Method for forming a shallow trench isolation structure

Abstract

A method for forming a shallow trench isolation structure includes: providing a substrate; etching the substrate to form a shallow trench, forming a sharp corner at the top sidewall of the shallow trench; forming dielectric material at the shallow trench; then performing annealing treatment in an inert gas atmosphere to smooth the sharp corner, wherein the molecular mass of the gas in the gas atmosphere is greater than or equal to that of argon gas. Annealing treatment changes sharp corner into a rounded angle, and the rounded angle can avoid stress concentrating. When a current passing through a semiconductor device, a high electric field is not concentrated in the rounded position, thereby decreasing leakage current, avoiding breakdown and narrow width effect of the shallow trench isolation structure.

Description

technical field [0001] The present invention relates to the field of semiconductor technology, and in particular, to a method for forming a shallow trench isolation structure. Background technique [0002] In the prior art, semiconductor device isolation using Shallow Trench Isolation (STI) technology has become a conventional technology. [0003] Figure 1 ~ Figure 4 It is a schematic cross-sectional structure diagram of a method for manufacturing a shallow trench isolation structure in the prior art. refer to figure 1 , a silicon oxide layer 101 and a silicon nitride layer 102 located on the silicon oxide layer 101 are formed on the substrate 100 . refer to figure 2 , a patterned photoresist layer 103 is formed on the silicon nitride layer, and the patterned photoresist layer 103 is used as a mask to etch the silicon nitride layer and the silicon oxide layer. An opening 104 is formed therein, and the opening 104 exposes the surface of the substrate 100 . refer to ...

AI Technical Summary

Problems solved by technology

When the current is passed through the semiconductor device, the high electric field is easy to concentrate at the defect position, resulting in increased leakage current, breakdown of the shallow trench isolation structure, and narrow width effect (Narrow Width Effect)

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