A CMOS Image Sensor with 200-1000 nm Spectral Response and High Robustness to Ultraviolet Light Exposure

Abstract

In this paper, a 5.6 μm pixel pitch CMOS image sensor with a wide spectral response and high robustness to ultraviolet light (UV-light) exposure is reported. In the in-pixel buried pinned photodiode, a surface thin p^+ layer with a steep dopant profile is uniformly formed on the flattened Si surface to improve the UV-light sensitivity and the stability of the light sensitivity to a strong UV-light exposure. The fabricated chip exhibited a spectral response to the wide light waveband of 200-1000 nm, and the sensitivity degradation did not occur after the strong UV-light exposure stress.