step so that the dopant concentration of said dopant of a first conductivity type is at a maximum at a depth below said surface.