A dual-capture wide dynamic range CMOS image sensor using an in-pixel floating-diffusion (FD) storage capacitor is proposed. The proposed structure uses the FD as a storage capacitor. The potential of the FD node is read out using a floating-gate capacitor without a contact metallization of the FD node to reduce the leakage. The proposed sensor was fabricated using a 0.35-μm CMOS process. The chip includes 320 × 240 pixels whose pitch is 5.6 μm and whose fill factor is 36%. The measurement results show 100-dB dynamic range, and the leakage at the non-metalized FD is reduced to about one-third of that of the conventional FD with the contact metallization.
Bibliographical noteFunding Information:
Manuscript received January 29, 2008; revised May 27, 2008. Current version published September 24, 2008. This work was supported by Sam-sung Electronics Company, Ltd. The review of this paper was arranged by Editor J. Tower.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering