Air flow distribution equalized etching apparatus

Abstract

The related etching device in semiconductor wafer processing comprises a reaction chamber and a lower electrode supporting device composed by even symmetrical-distributed connecting sleeves. The benefits of this invention include: well symmetry of the airflow upper the wafer, little effect to the upper airflow, good acceleration function to uniform field formed by plasma, and better evenness for chemical reaction speed and etching rate.

Description

technical field [0001] The invention relates to the technical field of microelectronics, in particular to an etching device in semiconductor wafer processing. Background technique [0002] The plasma etching machine mainly works by using the physical and chemical reactions of the plasma on the wafer. The uniformity of wafer etching is an extremely important index of the etching process, and closely related to this index is the gas flow field formed after the chemical gas enters the reaction chamber. The symmetry of the gas flow field relative to the center of the wafer is an inevitable requirement of the etching process, and is also a key technology that must be considered in the overall design of the etching machine reaction chamber. The gas flow field is mainly related to the gas injection device, the lower electrode device, and the air extraction device (molecular pump). Explanation of related technical terms: Airflow field: Since the plasma etching machine needs to mai...

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Problems solved by technology

However, because the supporting arm 3a has certain strength requirements and the inner cavity needs to pass through various electrical and mechanical pipelines such as the electrode rod 3b, the lower electrode pipeline 3c, etc., the volume is relatively large

As shown in Figure 3, the width of the lower electrode support arm 3a is relatively large, which inevitably hinders the airflow and forms a barrier on the path of the airflow, thereby affecting the symmetry of the airflow. figure 2 Among them, the gas flow encounters a barrier at the gas flow 4a, but the gas flow flows smoothly at the gas flow 4b. The gas flow at these two places is not uniform, and the gas flow is not uniform near the edge of the wafer 1, which is not conducive to the uniformity of the plasma.

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