A microfabricated device and method for forming a microfabricated device are described. A thin membrane including silicon (680) is formed on a silicon body (25) by bonding a silicon-on-insulator substrate (685) to a silicon substrate. The handle and insulator layers (695, 690) of the silicon-on-insulator substrate are removed, leaving a thin membrane of silicon bonded to a silicon body such that no intervening layer of insulator material remains between the membrane and the body. A piezoelectric layer is bonded to the membrane.
