Lateral power device with mixed conduction mode and method of making same

Abstract

The invention provides a lateral power device with a mixed conduction mode and a preparation method thereof, comprising a P-type substrate, a buried oxide layer, an N-type drift region, a P-type base region, an N-type buffer region, an N-type source region, a P-type Contact region, P-type collector region, emitter, collector, gate dielectric layer, gate electrode, N-type drift region surface has N-type strips and P-type strips, N-type strips and P-type strips are perpendicular to the device drift region surface The channel length direction is arranged alternately, and there is a P-type RESURF layer in the drift region under the N-type strip and P-type strip; there is a dielectric groove structure between the N-type strip, P-type strip, and P-type RESURF layer and the N-type buffer zone; The concentration of N-type strips and P-type strips is greater than the concentration of N-type drift regions; the depth of the dielectric groove structure is not less than the depth of N-type strips, P-type strips and P-type collector regions; the invention realizes surface SJ-LDMOS and LIGBT The mixed conduction can obtain lower turn-on voltage drop, higher withstand voltage, faster switching speed, lower turn-off loss, and eliminate the snapback effect, greatly improving device performance.

Description

Technical field [0001] The invention belongs to the technical field of power semiconductor devices, and particularly relates to a lateral power semiconductor device with a mixed conduction mode and a preparation method thereof. Background technique [0002] Lateral Insulated Gate Bipolar Transistor (LIGBT) is a lateral power device that combines the advantages of both lateral power MOSFET and bipolar transistor. It also has the characteristics of high input impedance and reduced conduction voltage. , Is widely used in various power integrated circuits. Compared with traditional devices based on bulk silicon technology, devices manufactured using SOI technology have many advantages such as fast speed, low power consumption, high integration density, strong latch-up resistance, low cost, and good radiation resistance. Therefore, the LIGBT device based on SOI material also has the advantages of good insulation performance, low substrate leakage current, small parasitic capacitance ...

AI Technical Summary

Problems solved by technology

When the LIGBT device is turned on, due to the conductance modulation effect in the drift region, a low turn-on voltage drop can be obtained, but when it is turned off, due to the existence of a large number of unbalanced carriers stored in the drift region, the turn-off time is long, Large turn-off loss

At the same time, due to the existence of the PN junction in the collector area of ​​the device, when the device is conducting forward, in the low collector voltage region, and at the same current density, the conduction voltage drop of LIGBT is larger than that of LDMOS devices, which is not conducive to the reduction of device loss characteristics. Small

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