Development of Low Temperature Bonding Method by Formic Acid Treatment using Pt Catalyst

2016 Fiscal Year Final Research Report

• Project/Area Number: 26289247
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Composite materials/Surface and interface engineering
• Research Institution: The University of Tokyo
• Principal Investigator: Suga Tadatomo 東京大学, 工学(系)研究科(研究院), 教授 (40175401)
• Co-Investigator(Renkei-kenkyūsha): FUJINO Masahisa 東京大学, 工学系研究科, 助教 (70532274) ; AKAIKW Masatake 東京大学, 工学系研究科, 研究員 (50150959)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: ギ酸 / 低温接合 / 接合界面 / 直接接合 / 還元 / 活性化接合 / 銅ー銅接合 / 実装

Outline of Final Research Achievements

A new low temperature bonding process using formic acid pretreatment with Pt catalyst was proposed. The bonding mechanism was clarified and the process was applied to integration of various devices, demonstrating its efficiency. The low temperature bonding is based on activation of the bonded surfaces, the oxide layers of which are reduced in two step reactions by hydrogen radicals generated by Pt catalyst from the formic acid. The process parameters were optimized systematically, and the results were applied successfully to Cu-Cu low temperature bonding below 200 degree C, SnAg-Cu direct bonding, TSV stacking, Cu-resin hybrid bonding, and polymer films with nano-adhesion layer. It indicates that the proposed method can provide a new tool for integrating semiconductor devices, MEMS, and power devices as well as bonding of high temperature superconductors wires.

Free Research Field

接合工学、実装工学