Device and method for improving plasma etching uniformity

Abstract

The invention discloses a device and method for improving the plasma etching uniformity. The device comprises a direct-current power supply and a filter, wherein one end of the direct-current power supply is grounded, the other end of the direct-current power supply is connected with a focusing ring of a lower electrode of the plasma etching system through the filter, direct-current voltage is loaded on the direct-current power supply, the magnitude and polarity of the direct-current power supply are adjustable, and the filter is used for filtering alternating-current components in direct current. The polarity and the magnitude of the direct-current voltage are adjusted by loading direct-current voltage on the focusing ring of the lower electrode of the plasma etching system, so that the etching rate of the edge part of a wafer tends to be consistent with the etching rate of the center part of the wafer. The device is simple and easy to implement, the etching uniformity can be effectively improved, and the production efficiency is improved.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a device and method for improving plasma etching uniformity. Background technique [0002] Plasma etching is used to etch conductive and dielectric materials during semiconductor wafer fabrication. In the semiconductor process, the etching uniformity directly affects the yield of the equipment. Therefore, the etching uniformity has become an important requirement and one of the important parameters to measure the performance of the equipment. [0003] With the development of integrated circuits, the diameter of wafers is getting larger and larger, and the critical dimensions are getting smaller and smaller. The designed structure is getting closer to the edge, ensuring the uniformity of critical dimensions in the entire wafer, and becoming more and more difficulty. For example, as the wafer size increases from 200mm to 300mm, the edge loss of the wafer should be less tha...

AI Technical Summary

Problems solved by technology

But at present, a single plasma etching equipment needs to be matched with a focus ring of a material or a structure, and the cavity needs to be replaced to replace the focus ring, which affects the stability of the process.

For the same plasma etching device, when processing wafers, due to the diversification of process requirements, when the composition of the etching gas changes, the etching rate at the edge of the processed wafer will be higher or lower, and it is difficult to pass Adjustment of process component parameters to obtain good edge uniformity

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