Silicon-based eutectic bonding structure, micro-mechanical device, packaging structure and preparation method

Abstract

The invention discloses a silicon-based eutectic bonding structure, a micro-mechanical device, a packaging structure and a preparation method. The silicon-based eutectic bonding structure comprises a silicon boss wrapped in an insulating layer, wherein the surface height of the silicon boss is higher than or equal to the surface height of the insulating layer located at the bottom part of the silicon boss. A device unit in the micro-mechanical device is in bonding connection with a substrate unit through the silicon-based eutectic bonding structure, and an electrode of a substrate silicon wafer is led out to a device silicon wafer through the silicon-based eutectic bonding structure. The silicon boss structure is formed by using a silicon local oxidation method, a silicon region of the device is exposed, and etching penetration of a movable structure of the device is ensured. A cover plate packaging interconnection structure unit in the micro-mechanical packaging structure is mechanically and electrically connected by bonding a silicon-based eutectic bonding structure and a micro-mechanical device. According to the silicon-based eutectic bonding structure, the surface height of the silicon boss is higher than or equal to the surface height of the insulating layer by regulating and controlling the thickness of a silicon local oxide layer twice, and the mechanical connection reliability and the electrical contact reliability of the silicon-based eutectic bonding structure are improved.

Description

technical field [0001] The invention relates to a micromechanical device, a packaging structure and a preparation method, in particular to a silicon-based eutectic bonding structure, a micromechanical device, a packaging structure and a preparation method. Background technique [0002] Micro Electro Mechanical System (MEMS) is a general term for micromechanical components formed on silicon or other dielectric wafers through semiconductor technology and micro-nano processing technology, and finally integrated with signal processing circuits. Wafer bonding technology is a key technology for MEMS device manufacturing and packaging. The main wafer bonding technologies include silicon-silicon fusion bonding, silicon-glass anode bonding, glass paste bonding, polymer bonding, and eutectic bonding. , diffusion bonding, etc. Different bonding technologies have their limitations, but silicon-silicon bonding (bonding temperature is about 600-1200°C high, high wafer surface quality req...

AI Technical Summary

Problems solved by technology

In this case, if Au-Si, Al-Si and other silicon-based eutectic bonding technologies also need to build local electrical contacts (such as forming metal / semiconductor contacts) and local electrical contacts between the eutectic bonding metal and the silicon wafer body. The isolation region is used to form the electrical interconnection structure of the eutectic bonding layer, and a step introduced by the insulating layer will be generated between the bonding metal medium of the silicon-based eutectic reaction and the silicon body to form a certain height difference, while The existence of the height difference restricts the liquid phase flow channel formed by the metal / bulk silicon eutectic reaction to the edge of the step introduced by the insulating layer, which will hinder the reliable formation of the bonding structure based on the silicon-based eutectic reaction

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