MEMS (micro-electromechanical system) and IC (integrated circuit) monolithical integration method

Abstract

The invention discloses an MEMS and IC monolithical integration method. The method comprises the following steps: 1, completing all IC technologies except a metal interconnection technology on a substrate, and sequentially depositing a silicon oxide layer and a silicon nitride layer which are used as protection layers of an IC region; 2, making an MEMS structure through adopting an MEMS surface sacrificial layer technology; 3, etching to remove the silicon nitride protection layer of the IC region, etching the silicon oxide protection layer to form a lead hole, depositing and imaging the metal to form the metal interconnection; and 4, removing the sacrificial layer of an MEMS region, and releasing the MEMS movable structure. The method needs no special low-stress silicon nitride production equipment, adopts above IC-MEMS intersection technology, and allows the internal stress of integrated chips to be controlled through selectively removing the silicon nitride protection layer, so the influence of the integration technology to the IC performances is reduced, and the technology is simple and reliable.

Description

technical field [0001] The invention belongs to the field of micro-electro-mechanical systems (MEMS) and integrated circuit IC (CMOS) processing technology, and relates to a monolithic integration method of MEMS and IC technology, and adopts a mixed technology method of MEMS-IC-MEMS to simultaneously form MEMS and IC on a single wafer. The CMOS part is especially used in the field of manufacturing MEMS chips containing CMOS circuits. Background technique [0002] There are many advantages of monolithic integration of MEMS and IC, including reducing parasitic capacitance, reducing chip size, reducing cost, reducing packaging pressure, and improving reliability. The usually selected integration scheme is made by MEMS process after IC, that is, post-CMOS process. The design of post-CMOS integration scheme focuses on how to control the influence of MEMS process on IC circuit. Since IC circuits are composed of single-transistor NMOS or PMOS, studies have shown that the performa...

AI Technical Summary

Problems solved by technology

At present, some of the integration solutions of well-known chip companies such as ADI use PECVD silicon nitride, and some use LPCVD low-stress silicon nitride. These solutions have high controllability for processing equipment and processes. requirements, the silicon nitride film that needs to be produced has both low stress and high corrosion selection ratio, and it is difficult for general equipment to make a silicon nitride film that meets the demand

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