A method for avoiding gate polysilicon etching dent defect

Abstract

The invention provides a method for avoiding the etching dent defect of grid polycrystalline silicon. The method comprises the following steps of: (1), forming a first hard mask group sub-layer on a polycrystalline silicon layer, wherein the first hard mask group sub-layer is a constituent part used for etching a hard mask of the polycrystalline silicon layer; and the first hard mask group sub-layer has the first thickness; and (2), forming a second hard mask group sub-layer on the first layer, wherein the second hard mask group sub-layer is another constituent part used for etching the hard mask of the polycrystalline silicon layer; the second hard mask group sub-layer has the second thickness; and the second thickness is set according to the first thickness. In the method for avoiding the etching dent defect of the grid polycrystalline silicon provided by the invention, the thickness of the second layer in the hard mask on the polycrystalline silicon layer is dynamically adjusted according to the thickness of an oxide layer in the hard mask on the polycrystalline silicon layer; and, the etching dent defect of the grid polycrystalline silicon can be effectively avoided in a condition that the technological operation does not need to be changed.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, and more specifically, the invention relates to a method for avoiding pitting defects of gate polysilicon etching. Background technique [0002] In the 0.15 process, after the polysilicon is etched, pit defects are sometimes found on the etched polysilicon. Specifically, the polysilicon etching method according to the prior art generally includes: a step of forming a photoresist pattern, a step of forming a hard mask pattern, and a step of forming a polysilicon pattern. [0003] figure 1 A schematic view schematically showing the photoresist pattern forming steps of the polysilicon etching method according to the prior art. like figure 1 As shown, an oxide layer 21, a SION layer 22 (the oxide layer 21 and the SION layer 22 form a hard mask) and a photoresist layer 30 are sequentially formed on the polysilicon layer 10, and a photoresist pattern is formed. figure 2 A schematic view ...

AI Technical Summary

Problems solved by technology

[0004] However, as mentioned above, in some cases, dent defects will be found on the etched polysilicon, and this defect will lead to product failure, reduce yield, and cause waste

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