A Polysilicon Etching Method for Eliminating Damage in Active Region

Abstract

The invention discloses a polycrystalline silicon etching method for eliminating the active region damage, and relates to the field of semiconductor manufacturing. The method includes the steps that a light resistor serves as a mask film, and the carbon tetrafluoride gas is adopted to conduct etching on a part of an antireflective coating; the light resistor serves as the mask film, and an etching way is selected and adopted to conduct etching on the residual antireflective coating; the light resistor serves as the mask film, and plasma is adopted to conduct etching on a hard mask film layer and polycrystalline silicon to form a polycrystalline silicon gate, so that the active region damage is eliminated. According to the polycrystalline silicon etching method, in the polycrystalline silicon etching process, the antireflective coating etching is divided into ordinary etching and selection ratio etching, so that the low-density active region damage, caused by image defects and polycrystalline silicon etching is avoided, and the performance of a device is improved, and the yield of the device is increased.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a method for etching polysilicon in low-density active regions. Background technique [0002] In the design of semiconductor devices, according to the requirements of different device functions, there will be high-density active area (AA dense) F area and low-density (ISO) active area F. In the area where the active area F is particularly sparse, there will be large The shallow trench (STI) E of the block, because chemical mechanical polishing (CMP) has a faster polishing rate on the large shallow trench E, after chemical mechanical polishing, the shallow trench E will be much lower than the active area F, A step height is formed, and this part of the height difference will be continuously transmitted during the deposition of polysilicon D and the deposition of silicon oxide hard mask, but due to the nature of the anti-reflective coating (BARC) B itself and the nature o...

AI Technical Summary

Problems solved by technology

[0008] The invention aims to solve the problem of damage to the low-density active region caused by polysilicon etching caused by pattern defects, thereby providing a technical solution for a polysilicon etching method that eliminates damage to the active region

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