Etching method of etching hole having inclined side wall

Abstract

The invention provides an etching method of an etching hole having an inclined side wall. In the etching method, an etching stopping layer, an etching target layer and a mask layer are formed in sequence on a substrate used for being etched, after the substrate to be etched is put in a plasma reaction chamber, the mask layer is used as a mask, and the target material layer is etched by a first etching process, thereby forming an etching hole vertical to the etching stopping layer at the lower side; the mask layer is etched and removed by a second etching process; the target material layer after removing the mask layer is etched by a third etching process, till a corrected etching hole is formed, and an included angle formed by the side wall of the corrected etching hole and a plane of the etching stopping layer at the lower side is smaller than 80 degrees.

Description

technical field [0001] The invention relates to the field of plasma processing, in particular to an etching method for etching a silicon substrate to obtain an etching hole with inclined side walls. Background technique [0002] In the field of semiconductor manufacturing technology, in the fields of MEMS (Micro-Electro-Mechanical Systems, Micro-Electro-Mechanical Systems) and 3D packaging technology, it is usually necessary to perform deep etching of silicon and other materials. For example, in the crystalline silicon etching technology, the deep silicon etching hole (Through-Silicon-Via, TSV) has a depth of hundreds of microns, and its aspect ratio is even much greater than 10. It is usually etched by deep reactive ion etching. etched silicon formation. Said silicon material is mainly monocrystalline silicon. After the etching is completed, conductive materials such as copper are filled into the holes or grooves formed by etching. The filling method can be chemical vapor...

AI Technical Summary

Problems solved by technology

Precisely controlling the amplitude and shape of mask layer hole expansion in each cycle also requires precise control of all processing parameters, so each step in the vertical-expanding opening cycle of this patent requires precise control, which is not only slow but also difficult to control

At the same time, this method of etching will form a lot of stepped rings on the sidewall, so the smoothness of the sidewall is also very poor. To obtain the final smooth sidewall, additional steps are needed to eliminate these steps, which further reduces the overall processing efficiency

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