A thyristor is disclosed comprising: a first region of a first conductivity type; a second region of a second conductivity type and adjoining the first region; a third region of the first conductivity type and adjoining the second region; a fourth region of the second conductivity type and comprising a first segment and a second segment separate from the first segment, the first segment and second segment each adjoining the third region; a first contact adjoining the first region; a second contact adjoining the first segment; and a trigger contact adjoining the second segment and separate from the second contact.

An insulated gate turn-off (IGTO) device, formed as a die, has a layered structure including a p+ layer (e.g., a substrate), an n epi layer, a p-well, vertical insulated gate electrodes formed in the p-well, and n+ regions between the gate electrodes, so that vertical npn and pnp transistors are formed. The device is formed of a matrix of cells. To turn the device on, a positive voltage is applied to the gate electrodes, referenced to the cathode. To speed up the removal of residual electrons in the p-well after the gate electrode voltage is removed, a p+ region is added adjacent the n+ regions, and an n-layer is added below the p+ region. The cathode electrode directly contacts the p+ region and the n+ regions. During turn-off, the p+ region provides holes which recombine with the residual electrons to rapidly terminate the current flow.