Wet releasing method for silicon-based MEMS device by using KOH solution

Abstract

The invention provides a wet releasing method for a silicon-based MEMS device by using a KOH solution. The silicon-based MEMS device has a silicon substrate, and the upper surface of the silicon substrate has a prepared circuit structure layer. The method comprises the following steps: subjecting the lower surface of the silicon substrate to mechanical polishing, wherein a mechanical damage layer is formed on the lower surface of the silicon substrate; covering a photoresist on the circuit structure layer at first, then removing the mechanical damage layer by using a silicon etching solution and removing the photoresist; allowing a membrane resisting corrosion by the KOH solution to grow on the lower surface of the silicon substrate, on which the mechanical damage layer has been removed, and enabling the membrane to form a pattern; and finally, using the KOH solution heated in a water bath to complete wet releasing. According to the invention, conventional equipment is used, process flow is simple, process time is saved, and production cost is low; and since the wet releasing method for the silicon-based MEMS device by using the KOH solution is compatible with a traditional micro machining process, production efficiency is further improved.

Description

technical field [0001] The invention belongs to the micromechanical system (MEMS) processing technology in the field of semiconductor technology, and in particular relates to a method for releasing a silicon-based MEMS device by a wet method using KOH solution. Background technique [0002] Micro-mechanical systems (MEMS) technology originated in the late 1980s and is based on microelectronics technology. It has become a hot spot in today's international high-tech competition. Due to the excellent properties of silicon material itself and its compatibility with very large scale integration (VLSI), the micromachining technology of bulk silicon has become a key part of the MEMS process. Silicon etching technology is the most basic and critical technology in micromachining, and the wet etching of silicon with potassium hydroxide solution (KOH solution) is a key technology in silicon substrate processing, which has been widely used in In the cavity structure of silicon-based co...

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Problems solved by technology

But that will increase the CMP equipment, which will increase the cost, complicate the process, and prolong the process time

[0005] Therefore, the existing technology is difficult to balance between saving time and ensuring quality, and the production efficiency cannot be improved.

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