Title :
Gold-tin bonding for 200mm wafer level hermetic MEMS packaging
Author :
Garnier, A. ; Lagoutte, E. ; Baillin, X. ; Gillot, C. ; Sillon, N.
Author_Institution :
CEA-LETI, MINATEC, Grenoble, France
Abstract :
Gold-Tin eutectic bonding was studied to get hermetic packaging at wafer level. Scanning Electron Microscopy cross section images showed the sealing joint morphology at different stages including before bonding and after bonding with or without thermal treatment at 400°C. Electron Dispersive X-ray Spectrometry enabled to get chemical information of observed phases. The Ni layer which was used as diffusion barrier reacts with the solder to form a nearly void free joint. Shear strength was in the range of 70 MPa before and after thermal treatment at 400°C. Hermeticity was assessed by measurement of membrane deflection caused by He overpressure. The air standard leak rate was lower than 2.6×10-11 atm.cm3/s. After Through Silicon Via (TSV) process, low contact resistances in the range of 10 mΩ were obtained for the joint as for the TSV.
Keywords :
X-ray chemical analysis; gold alloys; integrated circuit bonding; microfabrication; micromechanical devices; nickel alloys; scanning electron microscopy; shear strength; solders; three-dimensional integrated circuits; tin alloys; wafer level packaging; Au-Sn; Ni; TSV process; air standard leak rate; diffusion barrier; electron dispersive x-ray spectrometry; gold-tin eutectic bonding; low contact resistances; membrane deflection; resistance 10 mohm; scanning electron microscopy cross section images; sealing joint morphology; shear strength; size 200 mm; temperature 400 degC; thermal treatment; through silicon via process; void free joint solder; wafer level hermetic MEMS packaging; Bonding; Gold; Joints; Nickel; Packaging; Through-silicon vias; Tin;
Conference_Titel :
Electronic Components and Technology Conference (ECTC), 2011 IEEE 61st
Conference_Location :
Lake Buena Vista, FL
Print_ISBN :
978-1-61284-497-8
Electronic_ISBN :
0569-5503
DOI :
10.1109/ECTC.2011.5898726
