Design, fabrication and testing of Al/p-Si Schottky and pn junctions for radiation studies

TL;DR

This paper reports the design, fabrication, and initial testing of Al/p-Si Schottky and pn junctions on high-resistivity silicon for radiation studies, aiming to improve understanding of radiation effects on silicon detectors used in high-energy physics.

Contribution

It introduces new fabricated Schottky and pn diodes on p-type silicon wafers as test devices for radiation hardness studies in high-energy physics applications.

Findings

Devices tested before irradiation show expected electrical characteristics.

Fabrication process details are provided for reproducibility.

Future results on irradiated devices will further inform radiation effects.

Abstract

Strip and pixels sensors, fabricated on high resistivity silicon substrate, normally of p-type, are used in detectors for High Energy Physics (HEP) typically in a hybrid detector assembly. Furthermore, and owing to their inherent advantages over hybrid sensors, Monolithic Active Pixel Sensors (MAPS) fabricated in CMOS technology have been increasingly implemented in HEP experiments. In all cases, their use in higher radiation areas (HL-LHC and beyond) will require options to improve their radiation hardness and time resolution. These aspects demand a deep understanding of their radiation damage and reliable models to predict their behaviours at high fluences. As a first step, we fabricated several Schottky and n-on-p diodes, to allow a comparison of results and provide a backup solution for test devices, on 6 or 4-inch p-type silicon wafers with 50 {\mu}m epitaxial thickness and of doping concentration as they are normally used in HEP detectors and CMOS MAPS devices. In this paper, details of the design and fabrication process, along with test results of the fabricated devices before irradiation, will be provided. Additional test results on irradiated devices will be provided in subsequent publications.