Method for manufacturing insulated gate bipolar transistor

Abstract

The invention discloses a method for manufacturing an insulated gate bipolar transistor, comprising the following steps: providing a semiconductor substrate of a first conductivity type, selectively forming a deep well region of a second conductivity type at a first main surface side of an active region of the semiconductor substrate, and selectively forming a protection terminal of the second conductivity type in a terminal protection region around the active region; implanting ions of the first conductivity type at the first main surface side of the active region of the semiconductor substrate of the first conductivity type; selectively photoetching and etching a gate oxide layer and a polycrystalline silicon layer to form a polycrystalline silicon gate and a window; and continuing to implant ions of the second conductivity type in the position of the deep well region at the first main surface side of the active region of the semiconductor substrate based on the window and activating the ions to form a base region of the second conductivity type. On the premise of not increasing the thermal process or even reducing the thermal process, the well junction depth is expanded largely, the anti-latch-up capability is improved, and the application reliability of products is improved.

Description

technical field [0001] The invention belongs to the technical field of power semiconductor devices, and relates to an insulated gate bipolar transistor (IGBT), especially a preparation method of an insulated gate bipolar transistor with strong anti-latch capability. Background technique [0002] IGBT (Insulated Gate Bipolar Transistor, insulated gate bipolar transistor) has a parasitic PNPN thyristor between the collector and emitter, such as Figure 13 shown. Under special conditions (α pnp +α npn ≥1), this parasitic device turns on. This phenomenon increases the amount of current flowing between the collector and emitter, reduces the ability to control the equivalent MOSFET, and often causes device breakdown problems. Thyristor conduction phenomenon is called IGBT latch-up. [0003] There are two models of IGBT latch: (1) Static latch generated when IGBT is turned on; (2) Dynamic latch generated when IGBT is turned off. Static latch-up occurs at low-voltage and high-c...

AI Technical Summary

Problems solved by technology

At present, the production process of IGBT is relatively complicated. Due to the limitation of the existing process, the depth of the P-body well cannot be made too deep; the application reliability of the product is poor, especially the anti-latch-up ability is poor.

[0006] The quality of gate oxide has an impact on product performance. Abnormal gate oxide quality will lead to device failure. Generally, gate oxide is low-temperature oxidation, which has many fixed charges and interface states, and defects are prone to appear on the Si surface; thus affecting the quality of the oxide layer; causing Test failure or gate oxide failure during application

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