LATERAL INSULATED GATE TURN-OFF DEVICES

摘要

A lateral insulated gate turn-off (IGTO) device includes an n-type layer, a p-well formed in the n-type layer, a shallow n+ type region formed in the well, a shallow p+ type region formed in the well, a cathode electrode shorting the n+ type region to the p+ type region, at least one trenched gate extending through the n+ type region and into the well, a p+ type anode region laterally spaced from the well, and an anode electrode electrically contacting the p+ type anode region. The structure forms a lateral structure of NPN and PNP transistors, where the well forms the base of the NPN transistor. When a turn-on voltage is applied to the gate, the p-base has a reduced width, resulting in the beta of the NPN transistor increasing beyond a threshold to turn on the IGTO device by current feedback.

主权项

1. A lateral insulated gate turn-off (IGTO) device formed as a die comprising:
a first semiconductor layer of a first conductivity type; a well of a second conductivity type formed in the first semiconductor layer; a first region of the first conductivity type formed in the well and shallower than the well; a second region of the second conductivity type formed in the well and shallower than the well, the second region having a dopant concentration higher than a dopant concentration of the well; a first electrode shorting the first region to the second region; at least one trenched first gate extending through the first region and into the well, the first gate not extending outside of the well; a third region of the second conductivity type formed in the first semiconductor layer and laterally spaced from the well; and a second electrode electrically contacting the third region; wherein a lateral structure of NPN and PNP transistors is formed, and wherein the well forms a first base of one of the transistors; the well having dimensions and a dopant concentration such that, when a forward biasing voltage is applied between the first electrode and the second electrode and when a turn-on voltage is applied to the first gate, the first gate creates an inversion layer in the well to cause the first base to have a reduced width, resulting in the beta of the one of the transistors to increase beyond a first threshold to turn on the IGTO device to conduct a lateral current between the first electrode and the second electrode, wherein, when a turn-off voltage is applied to the first gate, the first base has an increased width to cause the beta of the one of the transistors to be reduced below a second threshold to turn off the IGTO device.