Semiconductor device and method of manufacturing semiconductor device

According to one embodiment, a method of manufacturing a semiconductor device includes: forming a laser peeling film above a first semiconductor substrate; forming, inside the laser peeling film, a thermal diffusion layer including a member has a coefficient of thermal conductivity higher than that of the laser peeling film is distributed in a plane parallel to a front surface of the first semiconductor substrate; forming a circuit layer including a semiconductor circuit above the laser peeling film; bonding the first and a second semiconductor substrates; applying a laser beam to a back surface of the first semiconductor substrate; and peeling the first semiconductor substrate to maintain the circuit layer on a side of the second semiconductor substrate.