A physical model of novel UV and blue-extended photodetector based on CMOS process

An improved type device serving as a photodiode for an ultraviolet and infrared (UV-IR) complementary photodetector is presented in this paper, which can be applied for ultraviolet (UV)/blue detection. The device has been modeled and some critical parameters of this new structure (such as spectral responsivity, breakdown voltage) have been derived and simulated. Simulation results by this model are shown that the UV photodiode area has to be 15 times-smaller than that of IR photodiode, which can effective offset parasitic current generated by the UV photodiode when the light irradiation for IR. A dark current of 3×10 ^-11 A at a voltage of 0V and the breakdown voltage of the UV-IR photodetector is about 14.1 volts. The photomutiplication gain rapidly increases with applied voltage when the photodetector is illuminated with μw 400nm light.