Patent ID: 7141831

Claim:
An SCR device having an anode terminal and a cathode terminal, said device comprising: a semiconductor body having a first surface; a first P type semiconductor region electrically connected to the anode terminal; at least one N type semiconductor region disposed in the semiconductor body, with the first P type semiconductor region and the at least one N type semiconductor region forming at least one PN junction, with the at least one PN junction having a total width Wn near the first surface and which is in a direction substantially normal to current flow between the anode and the cathode and which conducts a substantial portion of current flow between the first P type region and the at least one N type region; at least one further P type semiconductor region disposed in the semiconductor body, with the at least one N type semiconductor region and the at least one further P type region forming at least one PN junction having a total width Wp near the first surface in the direction normal to the current flow between the anode and cathode, with width Wp being at least 1.5 times width Wn; at least one further N type semiconductor region electrically connected to the cathode terminal, with the at least one further P type semiconductor region and the at least one further N type semiconductor region forming at least one PN junction there between and wherein a four layer PNPN structure is formed by the first P type, the at least one N type, the at least one further P type and the at least one further N type semiconductor regions.