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Title: Interfacial characterization of Al-Al thermocompression bonds

Interfaces formed by Al-Al thermocompression bonding were studied by the transmission electron microscopy. Si wafer pairs having patterned bonding frames were bonded using Al films deposited on Si or SiO{sub 2} as intermediate bonding media. A bond force of 36 or 60 kN at bonding temperatures ranging from 400–550 °C was applied for a duration of 60 min. Differences in the bonded interfaces of 200 μm wide sealing frames were investigated. It was observed that the interface had voids for bonding with 36 kN at 400 °C for Al deposited both on Si and on SiO{sub 2}. However, the dicing yield was 33% for Al on Si and 98% for Al on SiO{sub 2}, attesting for the higher quality of the latter bonds. Both a bond force of 60 kN applied at 400 °C and a bond force of 36 kN applied at 550 °C resulted in completely bonded frames with dicing yields of, respectively, 100% and 96%. A high density of long dislocations in the Al grains was observed for the 60 kN case, while the higher temperature resulted in grain boundary rotation away from the original Al-Al interface towards more stable configurations. Possible bonding mechanisms and reasons for the large difference in bonding quality of the Al films depositedmore » on Si or SiO{sub 2} are discussed.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [1]
  1. Centre for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1032, Blindern, N-0315 Oslo (Norway)
  2. (Norway)
  3. SINTEF Materials and Chemistry, Department of Materials and Nanotechnology, P.O. Box 124 Blindern, N-0314 Oslo (Norway)
  4. SINTEF ICT, Department of Microsystems and Nanotechnology, P.O. Box 124 Blindern, N-0314 Oslo (Norway)
Publication Date:
OSTI Identifier:
22596730
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 119; Journal Issue: 20; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM; BONDING; DENSITY; DEPOSITS; DISLOCATIONS; ELECTRONS; FILMS; GRAIN BOUNDARIES; INTERFACES; ROTATION; SILICA; SILICON OXIDES; TEMPERATURE RANGE 0400-1000 K; TRANSMISSION ELECTRON MICROSCOPY; YIELDS