A NEW BONDING TECHNIQUE FOR MICROWAVE DEVICES

Over the past five years, a great deal of work has been done to perfor m semiconductor die attach with AuSn alloys, Successful die attach has recently been achieved using Au and Sn multilayers evaporated onto th e die or the host substrate, However bonding techniques with thin (bel ow 5 mu m) AuSn layers for very thin semiconductor devices have not ye t been reported, The increasing demand for more advanced optoelectroni c integrated circuits has created the need to bond materials having di fferent lattice constants (e.g., GaAs on Si), In this paper we report a new way for the bonding of epitaxial lift-off (ELO) devices onto hos t substrates, Three of the multilayer structures investigated in this work produce a AuSn alloy bond with approximately 84 wt % gold, but ca n be bonded with a peak temperature below 280 degrees C, The bonded sa mples were investigated with several standard surface analysis techniq ues: Optical microscopy, scanning electron microscopy (SEM), and energ y dispersive X-ray analysis (EDX). We conclude that much thinner bondi ng layers can be attained than thus far reported, The results of ow re search allow us to optimize the layer structure and bonding parameters .