Low temperature adhesive wafer bonding using OSTE(+) for heterogeneous 3D MEMS integration

We demonstrate, for the first time, the use of off stoichiometry thiolene-epoxy, OSTE(+) for adhesive wafer bonding. The dual cure system, with an initial UV-curing step followed by a second thermal cure, allows for high bond strength and potentially high quality material interfaces. We show that cured OSTE(+) is easily removed in oxygen plasma and that the characteristics of OSTE(+) make it a potential candidate for use in heterogeneous 3D MEMS integration. Furthermore, we show how the bond energies of wafers bonded with OSTE(+) adhesive compares with the bond energies of wafers bonded with Cyclotene 3022-46 (BCB) and mr-I 9150XP nanoimprint resist.