Cavity cleaning method of plasma etching device

Abstract

The invention discloses a cavity cleaning method of a plasma etching device. The plasma etching device comprises a reaction cavity, a gas inlet unit and a gas exhaust unit. The cavity cleaning method includes the steps that first process gas is led into the plasma etching device to wash the gas inlet unit, and at least parts of reaction by-products on the inner wall of the gas inlet unit are peeled off; second process gas is led into the plasma etching device to form plasmas of the second process gas, and the second process gas reacts with the peeled-off reaction by-products and reaction by-products on the inner wall of the reaction cavity so as to clean the inner wall of the reaction cavity; the pressure of the second process gas is increased, so that the plasmas of the second process gas reacts with the unpeeled-off reaction by-products in the gas inlet unit so as to clean the inner wall of the gas inlet unit. The cavity cleaning method can effectively reduce the risk of wafer center agglomeration defects caused due to the fact that residues of the gas inlet unit deposit and fall.

Description

technical field [0001] The invention relates to the technical field of semiconductor processing, in particular to a cavity cleaning method of a plasma etching device. Background technique [0002] In recent years, with the development of semiconductor manufacturing technology, the requirements for the integration and performance of components are getting higher and higher. Plasma etching technology is playing a pivotal role in the field of semiconductor manufacturing by exciting the plasma formed by etching gas. role. Generally speaking, in a plasma etching device, the plasma is generally formed by radio frequency excitation of the etching gas discharged from the inlet unit at the top of the reaction chamber, and the plasma bombards the wafer on the chuck, thereby realizing Etching of the wafer. [0003] figure 1 A schematic structural diagram of a plasma etching device is shown. The plasma processing device includes a reaction chamber 1, and an air inlet unit 2 is conne...

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Problems solved by technology

Traditionally, when cleaning the reaction chamber, it is mostly carried out in a low vacuum pressure environment. However, the vacuum pumping device usually has a strong pumping capacity, and the plasma of the cleaning reaction gas may not fully react with the by-products. It is quickly drawn away from the reaction chamber by the vacuum pumping device, thereby reducing the cleaning effect; and the air inlet unit located at the far end of the reaction chamber is more difficult to be completely cleaned due to the longer inlet path, resulting in by-products on the inner wall of the air inlet unit Residual overlay, increasing the risk of agglomerated defects falling in the center of the wafer and resulting in lower product yields

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