Abstract: A high power vertical insulated-gate switch is described that includes an active region, containing a cell array, and a surrounding termination region. The termination region is for at least the purpose of controlling a breakdown voltage and does not contain any switching cells. Assuming the anode is the silicon substrate (p-type), it is desirable to have good hole injection efficiency from the substrate in the active region in the device's on-state. Therefore, the substrate should be highly doped (p++) in the active region. It is desirable to have poor hole injection efficiency in the termination region so that there is a minimum concentration of holes in the termination region when the switch is turned off. Various doping techniques are disclosed that cause the substrate to efficiency inject holes into the active region but inefficiently inject holes into the termination region during the on-state.

Abstract: 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. The cells further contain a vertical p-channel MOSFET, for shorting the base of the npn transistor to its emitter, to turn the npn transistor off when the p-channel MOSFET is turned on by a slight negative voltage applied to the gate. The p-channel MOSFET includes a Schottky source formed in the top surface of the npn transistor emitter.

Abstract: An insulated gate turn-off (IGTO) device has a PNPN layered structure so that vertical NPN and PNP transistors are formed. Trench gates are formed extending into the intermediate P-layer. The device is formed of an array of cells. A P-channel MOSFET, having a trenched gate, is formed in some of the cells. The control terminal of the IGTO device is connected to the insulated gates of all cells, including to the gate of the P-channel MOSFET, and to the intermediate P-layer. To turn the device on, a positive voltage is applied to the control terminal to turn on the NPN transistor by forward biasing its base-emitter. To turn off the IGTO device, a negative voltage is applied to the control terminal to turn on the P-channel MOSFET to short the NPN base to its emitter.

Abstract: An insulated gate turn-off thyristor has a layered structure including a p+ layer (e.g., a substrate), an n-epi layer, a p-well, vertical insulated gate regions formed in the p-well, and an n-layer over the p-well and between the gate regions, so that vertical npn and pnp transistors are formed. The p-well has an intermediate highly doped portion. When the gate regions are sufficiently biased, an inversion layer surrounds the gate regions, causing the effective base of the npn transistor to be narrowed to increase its beta. When the product of the betas exceeds one, controlled latch-up of the thyristor is initiated. The p-well's highly doped intermediate region enables improvement in the npn transistor efficiency as well as enabling more independent control over the characteristics of the n-type layer (emitter), the emitter-base junction characteristics, and the overall dopant concentration and thickness of the p-type base.

Abstract: 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 regions formed in the p-well, and n+ regions between the gate regions, 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, referenced to the cathode. The cells further contain a vertical p-channel MOSFET, for shorting the base of the NPN transistor to its emitter, to turn the NPN transistor off when the p-channel MOSFET is turned on by a slight negative voltage applied to the gate. This allows the IGTO device to be more easily turned off while in a latch-up condition, when the device is acting like a thyristor.

Abstract: An insulated gate turn-off thyristor has a layered structure including a p+ layer (e.g., a substrate), an n? layer, a p-well, vertical insulated gate regions formed in the p-well, and n+ regions between the gate regions, so that vertical NPN and PNP transistors are formed. Some of the gate regions are first gate regions that only extend into the p-well, and other ones of the gate regions are second gate regions that extend through the p-well and into the n? layer to create a vertical conducting channel when biased. The second gate regions increase the beta of the PNP transistor. When the first gate regions are biased, the base of the NPN transistor is narrowed to increase its beta. When the product of the betas exceeds one, controlled latch-up of the thyristor is initiated. The distributed second gate regions lower the minimum gate voltage needed to turn on the thyristor.

Abstract: An insulated gate turn-off (IGTO) device has a layered structure including a p+ layer (e.g., a substrate), an n-type layer, a p-type layer (which may be a p-well), n+ regions formed in the surface of the p-type layer, and insulated planar gates over the p-type layer between the n+ regions. The layered structure forms vertical NPN and PNP transistors. The p-type layer forms the base of the NPN transistor. When the gates are sufficiently positively biased, the underlying p-type layer inverts to reduce the width of the base to increase the beta of the NPN transistor. This causes the product of the betas of the NPN and PNP transistors to exceed one, and the device becomes fully conductive. When the gate voltage is removed, the base width increases such that the product of the betas is less than one, and the device shuts off. No latch-up occurs in normal operation.

Abstract: 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.

Abstract: Methods and systems for a gate-controlled thyristor which switches between narrow-base operation in the ON state and wide-base operation in the OFF state, and which can only sustain latch-up in the narrow-base ON state.

Abstract: An insulated gate turn-off thyristor, formed as a die, has a layered structure including a p+ layer (e.g., a substrate), an n? layer, a p-well, vertical insulated gate regions formed in the p-well, and n+ regions between the gate regions, so that vertical NPN and PNP transistors are formed. The thyristor is formed of a matrix of cells. Due to the discontinuity along the edge cells, a relatively large number of holes are injected into the n? epi layer and drift into the edge p-well, normally creating a higher current along the edge and lowering the breakover voltage of the thyristor. To counter this effect, the dopant concentration of the n+ region(s) near the edge is reduced to reduce the NPN transistor beta and current along the edge, thus increasing the breakover voltage. Alternatively, a deep trench may circumscribe the edge cells to provide isolation from the injected holes.

