Preparation method of MEMS microbridge structure

Abstract

The invention provides a preparation method of an MEMS microbridge structure. The method comprises the following steps: 1. preparing a reflecting layer on the surface area of a substrate; 2. preparing a sacrificial layer on the surface area of the reflecting layer, etching a supporting hole on the sacrificial layer; 3. successively preparing a supporting layer, a sensitive layer and a medium layer on the surface area of the sacrificial layer; 4. patterning the inside of the supporting hole and the bridge surface area, forming a contact hole; 5. depositing a metal electrode layer and metal copper on the surface area of the medium layer, flattening metal copper until the medium layer; and 6. removing the sacrificial layer and forming the finished microbridge structure. The preparation method uses the copper pillar instead of the traditional aluminum pillar and utilizes the copper chemical-mechanical polishing method to realize the self-alignment patterning of the metal electrode so that the planarization of the microbridge structure can be realized, the connection resistance can be effectively reduced and the complexity of the process can also be reduced.

Description

technical field [0001] The invention relates to a MEMS micro-bridge structure, in particular to a method for preparing the MEMS micro-bridge structure. Background technique [0002] Micro-Electro-Mechanical System (MEMS) technology can integrate mechanical components, drive components, electronic control systems, digital processing systems, etc. into a micro-system as an overall unit. This kind of MEMS can not only collect, process and send information or instructions, but also take actions independently or according to external instructions according to the acquired information. It uses the combination of microelectronics technology and micromachining technology (including micromachining of silicon body, micromachining of silicon surface, LIGA and wafer bonding and other technologies) to manufacture various sensors with excellent performance, low price and miniaturization. Actuators, drives and microsystems. It has many advantages such as tiny, intelligent, executable, in...

AI Technical Summary

Problems solved by technology

However, this process has some obvious disadvantages. Especially in the process of making aluminum pillar metal, the etching of aluminum requires the process to stop on the sensitive material layer. The process steps are complicated and the process control is difficult, resulting in a relatively large subsequent process window. Small, not conducive to the subsequent process

In addition, due to the high resistivity of aluminum, the electrical characteristics of aluminum pillars are also poor.

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