Characterization of irradiated RD53A pixel modules with passive CMOS sensors

TL;DR

This study explores the use of CMOS foundries for fabricating silicon pixel sensors, characterizing irradiated and non-irradiated modules for performance metrics like charge collection and efficiency, demonstrating feasibility for high-radiation environments.

Contribution

First characterization of irradiated CMOS passive sensor modules interconnected with RD53A chips, demonstrating their potential for high-radiation particle detection applications.

Findings

Sensors maintained performance after irradiation up to 1.0×10^{16} n_eq/cm^2

Charge collection and efficiency were validated through laboratory and beam tests

Passive CMOS sensors show promise for integration in high-radiation environments

Abstract

We are investigating the feasibility of using CMOS foundries to fabricate silicon detectors, both for pixels and for large-area strip sensors. The availability of multi-layer routing will provide the freedom to optimize the sensor geometry and the performance, with biasing structures in poly-silicon layers and MIM-capacitors allowing for AC coupling. A prototyping production of strip test-structures and RD53A compatible pixel sensors was recently completed at LFoundry in a 150$\,$nm CMOS process. This paper will focus on the characterization of irradiated and non-irradiated pixel modules, composed by a CMOS passive sensor interconnected to a RD53A chip. The sensors are designed with a pixel cell of $25\times100\,\mu \mathrm{m}^2$ in case of DC coupled devices and $50\times50\,\mu \mathrm{m}^2$ for the AC coupled ones. Their performance in terms of charge collection, position resolution, and hit efficiency was studied with measurements performed in the laboratory and with beam tests. The RD53A modules with LFoundry silicon sensors were irradiated to fluences up to $1.0\times10^{16}\,\frac{\mathrm{n}_\mathrm{eq}}{\mathrm{cm}^2}$.