A method of manufacturing an insulated gate bipolar transistor

Abstract

The invention discloses a method for manufacturing an insulated gate bipolar transistor, comprising: providing a semiconductor substrate of a first conductivity type, the semiconductor substrate has a first main surface and a second main surface; The substrate is subjected to active area photolithography and ion implantation of the first conductivity type; a base area of ​​the second conductivity type is formed on the first main surface of the active area of ​​the semiconductor substrate of the first conductivity type and a first main area of ​​the active area is formed. A second conductivity type protection terminal is formed outside the surface; the remaining first main surface structure of the insulated gate bipolar transistor is formed on the first main surface of the semiconductor substrate based on the formed base region; on the second main surface of the semiconductor substrate The surface side forms the second main surface structure of the IGBT. The invention provides an IGBT manufacturing method which reduces the number of photolithographic plates used, has simple technological process, reduces manufacturing cost and has high application reliability.

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 preparation method of an insulated gate bipolar transistor with a simplified process. Background technique [0002] IGBT is a composite fully-controlled voltage-driven power semiconductor device composed of GTR (Giant Transistor, power transistor or giant transistor) and MOSFET (Metal-Oxide-Semiconductor-Field-Effect-Transistor, metal-oxide-semiconductor field-effect transistor). It has the advantages of high input impedance of MOSFET and low conduction voltage drop of GTR. It has the characteristics of high operating frequency, simple control circuit, high current density and low on-state voltage. It is widely used in the field of power control. [0003] IGBTs can be classified into planar IGBTs and trench IGBTs according to the structure type of the gate, and the structural features and correspond...

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Problems solved by technology

[0005] The first is to complete the front process on the single crystal silicon substrate, then thin the back of the substrate, and perform multiple ion implantations on the back to form the collector; this method does not depend on the epitaxial process, but relies on high-energy ion implantation As well as the annealing activation process, the equipment cost of high-energy ion implantation is high, and the process implementation cost is also relatively high; moreover, the activation rate of the dopant source in the collector region formed by ion implantation and annealing is not high, which leads to poor saturation characteristics of the IGBT. good

[0006] The second is to grow a thicker epitaxial layer on the single crystal silicon substrate by reverse epitaxial growth, and complete the front process on the epitaxial layer, and then thin the silicon substrate on the back side and form a collector; this method Using the epitaxial process and the epitaxial layer to mainly prepare the IGBT (the epitaxial layer above the buffer layer is formed by the epitaxial layer), the epitaxial layer is relatively thick and the performance requirements of the epitaxial layer are very high (such as the number of defects), often because the quality of the epitaxial layer is not good enough. This leads to poor IGBT performance (for example, poor overvoltage withstand capability and overcurrent withstand capability) or low yield

[0007] With the world's demand for energy saving and emission reduction, IGBTs are used more and more widely. IGBTs are used in various circuits. It is not difficult to find that the existing process flow is a separate photolithography plate for the terminal structure. The process is complicated and the manufacturing cost is high. Therefore, , it is necessary to provide an improved technical solution to overcome the above problems

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