Method for overcoming defects of silicon chip with STI and method for constructing STI on silicon chip

Abstract

The invention discloses a method for overcoming defects of a silicon chip with STI (Shallow Trench Isolation). A method for constructing STI on the silicon chip comprises the following steps of: depositing a pad oxides layer (103) and a silicon nitride layer (104) on a silicon substrate (101) of the silicon chip sequentially, covering the surface of the silicon chip by using photoresist, performing pattern transferring, and etching silicon nitride, pad oxide and the silicon chip by using the photoresist as a mask to construct an STI structure of which the bottom part is positioned in the silicon substrate. The method is characterized in that: After the silicon nitride layer (104) is deposited on the silicon chip and before the surface of the silicon chip is covered by the photoresist and pattern transferring is performed, the method comprises following step of: performing first annealing on the silicon chip to remove the internal stress of the silicon. The invention also discloses other methods for overcoming the defects of silicon chip with STI and methods for constructing the STI on the silicon chip. The technical scheme can effectively remove the internal stress of the silicon chip, thereby avoiding micro cracks in corners of the STI caused by internal stress and overcoming the defects of the surface of the silicon substrate.

Description

technical field [0001] The invention relates to the technical field of semiconductor integrated circuit processing, in particular to a method for suppressing defects of a silicon wafer with a shallow trench isolation (Shallow Trench Isolation, STI) structure and a method for constructing an STI on a silicon wafer. Background technique [0002] In the manufacturing process of semiconductor integrated circuits, it is often necessary to form a shallow trench isolation (Shallow Trench Isolation, STI) structure on a silicon wafer by etching. Such as figure 1 As shown, the silicon substrate 101 is composed of single crystal silicon, and the single crystal silicon is also called an active area (Active Area, AA). The concave portion in the center of the upper surface of the silicon substrate 101 is a shallow trench isolation trench formed by etching. Corners 102 are formed between the two sidewalls of the shallow trench isolation trench and the silicon substrate 101, namely figur...

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Problems solved by technology

In addition, irregular surface defects also appear on the surface of the silicon substrate 101 near the corner region 102

The aforementioned microcracks as well as surface defects of the silicon substrate can seriously affect the performance of semiconductor circuits

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