Thermosetting nano-imprint resists: novel materials for adhesive wafer bonding

In this paper we present for the first time the use of the thermosetting nano-imprint resist series mr-I 9000 as adhesive wafer bonding material suitable for heterogeneous three-dimensional (3D) integration of MEMS with integrated circuits. Detailed adhesive bonding process parameters for the thermosetting nano-imprint resist are presented with which void-free and uniform bonding interfaces can be achieved. Experiments have been performed to optimize the thickness uniformity of the nano-imprint resist layer in the bonded wafer stack. The use of nano-imprint resists as adhesive material for wafer-to-wafer bonding are specifically suitable for applications in which the adhesive layer is used as a temporary or sacrificial bonding material.