Segmented injection self-clamping IGBT device and manufacturing method thereof

Abstract

The invention provides a segmented injection self-clamping IGBT and a manufacturing method thereof. A trench structure equipotential with an emitter is introduced to the right side of a cell, the P-type doped buried layers are introduced below an N-type charge storage layer, and the high-concentration P-type buried layers are distributed at intervals by changing an opening of a mask plate, so that the adverse effect of the high-concentration P-type buried layers on the threshold voltage when a device is conducted is improved, and the on-resistance is reduced. When the device is saturated, a self-biased PMOS structure is opened, and the electric potential of a CS layer is clamped at a lower value, so that the saturation current of the IGBT is reduced. The high-concentration P-type buried layers distributed at intervals can ensure that the PMOS structure is normally started under high collector voltage so as to clamp the potential of the CS layer, the saturation current is reduced, and the short-circuit capability of the device is improved. On the basis of a traditional trench IGBT process method, the P+ buried layers distributed in a segmented mode in a z direction can be achieved only by adding one mask, the process complexity is not increased, and implementation is easy.

Description

technical field [0001] The invention belongs to the technical field of power semiconductor devices, and relates to an insulated gate bipolar transistor (IGBT), in particular to a segmented injection self-clamping IGBT and a manufacturing method thereof. Background technique [0002] As a new type of power device, insulated gate bipolar transistor (IGBT) combines the gate electrode voltage control characteristics of metal oxide semiconductor field effect transistor (MOSFET) and the low on-resistance characteristics of bipolar junction transistor (BJT), with voltage control , large input impedance, small driving power, small on-resistance, high current density, low switching loss and high operating frequency, it is an ideal semiconductor power switching device, which is obtained in various power conversion, motor drive and power electronic devices. widely used. [0003] Since the advent of the IGBT, people have been working on improving the trade-off relationship between the ...

AI Technical Summary

Problems solved by technology

[0004] In order to improve the problems of large saturation current, poor short-circuit performance, degradation of breakdown characteristics, and increased Miller capacitance caused by deep trenches in the traditional CSTBT structure, the present invention proposes a split Segment-injected self-clamping IGBT structures such as figure 2 As shown, a trench structure with the same potential as the emitter and the same depth as the trench gate is introduced on the right side of the cell, and a high-concentration P-type doped buried layer is introduced under the N-type charge storage layer. By changing the opening of the mask, The high-concentration P-type buried layer is no longer distributed continuously, but is distributed in intervals, which improves the adverse effect of the high-concentration P-type buried layer on the threshold voltage when the device is turned on, and the electron current can pass through undoped P-type impurities. part of the flow into the N-type drift region, greatly reducing the on-resistance

Images