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Recent progress on bumpless Cu/SiO2 hybrid bonding for 3D heterogeneous integration.

Authors :
Li, Ge
Kang, Qiushi
Niu, Fanfan
Wang, Chenxi
Source :
Microelectronics International. 2023, Vol. 40 Issue 2, p115-131. 17p.
Publication Year :
2023

Abstract

Purpose: Bumpless Cu/SiO2 hybrid bonding, which this paper aims to, is a key technology of three-dimensional (3D) high-density integration to promote the integrated circuits industry's continuous development, which achieves the stacks of chips vertically connected via through-silicon via. Surface-activated bonding (SAB) and thermal-compression bonding (TCB) are used, but both have some shortcomings. The SAB method is overdemanding in the bonding environment, and the TCB method requires a high temperature to remove copper oxide from surfaces, which increases the thermal budget and grossly damages the fine-pitch device. Design/methodology/approach: In this review, methods to prevent and remove copper oxidation in the whole bonding process for a lower bonding temperature, such as wet treatment, plasma surface activation, nanotwinned copper and the metal passivation layer, are investigated. Findings: The cooperative bonding method combining wet treatment and plasma activation shows outstanding technological superiority without the high cost and additional necessity of copper passivation in manufacture. Cu/SiO2 hybrid bonding has great potential to effectively enhance the integration density in future 3D packaging for artificial intelligence, the internet of things and other high-density chips. Originality/value: To achieve heterogeneous bonding at a lower temperature, the SAB method, chemical treatment and the plasma-assisted bonding method (based on TCB) are used, and surface-enhanced measurements such as nanotwinned copper and the metal passivation layer are also applied to prevent surface copper oxide. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
13565362
Volume :
40
Issue :
2
Database :
Academic Search Index
Journal :
Microelectronics International
Publication Type :
Academic Journal
Accession number :
162467333
Full Text :
https://doi.org/10.1108/MI-07-2022-0121