Groove type SOI LIGBT comprising carrier storage layer

Abstract

The invention belongs to the field of power semiconductor technology and relates to a groove type SOI LIGBT comprising a carrier storage layer. The groove type SOI LIGBT relative to a structure in the prior art comprises the following characteristics: 1, the groove type SOI LIGBT comprises the carrier storage layer in high concentration which blocks a hole in forward conduction, the concentration of the hole near an interface is increased, according to an electroneutrality principle, more electrons is injected to a drift region, the conductivity modulation effect is enhanced, and the forward conduction voltage drop of a device is reduced, simultaneously, a medium groove is introduced, the medium groove physically block a cathode to collect the hole and acts on further reduction of forward conduction voltage drop, and more importantly, the medium groove can assistant to drain the carrier storage layer in forward blocking, so that the device maintains high pressure resistance in the condition of high concentration carrier storage layer; 2. the groove type SOI LIGBT adopts tri-gate structure, and the channel density is improved; 3. tri-gate structure and the medium groove can be manufactured simultaneously without extra processing steps.

Description

technical field [0001] The invention belongs to the technical field of power semiconductors, and relates to a slot-type SOI LIGBT with a carrier storage layer. Background technique [0002] LIGBT is a structure composed of lateral field effect transistors and bipolar transistors. It has the advantages of high input impedance of field effect transistors, low control power, simple driving circuit, high current density of bipolar transistors, and low saturation voltage. . SOI LIGBT is compatible with standard CMOS circuits and is widely used in high-voltage integrated circuits, and its SOI substrate can play a role of complete dielectric isolation. [0003] The current density capability of high-voltage LIGBT has a great influence on the driving capability, so increasing its current density capability becomes the key to improving chip performance and reducing chip cost. The high current capability of LIGBT stems from the conductance modulation effect in its drift region. By i...

AI Technical Summary

Problems solved by technology

However, when the LIGBT is turned off, a large number of unbalanced electron-hole pairs stored in the drift region need to be extracted. These carriers are far away from the withstand voltage PN junction formed by the P-type body region and the N-type drift region, so they cannot be used when the LIGBT is turned off. The built-in electric field in the depleted region quickly sweeps out of the drift region, causing adverse effects such as long turn-off time and large turn-off loss

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