Manufacturing method for shallow trench isolation structure

Abstract

The invention provides a manufacturing method for a shallow trench isolation structure. The method includes the following steps: covering a semiconductor substrate with an oxide layer and a nitride layer sequentially; carrying out exposure and etching process to form a shallow trench figure; depositing an isolation layer to fill the shallow trench figure; carrying out flattening processing on the isolation layer, and leaving part of the isolation layer; and removing the remaining isolation layer by adopting the method of wet etching, and then removing the nitride layer. According to the manufacturing method for the shallow trench isolation structure, in the process of flattening processing, the nitride layer is not contacted, flattening can be achieved by adopting common lapping fluid, cost of the lapping fluid is reduced, and meanwhile, the phenomena of indentation and corrosion caused by chemical and mechanical lapping are avoided due to the fact that the remaining isolation layer on the nitride layer is removed by using the method of wet etching.

Description

technical field [0001] The invention relates to the field of semiconductor integrated circuits and its manufacture, in particular to a method for manufacturing a shallow trench isolation structure. Background technique [0002] In recent years, with the development of semiconductor integrated circuit manufacturing technology, the number of components contained in the chip has been increasing, and the size of the components has been continuously reduced due to the improvement of integration. However, no matter how the device size is reduced, there must still be proper insulation or isolation between the various devices in the chip in order to obtain good device properties. The technology in this area is generally called Device Isolation Technology (Device Isolation Technology). More chip area to accommodate more components. [0003] Among various component isolation technologies, the local silicon oxidation method (LOCOOS) and the shallow trench isolation structure (Shallow...

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Problems solved by technology

[0005] The traditional production method uses relatively expensive high-selection ratio polishing fluid to grind the silicon dioxide layer for planarization, which is relatively expensive, and an appropriate amount of over-grinding must be added after grinding to the silicon nitride surface to ensure that the silicon nitride surface is free of damage. Silicon oxide remains, resulting in a depression (Disshing) on ​​the silicon oxide surface in the large-area pattern area 103, and an erosion (Erosion) phenomenon in the silicon oxide in the high-density pattern area 104, which weakens the planarization effect and ultimately reduces the shallow trench isolation device. Isolation

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