# Exploiting OxRAM Resistive Switching for Dynamic Range Improvement of CMOS Image Sensors

## TL;DR

This paper introduces a novel use of OxRAM devices integrated into CMOS image sensors to enhance dynamic range by resistive signal compression, validated through experimental fabrication and characterization.

## Contribution

It proposes a modified 3T-APS circuit with OxRAM in 1T-1R configuration for dynamic range enhancement in CMOS image sensors.

## Key findings

- Achieved approximately 50 dB dynamic range improvement.
- Demonstrated effective resistive compression through OxRAM programming.
- Validated design with fabricated 4 Kb HfOx OxRAM matrix.

## Abstract

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.