Insulated-gate photoconductive semiconductor switch

A photoconductive semiconductor switch comprising:

• a semi-insulating substrate, an anode formed on the upper surface of said semi-insulating substrate, a first n-type doped layer formed on the lower surface of said semi-insulating substrate, a p-type doped layer formed on said first n-type doped layer, a second n-type doped layer formed on said p-type doped layer, a cathode formed on said second n-type doped layer, several recesses extending from the surface of said second n-type doped layer towards said first n-type doped layer and vertically extending into a part of said first n-type doped layer, an insulating layer formed on said second n-type doped layer and on the walls and the bottoms of said recesses, a gate electrode consisting of two parts, one part of which formed on said insulating layer on the walls and the bottoms of recesses, and the other part of which formed on a part of the insulating layer on the second n-type doped layer for electrically connecting the part of the gate electrode on the recesses, wherein the cathode and the gate electrode are electrically isolated, wherein the concentration and the thickness parameters of said first n-type doped layer, said p-type doped layer and said second n-type doped layer are designed to ensure that the space-charge region of the reverse-biased p-n junction between said first n-type doped layer and said p-type doped layer will first expand to said semi-insulating substrate rather than to said second n-type doped layer, with the dc bias voltage increasing.