Pallet system used for plasma dry etching

Abstract

The invention relates to the technical field of semiconductor processing and provides a pallet system used for plasma dry etching, which introduces a grapheme material or grapheme composite material layer to improve the surface heat dissipation capability and the temperature uniformity of a wafer. The pallet system comprises an aluminum pallet, helium hole, a sealing ring, a cover plate and the embedded grapheme material (or grapheme composite material) layer high in heat conductivity. The pallet system has the advantages and active effects that: the high-heat-conductivity grapheme material or grapheme composite material are used in the pallet system used for the r plasma dry etching, the instant heat dissipation capability of the wafer in the etching process is substantially improved, the temperature uniformity of the surface of the wafer is conveniently controlled, the qualified rate of etched products is improved, and the operation window of the etching process is enlarged.

Description

technical field [0001] The invention relates to the technical field of semiconductor processing, in particular to a tray system for plasma dry etching that improves the heat dissipation capability of the wafer surface and improves temperature uniformity by introducing high thermal conductivity materials. Background technique [0002] In the process of semiconductor processing, especially in the dry plasma etching (ICP) process, a tray system is generally used to fix, support and transfer the wafer (Wafer) to avoid movement or misalignment of the wafer during the process. In addition, during the whole process of etching the wafer, the tray acts as the lower electrode of the electrode system. By connecting to a radio frequency (RF) power supply, the RF power supply will form a DC bias voltage (DCBias) on the wafer. This facilitates the etching reaction of the plasma to the wafer. At the same time, the tray system controls the temperature of the wafer to control the uniformity...

AI Technical Summary

Problems solved by technology

[0005] (1) The thermal conductivity of He gas is only 0.144W / m.K, and the thermal conductivity of aluminum is 237W / m.K. The existing problem is that the temperature of the wafer surface will continue to rise during the high bias power etching operation. When the surface When the temperature exceeds the glass transition temperature (Tg) of the photoresist mask, the photoresist will be deformed or even burnt, resulting in abnormal etching;

[0006] (2) In the etching process, when the sealing effect is not good due to the loading link, He gas leakage will cause the local temperature of the wafer to be too high, thereby causing the wafer surface pattern to be distorted. The link and sealing requirements are very high, and the adjustable window is small;

[0007] (3) The gap between the wafer and the aluminum tray is required to be very narrow, so the volume filled with He gas is limited, which is not conducive to the sufficient heat conduction of He gas to the wafer, resulting in high surface temperature and uneven distribution of the wafer

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