Method for forming multiple silicon trenches on MEMS (Micro Electro Mechanical Systems) sealing-cap silicon chip and etching mask structure thereof

Abstract

A multi-silicon trench forming method and an etching mask structure thereof for an MEMS sealing cap silicon chip. The method comprises: step S11, providing an MEMS sealing cap silicon substrate (100); step S12, forming n overlapped mask layers (101, 102, 103) on the MEMS sealing cap silicon substrate (100), and after forming each mask layer, photoetching and etching the mask layer and all the other mask layers beneath same, so as to form a plurality of different etching windows (D1, D2, D3); step S13, etching the MEMS sealing cap silicon substrate using the current uppermost mask layer and a layer of mask material beneath same as a mask; step S14, removing the current uppermost mask layer; and step S15, repeating steps S13 and S14 until all the mask layers are removed. The present invention can form a plurality of deep trenches with a high aspect ratio on an MEMS sealing cap silicon chip using a conventional semiconductor process, thereby avoiding the problem that the conventional spin coating cannot be conducted on a sealing cap silicon chip with a deep trench using a photoresist.

Description

technical field [0001] The invention relates to a method for forming multiple silicon grooves of a MEMS cap silicon chip and an etching mask structure thereof, in particular to a method for forming a plurality of silicon grooves with different groove depths on a MEMS cap silicon chip. Background technique [0002] Micro Electro Mechanical Systems (MEMS, Micro Electro Mechanical Systems) technology is known as a revolutionary high-tech in the 21st century. Its development began in the 1960s. It is an ingenious combination of microelectronics and micromechanics. It has been developed in recent years. A new type of interdisciplinary technology, which will have a revolutionary impact on human life in the future. [0003] The basic technologies of MEMS mainly include silicon anisotropic etching technology, silicon / silicon bonding technology, surface micro-mechanical technology, LIGA technology, etc. The above-mentioned technologies have become indispensable core technologies for ...

AI Technical Summary

Problems solved by technology

However, when the aspect ratio of the silicon groove is greater than 2 or the groove depth is greater than 3um, the previously formed deep groove will cause the subsequently formed photoresist to be trapped in the deep groove, resulting in the inability to obtain the silicon wafer by using the conventional coating process. Uniform glue thickness plane, so that the subsequent photolithography process cannot be carried out normally

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