  We present a unique application of OxRAM devices in CMOS Image Sensors (CIS)
for dynamic range (DR) improvement. We propose a modified 3T-APS (Active Pixel
Sensor) circuit that incorporates OxRAM in 1T-1R configuration. DR improvement
is achieved by resistive compression of the pixel output signal through
autonomous programming of OxRAM device resistance during exposure. We show that
by carefully preconditioning the OxRAM resistance, pixel DR can be enhanced.
Detailed impact of OxRAM SET-to-RESET and RESET-to-SET transitions on pixel DR
is discussed. For experimental validation with specific OxRAM preprogrammed
states, a 4 Kb 10 nm thick HfOx (1T-1R) matrix was fabricated and
characterized. Best case, relative pixel DR improvement of ~ 50 dB was obtained
for our design.
