A silicon carbide bipolar junction transistor

Abstract

A silicon carbide bipolar junction transistor belongs to the technical field of high-power semiconductor devices. Including collector electrodes 7, N stacked sequentially from bottom to top + Substrate 6, N ‑ The collector region 5 and the P-type base region 4, one end of the upper surface of the P-type base region 4 has an N on which the emitter 1 is arranged on the upper surface. + The emitter region 3, the other end has the first secondary epitaxial P+ region 10 with the base 2 set on the upper surface, the first secondary epitaxial P+ region 10 and the N + The upper layer of the P-type base region 4 between the emitter regions 3 has a second secondary epitaxial P+ region 9, a first secondary epitaxial P+ region 10, a second secondary epitaxial P+ region 9 and N + The emitter regions 3 are separated by a dielectric layer 8, and the dielectric layer 8 is along the N + The upper surface of the emitter region 3 extends to the side away from the base 2 and is connected to the emitter 1, and the dielectric layer 8 extends along the upper surface of the first secondary epitaxial P+ region 10 to the side away from the emitter 1 and is connected to the base 2 . The invention reduces the complexity of the process, improves the yield and reliability of the device, and improves the current gain of the SiC BJT device.

Description

technical field [0001] The invention belongs to the technical field of high-power semiconductor devices, and relates to a silicon carbide bipolar junction transistor. Background technique [0002] The wide bandgap semiconductor material SiC is an ideal material for preparing high-voltage power electronic devices. Silicon carbide (SiC) bipolar junction transistor (BJT) is one of the important normally-off devices. Advantages. Compared with Si-based transistors, SiC BJT has the advantages of lower turn-on voltage and no secondary breakdown phenomenon; SiC BJT avoids the gate drive problem of normally-on device SiC JFET, and does not have the disadvantage of large conduction loss of SiC IGBT , there is no problem that the working conditions of the SiC MOSFET are limited due to the poor stability of the gate dielectric and the low mobility of the channel. [0003] The existence of SiC / SiO2 high interface state will lead to the instability of the gate dielectric of SiC MOSFET, ...

AI Technical Summary

Problems solved by technology

[0004] What the present invention aims to solve is that there are a large number of interface states on the surface of the outer base region between the edge of the emitter mesa and the ohmic contact of the base of the current silicon carbide bipolar junction transistor, and these interface states will become carrier recombination centers, resulting in A large number of minority carriers (electrons) in the base region recombine at the interface to generate a recombination current, which reduces the current gain of the device and leads to the degradation of device performance. A silicon carbide bipolar junction transistor is provided

Images