Measurement of the relative response of TowerJazz Mini-MALTA CMOS prototypes at Diamond Light Source

TL;DR

This study measures how radiation damage affects the response of TowerJazz Mini-MALTA CMOS prototypes using high-resolution X-ray scanning at Diamond Light Source, comparing different pixel designs and irradiation types.

Contribution

It provides detailed measurements of radiation effects on Mini-MALTA CMOS prototypes with various pixel designs using micro-focus X-ray scans.

Findings

Radiation damage alters the in-pixel photon response.

Different pixel designs show varying radiation resilience.

Proton and neutron irradiation have distinct effects.

Abstract

This paper outlines the results of investigations into the effects of radiation damage in the mini-MALTA prototype. Measurements were carried out at Diamond Light Source using a micro-focus X-ray beam, which scanned across the surface of the device in 2 $\mathrm{\mu m}$ steps. This allowed the in-pixel photon response to be measured directly with high statistics. Three pixel design variations were considered: one with the standard continuous $\mathrm{n^-}$ layer layout and front-end, and extra deep p-well and $\mathrm{n^-}$ gap designs with a modified front-end. Five chips were measured: one unirradiated, one neutron irradiated, and three proton irradiated.