Method for manufacturing shallow trench isolation structure

Abstract

The invention provides a method for manufacturing a shallow trench isolation structure. The method comprises the following steps: forming a pad oxide layer and a corrosion barrier layer on a semiconductor substrate in sequence; etching the corrosion barrier layer, the pad oxide layer and the semiconductor substrate to form a shallow trench; carrying out laser heat treatment on the semiconductor substrate in the shallow trench, and introducing oxygen into the substrate to form a lining oxide layer; filling insulating oxide layers in the shallow trench; removing the corrosion barrier layer and the pad oxide layer until the semiconductor substrate is exposed so as to form the shallow trench isolation structure. The method improves the quality of the subsequent lining oxide layer, reduces leakage current, and improves the quality of semiconductor devices.

Description

technical field [0001] The invention relates to the manufacturing field of semiconductor devices, in particular to a manufacturing method of a shallow trench isolation structure. Background technique [0002] As the size of integrated circuits decreases, the devices that make up the circuits must be placed more densely to fit the limited space available on the chip. Since current research is devoted to increasing the density of active devices per unit area of ​​a semiconductor substrate, effective insulating isolation between circuits becomes more important. The methods for forming isolation regions in the prior art mainly include local oxidation isolation (LOCOS) process or shallow trench isolation (STI) process. The LOCOS process is to deposit a layer of silicon nitride on the surface of the wafer, and then perform etching to oxidize and grow silicon oxide in part of the recessed area, and the active device is generated in the area determined by the silicon nitride. For ...

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Problems solved by technology

[0008] In the existing process of forming a shallow trench isolation structure, since the etching gas or liquid will generate defects on the inner wall of the shallow trench when etching to form the shallow trench, it will affect the quality of the subsequently formed lining oxide layer, especially in the shallow trench The stress at each corner inside will increase, resulting in leakage current phenomenon

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