Low-temperature direct wafer bonding and selective etching of yttrium iron garnet films on InP substrates

Summary form only given. Direct wafer bonding is an attractive technique for the heterogeneous integration of dissimilar materials, including III-V and silicon-on-insulator structures (SOI). Recently a novel technique (crystal ion slicing) has been reported by some of the authors for the epitaxial liftoff of magnetic garnet films for magnetooptic isolators. This technique makes use of fast etching in a sacrificial layer generated by the deep implantation of energetic (/spl sim/4 MeV) helium ions. The metal-oxide films detached by this process have been subsequently bonded onto semiconductor substrates with epoxy. In the paper we report on direct wafer bonding of ion-implanted bismuth-substituted yttrium iron garnets (Bi-YIG) films onto InP substrates at room temperature and selective etching of the implantation-induced sacrificial layer in the bonded material. The low bonding temperatures prevents "annealing out" of the implanted region.