Test-beam and simulation studies for the CLICTD technology demonstrator -- a monolithic CMOS pixel sensor with a small collection diode

TL;DR

This paper presents test-beam and simulation studies of the CLICTD monolithic CMOS pixel sensor, demonstrating its spatial and time resolution, efficiency, and innovative sub-pixel segmentation for improved performance.

Contribution

It introduces a novel monolithic CMOS pixel sensor with a small collection diode and sub-pixel segmentation, validated through experimental and simulation methods.

Findings

High spatial resolution achieved

Effective charge collection with segmented n-implant

Good timing performance and efficiency

Abstract

The CLIC Tracker Detector (CLICTD) is a monolithic pixel sensor featuring pixels of 30um x 37.5um and a small collection diode. The sensor is fabricated in a 180 nm CMOS imaging process, using two different pixel flavours: the first with a continuous n-type implant for full lateral depletion, and the second with a segmentation in the n-type implant for accelerated charge collection. Moreover, CLICTD features an innovative sub-pixel segmentation scheme that allows the digital footprint to be reduced while maintaining a small sub-pixel pitch. In this contribution, test-beam measurements for the pixel flavour with the segmented n-implant are presented. The performance is evaluated in terms of time and spatial resolution as well as efficiency. Furthermore, the test-beam data is compared to simulation studies using a combination of 3D TCAD and Monte Carlo simulation tools.