Manufacturing process of SBR (sequencing batch reactor) device capable of realizing charge coupling through three-time masking

Abstract

The invention discloses a manufacturing process of an SBR (sequencing batch reactor) device for realizing charge coupling through three-time masking. The manufacturing process comprises the following steps: forming a thin oxide layer; forming a body region; forming a thick oxide layer as a first mask; performing photoetching to form a groove; forming a field oxide layer; forming a first polycrystalline silicon; setting a second mask, and etching the first polycrystalline silicon to enable the top of the first polycrystalline silicon to be lower than the surface of the epitaxial layer; injecting source region ions by taking the thick oxide layer between the active region trenches as a mask; depositing to form a first oxide layer; and the first oxide layer is etched downwards in an isotropic manner, so that the epitaxial layer on the surface of the active region is exposed, an active region contact hole is formed in the active region trench, and the active region contact hole extends into the second polycrystalline silicon. According to the manufacturing process, the whole manufacturing process can be completed only through three times of mask, the mask needs to be arranged when the groove is formed, the first polycrystalline silicon is formed and the metal electrode is formed, the mask used when the source region is formed and the body contact region is formed is omitted, and cost is saved.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a manufacturing process of an SBR device in which charge coupling is realized by three masks. Background technique [0002] The fabrication process of traditional charge-coupled SBR devices is as follows: 1A to 1I shown, including the following steps: [0003] A substrate 1 is provided, an epitaxial layer 2 is formed on the substrate 1, and a thin oxide layer 3 is formed on the surface of the epitaxial layer 2, such as Figure 1A shown; [0004] A first mask is set, a trench is formed by photolithography, and the first mask is removed. The trench includes an active region trench 4-1 and a terminal region trench 4-2, such as Figure 1B shown; [0005] A field oxide layer 5 is formed in the trench, such as Figure 1C shown; [0006] Fill polysilicon and etch back to form a first polysilicon 6 in the trench, such as Figure 1D shown; [0007] A second mask 7 is set, t...

AI Technical Summary

Problems solved by technology

[0014] As we all know, the cost of setting up a mask is extremely high, and every time a mask is set up, the production cost of the entire device will greatly increase

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