Preparation method of field cut-off type insulated gate bipolar transistor

Abstract

A method for preparing a field stop insulated gate bipolar transistor (IGBT) comprises the following steps: providing a substrate (11), and growing a first oxidizing layer (12) on the front and the back of the substrate (11); internally injecting N-type ions from the back of the substrate (11); performing trap pushing on the substrate (11), to make an area injected with N-type ions form a field stop layer (14); removing the first oxidizing layer (12) on the front of the substrate (11); preparing a front structure of the IGBT in the substrate (11) and on the front of the substrate (11) by using an IGBT front process; forming a front protection layer on the front structure; injecting P-type ions into the field stop layer, to form a back P+ layer (23); removing the front protection layer, and performing knotting pushing on the back P+ layer (23); and forming a front metal layer (27) on one of the front structure and the back P+ layer (23), and forming a back metal layer (28) on the other of the front structure and the back P+ layer (23). By growing the first oxidizing layer (12) on the front and forming the front protection layer after the front structure is formed, the front of a wafer can be protected, and the wafer is not easy to be scratched in a manufacturing process.

Description

technical field [0001] The invention relates to a manufacturing method of a semiconductor device, in particular to a manufacturing method of a field-stop insulated gate bipolar transistor. Background technique [0002] Due to the conductance modulation effect, an insulated gate bipolar transistor (Insulated Gate Bipolar Transistor, IGBT for short) has a lower on-resistance than a DMOS. So far, IGBT mainly has three structures: punch-through PT-IGBT, non-punch-through NPT-IGBT and field-stop FS-IGBT. The main differences between the three are different substrate PN junction structures and different drift region thicknesses. . Compared with PT-IGBT and NPT-IGBT, the thickness of FS-IGBT is the thinnest, but the expensive sheet equipment, complicated process and high fragmentation rate seriously limit the performance of FS-IGBT (especially low-voltage IGBT). constantly improving. [0003] On the other hand, for traditional FS-IGBTs, after the FS layer is completed on the bac...

AI Technical Summary

Problems solved by technology

[0004] Based on this, in order to solve the problem that the front side of the wafer (wafer) is easily scratched during the manufacturing process of the traditional insulated gate bipolar transistor, it is necessary to provide a method for preparing a field stop type insulated gate bipolar transistor

Images