Direct bonding of polycrystalline diamond substrate onto Si wafer under atmospheric conditions

A polycrystalline diamond substrate treated with a mixture of NH 3 and H 2 O 2 was directly bonded with a plasma-activated Si wafer. They formed atomic bonds by annealing at 250 °C after contacting surfaces in atmospheric air. The bonding method would contribute to the future large-scale integration of diamond heat spreaders with electronics.