Method for reducing plasma etcher cavity pollution in back hole process

Abstract

The invention discloses a method for reducing plasma etcher cavity pollution in a back hole process. The method comprises the steps of sputtering or evaporating a metal mask layer on the back of a SiC substrate; enabling the metal mask layer to be coated with photoresist, and drying the photoresist; performing photoetching on the photoresist to form a photoresist pattern; utilizing the formed photoresist pattern to corrode the metal mask layer, and forming a metal mask graph; performing plasma bombardment on the back of the SiC substrate of the formed metal mask graph in a plasma etcher, sputtering the photoresist on the metal mask layer to an inner wall of a cavity of the plasma etcher, and forming a photoetching layer on the inner wall of the cavity of the plasma etcher; utilizing the formed metal mask graph to etch the SiC back in the plasma etcher, and forming a back hole until the back hole is communicated with SiC front source metal. By utilizing the method, the pollution to the inner wall of the plasma etcher cavity caused by a metal mask in the back hole process is reduced, and using efficiency of the plasma etcher is improved.

Description

technical field [0001] The invention relates to the technical field of backhole processing of GaN and SiC microwave devices, in particular to a method for reducing the pollution of the cavity of a plasma etching machine in the backhole process, which can effectively reduce the impact of metal masks on plasma etching in the backhole process. The pollution of the inner wall of the etching machine cavity is improved, and the efficiency of the plasma etching machine is improved. Background technique [0002] The back hole technology realizes the grounding of the source end, shortens the grounding distance of the device and the circuit, effectively reduces the series inductance of the device grounding end, and thus improves the power characteristics of the device in the microwave state, which is the key technology of GaN microwave devices. [0003] Back hole etching often uses metal as a mask, such as Ni, Al, etc., and ordinary photoresists are difficult to use. The steps of conv...

AI Technical Summary

Problems solved by technology

[0008] In the process of etching the back of SiC with a metal mask pattern to form a back hole, due to the bombardment of the plasma, the metal in the metal mask is sputtered and deposited on the inner wall of the plasma etching machine, such as Figure 5 As shown, the subsequent treatment of the inner wall of the plasma etching machine cavity is extremely complicated, and it is difficult to

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