Device for improving etching uniformity

Abstract

The invention discloses a device for improving the etching uniformity. A rectification protective sheath is arranged in an etching chamber; the lower part of the rectification protective sheath is in a hollow cylindrical support structure; the upper part of the rectification protective sheath is an anti-corrosion ring-shaped plane structure which is sleeved on the support structure and has a certain thickness; a reaction chamber of the whole etching chamber is divided into an upper silicon wafer etching area and a lower vacuum exhaust area by the rectification protective sheath; a plasma is limited on a key area near an upper silicon wafer by the rectification protective sheath, so that a plasma control area is reduced, and the uniformity is more easy to control; in a smaller space, the concentration of the plasma is improved, so that a faster etching rate can be obtained; and the rectification protective sheath is uniformly provided with a plurality of through holes, so that after being shunted, the air at the upper part of the rectification protective sheath is pumped out by a molecular pump through two asymmetrical air outlet openings. The novel rectification protective sheath plays an air exhaust buffer effect, so that the influence of air pumping by the molecular pump on the etching uniformity is lowered.

Description

Technical field [0001] The invention relates to an etching device, in particular to a device for improving etching uniformity. Background technique [0002] With the development of integrated circuits, the integration of semiconductor devices has increased, the line width of semiconductor devices has become smaller and smaller, the control of key dimensions has become more and more important, and the requirements for etching processes have become higher and higher. The etching technique often used at present is dry etching, which is plasma etching. In dry etching, uniformity is an important indicator of the difference in the etching rate of different etching positions. Better uniformity will result in better yield, especially when the area of ​​the etched wafer increases. The control is even more important. [0003] However, such as E-max (a type of plasma etching equipment produced by Applied Materials (AMAT)) plasma etching equipment, after the process gas enters the cavity fro...

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Problems solved by technology

[0008] In view of the above existing problems, the present invention provides a device for improving the uniformity of etching, so as to improve the problem that the uniformity is difficult to control in the existing plasma etching process

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