A time correlation (TC) image sensor is a device that produces 3-phase time-correlated signals between the incident light intensity and three reference signals. A conventional implementation of the TC image sensor using a standard CMOS technology works at low frequency and with low sensitivity. In order to achieve higher modulation frequency and high sensitivity, the TC image sensor with a dual potential structure using a pinned diode is proposed. The dual potential structure is created by changing the impurity doping concentration in the two different potential regions. In this structure, high-frequency modulation can be achieved, while maintaining a sufficient light receiving area. A prototype TC image sensor with 366×390pixels is implemented with 0.18-μm 1P4M CMOS image sensor technology. Each pixel with the size of 12μm×12μm has one pinned photodiode with the dual potential structure, 12 transistors and 3capacitors to implement three-parallel-output active pixel circuits. A fundamental operation of the implemented TC sensor is demonstrated.

Date Published: 25 January 2010
PDF: 7 pages
Proc. SPIE 7536, Sensors, Cameras, and Systems for Industrial/Scientific Applications XI, 75360S (25 January 2010); doi: 10.1117/12.846532

Published in SPIE Proceedings Vol. 7536:
Sensors, Cameras, and Systems for Industrial/Scientific Applications XI
Erik Bodegom; Valérie Nguyen, Editor(s)