A method of manufacturing a semiconductor device includes forming isolation regions, a gate insulator film and gate electrodes, implanting in the silicon substrate with impurity ions, annealing to recover crystallinity of the implanted silicon substrate without diffusing the impurity ions, depositing an interlayer insulator film on the isolation regions, the silicon substrate, and the gate electrodes, and heating the silicon substrate by irradiating a light having a wavelength that the light is absorbed by the silicon substrate without being absorbed by the interlayer insulator film, activating the impurity ions so as to form source and drain regions.