MOS capacitors composed of the WOx high-
kgate dielectric were fabricated and investigated for the electrical properties under different light exposure conditions, i.e., blue, green, and red lights, separately. The sputter deposited WOx film layer was fully oxidized after the post deposition annealing step. The leakage current was increased by light exposure due to the generation and transport of electron-hole pairs. The shorter the exposure light wavelength is, the film shows less C-Vhysteresis, which is due to the more pronounced above mechanism.