Thin silicon-on-insulator (SOI) lateral insulator gate bipolar transistor (LIGBT) with folded groove gate

Abstract

The invention belongs to the technical field of a power semiconductor, and particularly relates to a thin silicon-on-insulator (SOI) lateral insulator gate bipolar transistor (LIGBT) with a folded groove gate. The thin SOI LIGBT is mainly characterized in that a non-equal deep dielectric groove and the folded groove gate are employed; during positive voltage resistance, a transverse electric fieldis modulated by the non-equal deep dielectric groove, and a uniformly-doped drift region bears high voltage; during positive conduction, air is prevented from flowing to an emitter by the dielectricgroove, the hole concentration of a drift region near to the emitter is improved, electron injection improvement effect is achieved, and the conduction voltage drop of the device is reduced; the concentration of the drift region near to one side of a collector is farther lower than the concentration of the drift region at one side of the collector of a traditional thin SOI layer linear doping device, and the injection efficiency of the collector is improved; the electrical conduction modulation effect of the device is improved, the positive conduction voltage drop is reduced, the channel density of the folded groove gate is improved, and the saturation current capability of the device is greatly improved. Compared with a traditional thin SOI LIGBT structure, the thin SOI LIGBT has the beneficial effects of lower positive conduction voltage drop and higher saturation current capability, and Von-Eoff is more excellent in difference.

Description

technical field [0001] The invention belongs to the technical field of power semiconductors, and relates to a thin SOI LIGBT (Lateral Insulator Gate Bipolar Transistor, lateral insulated gate bipolar transistor) with folded trench gates. Background technique [0002] LIGBT has the advantages of high MOSFET input impedance, simple driving, high current density and low conduction voltage of BJT devices, and is easy to integrate. Compared with LDMOS, it has higher current density and smaller conduction voltage drop. [0003] Compared with conventional bulk silicon technology, SOI technology avoids the problems of large leakage current and large turn-off loss of bulk silicon technology, and has high speed, low power consumption, high integration, small parasitic effect, good isolation characteristics, and latch-up effect. It is widely used in consumer electronics such as automotive electronics and switching power supplies due to its small size and strong radiation resistance. ...

AI Technical Summary

Problems solved by technology

The traditional thin SOI LIGBT utilizes the lateral variation doping technique (Lateral Variation Doping Technique) of the top layer silicon to achieve lateral high voltage resistance, such as figure 1 As shown, the thermal process of this process is long and the thermal budget is extremely large; moreover, due to the thin top layer silicon and the existence of carrier recombination at the silicon-oxygen interface, the SOI LIGBT with thin top layer silicon has too large a forward conduction voltage drop and a saturation current The problem is not high enough; in addition, the lateral variable doping technology increases the doping concentration of the drift region of the SOI LIGBT near the collector, which reduces the efficiency of hole injection and further deteriorates the forward conduction voltage drop and current capability of the device.

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