Title :
Low-temperature gold-gold bonding using selective formation of nanoporous powders for bump interconnects
Author :
Mimatsu, Hayata ; Mizuno, Jun ; Kasahara, T. ; Saito, Masato ; Shoji, Shuji ; Nishikawa, Hisashi
Author_Institution :
Major in Nano-Sci. & Nano-Eng, Waseda Univ., Tokyo, Japan
Abstract :
We proposed low-temperature Au-Au bump interconnects bonding using nanoporous Au-Ag powders as a connective adhesion. The nanoporous powders were formed by de-alloying Au-Ag alloy in HNO3 solution. To optimize the pore size, the influence of the annealing temperature on the porous structures was investigated. Selective transfer of the nanoporous powders on bumps was obtained by stamping process. Bonding strength of about 2.4 MPa was achieved at 150 °C by using nanoporous Au-Ag powders. Bonding interface was evaluated by scanning acoustic microscope and scanning electron microscopy. This result indicated that the nanoporous powder is a useful material for low-temperature Au-Au bonding.
Keywords :
acoustic microscopes; adhesive bonding; gold alloys; hydrogen compounds; integrated circuit interconnections; nanoparticles; nitrogen compounds; scanning electron microscopy; silver alloys; Au-Ag; Au-Au; HNO3; annealing temperature; bonding interface; bonding strength; connective adhesion; dealloying; low-temperature Au-Au bump interconnects bonding; nanoporous Au-Ag powders; pore size; porous structures; scanning acoustic microscope; scanning electron microscopy; selective transfer; stamping process; temperature 150 C; Bonding; Gold; Powders; Silicon; Substrates; Surface treatment;
Conference_Titel :
Micro Electro Mechanical Systems (MEMS), 2014 IEEE 27th International Conference on
Conference_Location :
San Francisco, CA
DOI :
10.1109/MEMSYS.2014.6765845
