Power thyristor having a high triggering speed

Claim 1

In a power thyristor having a high triggering speed, said thyristor comprising: a semi-conductor monocrystalline plate with an anode face and a cathode face, said plate comprising successively, from the anode face to the cathode face, an anode of the P type, an intermediate layer of the N type, a base of the P type and a layer of emitters of the N type having gaps taken up by the base, so that the cathode face comprises, at least, a central region of the base, a triggering emitter surrounding that central region, an intermediate region of the base surrounding that triggering emitter and a main emitter surrounding that intermediate region and having a greater area than said triggering emitter; a trigger formed by a metallic layer deposited on said central region of the base at a distance from said triggering emitter; an auxiliary metal spray deposited on said triggering emitter spaced at a distance from said central region of the base and overlapping onto said intermediate region of the base; a cathode formed by a metallic layer deposited on said main emitter at a distance from said intermediate region of the base; two main terminals, one connected to said anode and the other connected to said cathode; a control terminal connected to said trigger; the improvement comprising: the outside edge of said intermediate region of the base having a corrugated shape, with valleys extending radially towards said central region and peaks extending radially away from that central region, and wherein the height of said peaks in relation to said valleys, measured radially from said central region, is between 20 percent and 5 percent of the width of said main emitter, measured in the same direction.