Deep silicon etching method

Abstract

The invention discloses a deep silicon etching method which comprises the following steps: (1) preparing a graphic photoresist mask on a silicon chip surface; (2) performing deep inductively coupled plasma dry etching of the silicon chip, wherein the etching is divided into several phases, each etching phase is completed in a inductively coupled plasma machine, and is completed through alternate circular processing of three steps of passivation, bombardment, and etching, and with the increase of the etching depth, the bombardment intensity in the bombardment step of each etching phase increases gradually. The method of the invention effectively solves the problems of difficult control of sidewall verticality and roughness, and difficult realization of large etching depth in the prior art, both improves the etching efficiency and increases the selection ratio or photoresist, and is high in etching groove sidewall verticality, low in roughness, and large in etching depth.

Description

technical field [0001] The invention belongs to the technical field of plasma processing, and more specifically relates to a deep silicon etching method. Background technique [0002] Micro-electro-mechanical systems (MEMS) are more and more widely used in the fields of automobiles and consumer electronics, and the development of MEMS technology based on microelectronics technology is particularly rapid. The introduction of high-aspect-ratio silicon etch techniques into microelectronics processes has enabled a range of novel sensor and actuator structures. Compared with the surface processing technology, the bulk silicon structure obtained by the deep silicon etching process has a larger movable sensitive mass, a larger detection capacitance, and higher performance indicators such as device resolution and sensitivity. However, as a key step in the processing of bulk silicon MEMS devices, it is difficult to control the verticality and roughness of the sidewalls in the existi...

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Problems solved by technology

[0003] In view of the above defects or improvement needs of the prior art, the present invention provides a deep silicon etching method, which effectively solves the problems in the prior art that the verticality and roughness of the sidewall are difficult to control and the large etching depth is difficult to achieve. While improving the etching efficiency, the selectivity ratio of the photoresist is improved, the verticality of the side wall of the etching groove is high, the roughness is small, and the etching depth is large

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