Transfer of patterned ion-cut silicon layers

The technique of transferring patterned ion-cut layers from one Si wafer to another was demonstrated. The starting silicon wafer was masked with checkerboard and line patterns with a 3 μm thick polymethylmethacrylate/photoresist and was implanted with 5×1016 H+ ions/cm2 at 150 keV. After stripping off the mask, the wafer was bonded to an oxide-coated receptor wafer through low-temperature direct wafer bonding. Heat treatment of this bonded pair showed that the hydrogen-induced silicon surface layer cleavage (ion cut) could propagate throughout about 16 μm×16 μm of nonimplanted material with implanted regions only 4 μm wide. Mask width, spacing, and implantation profiles through the mask shape were shown to have effects on the internal microfracturing mechanisms.