J. Phys. IV France 08 (1998) Pr9-239-Pr9-242
Direct wafer bonding : A new fabrication method for ferroelectric-silicon heterostructuresM. Alexe, R. Scholz, G. Kästner, A. Pignolet and U. Gösele
Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle/Saale, Germany
Ferroelectric-semiconductor heterostructures were fabricated using direct wafer bonding. Polycrystalline Bi4Ti3O12 ferroelectric thin films were deposited on 3" silicon wafers by chemical solution deposition. The films were polished and then directly bonded to silicon wafers in a micro-cleanroom. After thermal annealing in air at 500°C for 12 hours, the bonding energy increases up to 1.5 J/m2. High resolution transmission electron microscopy shows a significant difference between the bonded and reacted interfaces. A Metal-Ferroelectric-Silicon (MFS) structure containing the ferroelectric-Si bonded interface was achieved by polishing down and etching the handling wafer. Capacitance-voltage (C-V) and current-voltage (I-V) characteristics were measured for the Bi4Ti3O12/Si heterostructures with a bonded interface.
© EDP Sciences 1998