Manufacturing method of shallow trench isolation structure

Abstract

The invention discloses a manufacturing method of a shallow trench isolation structure. The manufacturing method comprises the steps of: forming a hard mask layer on a substrate, and forming a shallowtrench through etching, wherein the hard mask layer comprises a pad oxide layer and a pad nitride layer located on the pad oxide layer; forming a barrier layer in the shallow trench and on the hard mask layer; etching a part of the barrier layer by using a first dry etching process until the part of the barrier layer stops at the pad nitriding layer; longitudinally and laterally etching the hardmask layer and a part of the residual barrier layer by using a second dry etching process until the hard mask layer and a part of the residual barrier layer are stopped on the substrate to form a shallow trench with a fillet, wherein the bias power adopted by the second dry etching process is 0-98W; and removing the remaining barrier layer in the shallow trench with the fillets by using a third dry etching process. Based on the method, excellent lateral etching efficiency is ensured, and damage to silicon is avoided.

Description

technical field [0001] The invention belongs to the technical field of integrated circuits, in particular to a method for manufacturing a shallow trench isolation structure. Background technique [0002] The Shallow Trench Isolation (STI) process is an important process for integrated circuit functions, which can prevent current leakage between adjacent semiconductor devices and play a role in other electrical properties. At present, in order to avoid the problem of tip discharge in the process of manufacturing shallow trench isolation structures by etching, it is often necessary to passivate the corners of shallow trench isolation structures to avoid potential problems, such as electrical properties and unstable yields. situation occurs. [0003] At present, the passivation corner of the shallow trench isolation structure is generally passivated by wet etching the silicon oxide and silicon nitride on the substrate laterally. However, when the silicon oxide is etched with h...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a method for manufacturing a shallow trench isolation structure, which solves the problem of damage to the substrate and the instability of electrical properties and yield when the existing shallow trench isolation structure is formed by etching. The manufacturing method is simple and convenient to operate

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