Numerical modeling of a CMOS UV/blue photodetector based on MOSFET and lateral photosensitive diode

Summary A complementary metal‐oxide semiconductor photodetector with ring‐shaped structure is presented in this paper, which consists of a p‐channel metal‐oxide‐semiconductor field‐effect transistor and lateral photodiodes and can be applied for ultraviolet (UV)/blue detection. The p‐channel metal‐oxide‐semiconductor is enclosed by ring‐shaped lateral photodiodes and lateral ring‐shaped photodiodes for enlarging near‐surface depletion region of the photodetector. Photoelectric conversion process of the photodetector has been modeled, and some performance parameters of photodetector have been derived and evaluated. The simulation results show that the photodetector can exhibit a high current responsivity of 1 × 10 −3  Å even for ultra‐weak light such as 0.01 μW. The composite photodetector is fabricated in a standard 0.18 µm complementary metal‐oxide semiconductor technology. The test results reveal that the presented photodetector, which just like predicted by the model, is an effective way to solve the low response of silicon‐based UV detector. In a word, the presented photodetector has a big potential application value in weak light and UV/blue light detection. Copyright © 2015 John Wiley & Sons, Ltd.