Preparation method of FS-IGBT

Abstract

The invention provides a method for preparing an FS-IGBT (Field Stop-Insulated Gate Bipolar Translator) on a silicon wafer, which is used for solving the problems caused by a thin silicon wafer during a preparation process of a medium / low-voltage FS-IGBT that the preparation technology is complicated, the difficulty is large, the thin silicon wafer warps and deforms and is segmented, the size of the thin silicon wafer (a wafer) is limited, the yield is low, the cost is high, and industrialization is difficult to realize and overcoming the huge technical challenge caused by the thin silicon wafer in follow-up scribing of the wafer and encapsulating of a chip. The preparation method comprises the steps of selecting light-doped FZ silicon as a first silicon wafer and heavy-doped CZ silicon or FZ silicon as a second silicon wafer; firstly, making an N-type FS layer and a P-type transparent collecting zone on the back surface of the first silicon wafer; then, bonding the first silicon wafer and the second silicon wafer; making a front-surface structure by thinning the thickness of the first silicon wafer; finally, thinning the second silicon wafer; forming a collector electrode through etching, metal depositing and chemical-mechanical polishing; obtaining the FS-IGBT.

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 a field stop type insulated gate bipolar transistor (FS-IGBT). Background technique [0002] Insulated gate bipolar transistor (IGBT) is a new type of power electronic device combined with MOS field effect and bipolar transistor. The advantages of large current and low loss have become one of the core electronic components in modern power electronic circuits, and are widely used in various fields of the national economy such as communications, energy, transportation, industry, medicine, household appliances, and aerospace. The invention and application of IGBT have played an extremely important role in improving the performance of power electronic systems. Since the 1990s, through the continuous development of device structure and manufacturing technology, commercial mass-produ...

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Problems solved by technology

[0008] The purpose of the present invention is to propose a method for preparing FS-IGBT on a thick silicon wafer to solve the complex and difficult preparation process caused by thin silicon wafers during the preparation process of medium and low voltage FS-IGBTs, warping of silicon wafers, Deformation, fragmentation, limited size of silicon wafer (wafer), low yield, high cost, difficulty in realizing industrialization, and huge problems caused by thin silicon wafers in subsequent wafer dicing and chip packaging technical challenge

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