Abstract: 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.

Abstract: An insulated gate turn-off (IGTO) device has a layered structure including a p+ layer (e.g., a substrate), an n-type layer, a p-type layer (which may be a p-well), n+ regions formed in the surface of the p-type layer, and insulated planar gates over the p-type layer between the n+ regions. The layered structure forms vertical NPN and PNP transistors. The p-type layer forms the base of the NPN transistor. When the gates are sufficiently positively biased, the underlying p-type layer inverts to reduce the width of the base to increase the beta of the NPN transistor. This causes the product of the betas of the NPN and PNP transistors to exceed one, and the device becomes fully conductive. When the gate voltage is removed, the base width increases such that the product of the betas is less than one, and the device shuts off. No latch-up occurs in normal operation.

Abstract: Methods and systems for lateral switched-emitter thyristors in a single-layer implementation. Lateral operation is advantageously achieved by using an embedded gate. Embedded gate plugs are used to controllably invert a portion of the P-base region, so that the electron population at the portion of the inversion layer which is closest to the anode will provide a virtual emitter, and will provide sufficient gain so that the combination of bipolar devices will go into latchup.

Abstract: An integrated trench-MOS-controlled-thyristor plus trench gated diode combination, in which the trenches are preferably formed at the same time. A backside polarity reversal process permits a backside p+ region in the thyristor areas, and only a backside n+ region in the diode areas (for an n-type device). This is particularly advantageous in motor control circuits and the like, where the antiparallel diode permits the thyristor to be dropped into existing power MOSFET circuit designs. In power conversion circuits, the antiparallel diode can conveniently serve as a freewheeling diode.

Abstract: Methods and systems for a gate-controlled thyristor which switches between narrow-base operation in the ON state and wide-base operation in the OFF state, and which can only sustain latch-up in the narrow-base ON state.

Abstract: An insulated gate turn-off thyristor has a layered structure including a p+ layer (e.g., a substrate), an n? layer, a p-well, vertical insulated gate regions formed in the p-well, and n+ regions between the gate regions, so that vertical NPN and PNP transistors are formed. Some of the gate regions are first gate regions that only extend into the p-well, and other ones of the gate regions are second gate regions that extend through the p-well and into the n? layer to create a vertical conducting channel when biased. The second gate regions increase the beta of the PNP transistor. When the first gate regions are biased, the base of the NPN transistor is narrowed to increase its beta. When the product of the betas exceeds one, controlled latch-up of the thyristor is initiated. The distributed second gate regions lower the minimum gate voltage needed to turn on the thyristor.

Abstract: An integrated trench-MOS-controlled-thyristor plus trench gated diode combination, in which the trenches are preferably formed at the same time. A backside polarity reversal process permits a backside p+ region in the thyristor areas, and only a backside n+ region in the diode areas (for an n-type device). This is particularly advantageous in motor control circuits and the like, where the antiparallel diode permits the thyristor to be dropped into existing power MOSFET circuit designs. In power conversion circuits, the antiparallel diode can conveniently serve as a freewheeling diode.

Abstract: An insulated gate turn-off thyristor, formed as a die, has a layered structure including a p+ layer (e.g., a substrate), an n? layer, a p-well, vertical insulated gate regions formed in the p-well, and n+ regions between the gate regions, so that vertical NPN and PNP transistors are formed. The thyristor is formed of a matrix of cells. Due to the discontinuity along the edge cells, a relatively large number of holes are injected into the n? epi layer and drift into the edge p-well, normally creating a higher current along the edge and lowering the breakover voltage of the thyristor. To counter this effect, the dopant concentration of the n+ region(s) near the edge is reduced to reduce the NPN transistor beta and current along the edge, thus increasing the breakover voltage. Alternatively, a deep trench may circumscribe the edge cells to provide isolation from the injected holes.

Abstract: An integrated trench-MOS-controlled-thyristor plus trench gated diode combination, in which the trenches are preferably formed at the same time. A backside polarity reversal process permits a backside p+ region in the thyristor areas, and only a backside n+ region in the diode areas (for an n-type device). This is particularly advantageous in motor control circuits and the like, where the antiparallel diode permits the thyristor to be dropped into existing power MOSFET circuit designs. In power conversion circuits, the antiparallel diode can conveniently serve as a freewheeling diode.

Abstract: 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 regions formed in the p-well, and n+ regions between the gate regions, 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, referenced to the cathode. The cells further contain a vertical p-channel MOSFET, for shorting the base of the NPN transistor to its emitter, to turn the NPN transistor off when the p-channel MOSFET is turned on by a slight negative voltage applied to the gate. This allows the IGTO device to be more easily turned off while in a latch-up condition, when the device is acting like a thyristor.