Fabrication method of beam-mass structure based on laser combined anisotropic etching

Abstract

The invention provides a preparation method of a beam-mass structure based on laser combined anisotropic etching. The preparation method comprises the following steps: 1) providing a (111) silicon wafer; 2) forming a first deep groove in a back surface of the (111) silicon wafer by employing a laser machining process; 3) forming a second deep groove in a front surface of the (111) silicon wafer; 4) respectively forming a first oxide layer on a surface of the (111) silicon wafer as well as on a side surface and a bottom part of each of the first deep groove and the second deep groove; 5) forming a third deep groove in the front surface of the (111) silicon wafer; 6) respectively forming a second oxide layer on surfaces of the first oxide layers as well as on a side surface and a bottom part of the third deep groove; and 7) releasing a beam by employing a reactive ion etching process and an anisotropic etching process. The beam-mass structure is formed by employing the laser machining process and in combination with the reactive ion etching process and the anisotropic etching process, so the cost of the whole process can be reduced; and a thickness of a beam structure is determined by deep reactive ion etching performed on the front surface of the (111) silicon wafer, and the process precision is high.

Description

technical field [0001] The invention belongs to the technical field of micro-nano processing, and in particular relates to a method for preparing a beam-mass structure based on laser combined with anisotropic corrosion. Background technique [0002] Micro Electro Mechanical System technology (MEMS, Micro Electro Mechanical System) uses a process compatible with integrated circuits to realize the integration of sensors and actuators on silicon chips, which is a branch of integrated circuits. At present, the pillar products in the field of MEMS technology include acceleration sensors, micro-mechanical gyroscopes, pressure sensors, microphones, and digital projection chips. Among them, acceleration sensors and micromachined gyroscopes generally adopt a beam-mass structure, and are usually fabricated by surface micromachining or bulk micromachining technology. Since the performance of inertial devices such as acceleration sensors and micro-mechanical gyroscopes is related to ma...

AI Technical Summary

Problems solved by technology

The main reason for limiting the wide application of laser processing in sensor manufacturing is that the control accuracy of laser ablation depth is different from that of deep reactive ion etching technology, and it is difficult to maintain high control accuracy while ensuring processing efficiency

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