Total Ionizing Dose Effects on CMOS Image Sensor for the ULTRASAT Space Mission

TL;DR

This paper investigates the effects of Total Ionizing Dose radiation on CMOS image sensors intended for the ULTRASAT space telescope, providing initial experimental insights into sensor degradation due to radiation exposure.

Contribution

It presents the first TID measurements on test sensors for ULTRASAT, highlighting their radiation tolerance and degradation characteristics before final sensor deployment.

Findings

Preliminary TID measurement results obtained from gamma irradiation.

Insights into sensor degradation mechanisms under radiation.

Assessment of sensor suitability for space radiation environment.

Abstract

ULTRASAT (ULtraviolet TRansient Astronomy SATellite) is a wide-angle space telescope that will perform deep time-resolved surveys in the near-ultraviolet spectrum. ULTRASAT is a space mission led by the Weizmann Institute of Science and the Israel Space Agency and is planned for launch in 2025. The camera implements backside-illuminated, stitched pixel sensors. The pixel has a dual-conversion-gain 4T architecture, with a pitch of $9.5$ $\mu m$ and is produced in a $180$ $nm$ process by Tower Semiconductor. Before the final sensor was available for testing, test sensors provided by Tower were used to gain first insights into the pixel's radiation tolerance. One of the main contributions to sensor degradation due to radiation for the ULTRASAT mission is Total Ionizing Dose (TID). TID measurements on the test sensors have been performed with a Co-60 gamma source at Helmholz Zentrum Berlin and CC-60 facility at CERN and preliminary results are presented.