Method for improving spacer shape

Abstract

The invention discloses a method for improving a spacer shape in the production of a semiconductor device. The method comprises steps of: depositing a spacer film, performing plasma anisotropic bombardment, re-depositing the spacer film, and then performing the spacer etching. The method utilizes plasma anisotropic bombardment before etching the spacer of the semiconductor device, and bombards thedevice in the vertical direction by plasma. The contact area between the spacer and the plasma is different from that between the top of the polycrystalline silicon and the plasma in the vertical direction, thereby increasing an etching selection ratio between the spacer and a nitride film on the top of the polycrystalline silicon, and achieving less shoulder loss and a more straight shape of thespacer.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a method for improving the shape of the isolation side wall. Background technique [0002] In the manufacturing technology of semiconductor integrated circuits, etching of spacers is one of the key steps. With the development of integrated circuit technology, the sensitivity and requirements of semiconductor device performance to spacer uniformity are further increased. [0003] However, the etching of the isolation sidewall has poor control over the edge of the sidewall, making it very difficult to control the thickness of the edge sidewall, and the etching rate of the isolation sidewall is inconsistent. This difference is due to the poor uniformity of the sidewall surface and the isolation The sidewall morphology is poor, which in turn leads to poor overall device uniformity. figure 1 It is a manufacturing method for isolating sidewalls of semiconductor devices in t...

AI Technical Summary

Problems solved by technology

[0004] The existing technology is to adjust the morphology of the isolation sidewall after the main etching. The only way to fine-tune the morphology of the sidewall is to remove the silicon nitride on the wafer surface through over-etching. Due to the film quality of the poly top and the sidewall With the same limitation, when the sidewall CD is adjusted by over-etching, the top of the Poly will also produce obvious shoulder loss, and over-etching may even cause damage to the Poly.

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