Fully Depleted Monolithic Active Microstrip Sensors: TCAD simulation study of an innovative design concept

Abstract

The paper presents the simulation studies of 10 $\mu$m pitch microstrips on a fully depleted monolithic active CMOS technology and describes their potential to provide a new and cost-effective solution for particle tracking and timing applications. The Fully Depleted Monolithic Active Microstrip Sensors (FD-MAMS) described in this work, which are developed within the framework of the ARCADIA project, are compliant with commercial CMOS fabrication processes. A TCAD simulation campaign was performed in the perspective of an upcoming engineering production run with the aim of designing FD-MAMS, studying their electrical characteristics and optimising the sensor layout for enhanced performance in terms of low capacitance, fast charge collection and low-power operation. A very fine pitch of 10 $\mu$m was chosen to provide very high spatial resolution. This small pitch still allows readout electronics to be monolithically integrated in the inter-strip regions, enabling the segmentation of long strips and the implementation of distributed readout architectures. The effects of surface radiation damage expected for total ionising doses of the order of 10 to 10$^5$ krad were also modelled in the simulations. The results of the simulations exhibit promising performance in terms of timing and low power consumption and motivate R&D efforts to further develop FD-MAMS; the results will be experimentally verified through measurements on the test structures that will be available at the beginning of 2021.