A low-temperature bonding method based on au/in isothermal solidification

Abstract

The invention discloses a low-temperature bonding method based on Au / In isothermal solidification, comprising: forming a first gold pattern layer on a bonding surface of a first substrate; forming a bump pattern on a bonding surface of a second substrate layer; on the bonding surface of the second substrate, the second gold pattern layer and the indium pattern layer covering the bump pattern layer are sequentially formed; the bonding surface of the first substrate is bonded to the second substrate Align and secure the bonding surfaces for bonding. The present invention uses a raised dot pattern layer on the bottom layer of the metal film. The raised dot pattern layer not only reduces the bonding alignment accuracy, but also enhances the contact force in the bonding process, which can greatly improve the bonding quality.

Description

technical field [0001] The invention relates to a low-temperature bonding method based on Au / In isothermal solidification. Background technique [0002] Bonding technology refers to the technology in which two silicon wafers are attracted to each other by the van der Waals force at room temperature, and the surface groups of the silicon wafers undergo chemical interactions to bond together, which can combine surface silicon processing and bulk silicon processing. Organically combined is an important processing method in MEMS (micro-electromechanical systems) technology. The use of bonding technology can reduce the complexity of single silicon wafer processing, so as to realize complex communication, cavity and SOI (silicon on insulator) material preparation, etc. In addition, bonding technology can also realize the permanent connection of components of different materials in MEMS devices, so as to realize three-dimensional integration and wafer-level packaging of chips. ...

AI Technical Summary

Problems solved by technology

[0009] 1. Susceptible to the limitations of the materials to be bonded

For example, anodic bonding requires the migration of sodium ions during the bonding process, which can only be used for silicon-glass bonding, and surface-activated low-temperature bonding, usually only for direct bonding between silicon-silicon

[0010] 2. The temperature during low temperature bonding, that is, the temperature range that the bonding interface can withstand is small

[0011] 3. It is easy to be limited by the flatness of the surface to be bonded

For example, anode bonding, Au / Si eutectic bonding, silicon-silicon bonding, etc., the flatness of the bonding surface is usually required to be less than 1 μm, which greatly increases the difficulty and cost of the process

[0012] 4. Not easy to graph

For example, surface-activated low-temperature bonding is difficult to meet the requirements of patterned circuits and wafer bonding

[0013] 5. Higher requirements for bonding alignment accuracy

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