Progress on the radiation tolerance of CMOS Monolithic Active Pixel Sensors

Abstract

A: CMOS Monolithic Active Pixel Sensors (CPS) are ultra-light and highly granular silicon pixel detectors suited for highly sensitive charged particle tracking. Being manufactured with cost efficient standard CMOS processes, CPS may integrate sensing elements together with analogue and digital data processing circuits into one monolithic chip. This turns into 50 µm thin sensors, which provide an outstanding typical spatial resolution of few µm and a detection efficiency for minimum ionizing particles above 99.9%. The radiation tolerance of CPS was initially constrained by the limits of the CMOS processes used for their production but has been improved by orders of magnitudes during the last years.This work reviews the related R&D on the radiation tolerance of traditional CPS with partially depleted active medium as pioneered by the MIMOSA-series developed by the IPHC Strasbourg. Procedures for assessing radiation damage in those non-standard pixels are discussed and the major mechanisms of radiation damage are introduced. Techniques for radiation hardening are shown. Moreover, recent results on next generation CPS featuring fully depleted sensors based on improved CMOS processes are summarized.

Ion Microbeam Studies of Charge Transport in Semiconductor Radiation Detectors With Three-Dimensional Structures: An Example of LGAD

“…The increased demand for position-sensitive radiation sensing with enhanced radiation hardness and very good time resolution has paved the way for new solutions and new technologies of semiconductor detector manufacturing, often resulting in a complex 3D (three dimensional) structure of the final device [1,2]. Good examples of such detectors are monolithic silicon pixel detectors [3,4], multipixel silicon LGAD detectors [5][6][7][8], detectors with 3D electrodes (silicon and diamond) [9,10], etc. Studying the charge transport in such structures is most frequently accomplished today by different variations of the TCT (transient current technique) technique, which uses laser light to create charge carriers in certain detector regions, generally through the small openings in electrodes that enable passage of light [11,12].…”

Radiation-tolerant Silicon Detectors for the LHC Phase-II Upgrade and Beyond: Review of RD50 Activities

“…The drawback of CMOS sensors is their lower radiation tolerance compared to other sensor technologies; signal collection and efficiencies are significantly degraded at fluences on the order of 1×10 15 n eq /cm 2 [30]. Due to this, CMOS sensors are at the moment not considered for the most challenging radiation environments, i.e.…”

Study on the tolerance of partially and fully depleted CPS to non-ionizing radiation

“…The sensors showed neither an increase in noise nor significant non-ionizing bulk damage. These results were published in [Dev19] and presented in [LDB16].…”

“…Die Sensoren zeigen weder einen Anstieg des Rauschens noch nennenswerte durch nicht-ionisierende Strahlung entstandene Volumenschäden. Die Ergebnisse wurden zuerst in [LDB16] präsentiert und später in [Dev19] einer breiten Öffentlichkeit zugänglich gemacht.…”