A method for fabricating silicon-on-silicon substrates. A donor wafer (40) is attached to a target wafer (46) using a low-temperature bonding process. The low-temperature bonding process maintains the integrity of a layer of microbubbles (41). Subsequent processing separates a thin film (45) of material from the donor wafer. A high-temperature annealing process finishes the bonding process of the thin film to the target wafer to produce a hybrid wafer suitable for fabricating integrated circuit devices or other devices.