Deep silicon etching method

Abstract

The invention discloses a deep silicon etching method, which comprises the following steps of: performing thin film deposition on silicon to be etched, and forming an oxide thin film layer on the silicon to be etched; forming a first photoresist layer on the oxide film layer, and photoetching the first photoresist layer to obtain a photoresist layer with a first preset pattern on the oxide film layer; etching the to-be-etched silicon to remove the oxide film layer at the first preset pattern so as to obtain the to-be-etched silicon with the first preset pattern; forming a second photoresist layer on the to-be-etched silicon with the first preset pattern, and photoetching the second photoresist layer to obtain a photoresist layer with a second preset pattern on the oxide film layer; the side, where the second preset pattern is formed, of the to-be-etched silicon is etched, so that a first function area is formed at the first preset pattern, and a second function area is formed in the second preset pattern except the first preset pattern, etching of different depths can be achieved through one-time etching, and the method has the advantages of being easy to spin glue and high in exposure precision.

Description

technical field [0001] The present application relates to the technical field of semiconductor etching, in particular to a deep silicon etching method. Background technique [0002] Forming silicon cavities or silicon grooves with different step depths by multiple deep silicon etching is an important process in micro-nano processing technology. In the prior art, silicon wafers of different depths are etched by multiple times of uniform glue, photolithography, and deep silicon etching. However, when the silicon etching depth is relatively deep for the first time (such as 100 Micron or more), the glue spraying process is usually used to uniform the glue, but when using this glue spraying process for exposure, the accuracy is difficult to guarantee, and even, when a relatively deep cavity or groove appears on the silicon wafer, it will become It is extremely fragile, and it is easy to generate debris when it is subjected to photolithography or etching processes. [0003] Ther...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the problems of the prior art, the embodiment of the present application provides a technical solution of a deep silicon etching method to solve the problems of difficulty in distributing glue at high steps, poor exposure precision and waiting time when the silicon to be etched is etched at different depths. Etching silicon after a deep silicon etch and then etching again is easy to fragment and other problems. The technical solution is as follows:

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