Reliability Characterization Of Au-In Transient Liquid Phase Bonding Through Electrical Resistivity Measurement

Transient liquid phase (TLP) die-attach bonding is an attractive technique for high-temperature semiconductor device packaging. In this paper, the material reliability of gold-indium (Au-In) TLP bonding is investigated utilizing electrical resistivity measurement as an indicator of material diffusion. Samples were fabricated featuring a TLP reaction, representative of TLP die-attach, by depositing TLP materials on glass substrates with various Au-In compositions, but with identical barrier layers, and were then used for reliability investigation. The samples were annealed at 200 °C and then stressed with thermal cycling. Samples containing high indium content in the TLP bond are shown to have poor reliability due to material diffusion through barrier layers, whereas the samples containing sufficient gold content proved reliable through electrical resistivity measurement, energy-dispersive X-ray spectroscopy, focused ion beam, and scanning electron microscope characterization