Method for improving small-spherical defect in manufacture process of shallow trench isolation substrate

Abstract

The invention provides a method for improving a small-spherical defect in a manufacture process of a shallow trench isolation substrate, comprising the following steps of: forming shallow trenches on a semiconductor substrate; cleaning the semiconductor substrate with the formed shallow trenches by using a cleaning solution to remove a silica oxide film formed on a shallow trench structure, and then cleaning the residual cleaning solution and reaction byproducts by using de-ionized water; and repeating the cleaning step until the silica oxide film is removed or a required removing amount is achieved, wherein the thickness of the silica oxide removed by the cleaning solution every time is smaller than 15 angstroms. According to the method for improving the small-spherical defect in the manufacture process of the shallow trench isolation substrate, the small-spherical defect formed on an STI (Shallow Trench Isolation) structure when the oxide film is removed by hydrofluoric acid is improved, and therefore the yield is increased.

Description

technical field [0001] The invention relates to the field of integrated circuit manufacturing, and in particular to a method for improving small spherical defects in the shallow trench isolation substrate manufacturing process in wet etching. Background technique [0002] Shallow Trench Isolation (STI) is a general isolation method used in semiconductor technology below 0.25um. The advantage of this isolation method is that it has a good isolation effect and occupies a small area. [0003] In the technical field of integrated circuit manufacturing, the steps of forming shallow trench isolation include: forming shallow trenches on a semiconductor substrate; filling the shallow trenches with spacers; and planarizing the shallow trenches after filling the spacers. Wherein, the step of filling the spacer into the shallow trench includes: cleaning the semiconductor substrate on which the shallow trench has been formed; forming a pad oxide layer in the shallow trench; depositing a...

AI Technical Summary

Problems solved by technology

Under the condition that the amount of removal remains unchanged and the concentration of hydrofluoric acid is changed, small balls will still appear, and such small balls cannot be removed with deionized water and SC1 (mixed solution of deionized water: hydrogen peroxide: ammonia water), if it Appearing in areas with high pattern density, it will partially cover the STI trench, so that subsequent films cannot be deposited into the trench, forming voids, resulting in loss of yield

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