Investigating the impact of the diode edge geometry on the effective active area of silicon sensors using AREA-X

TL;DR

This study uses AREA-X to analyze how diode edge geometry affects the active area of silicon sensors, revealing that edge design influences sensor performance beyond just the bias ring size.

Contribution

The paper introduces a detailed measurement approach with AREA-X to evaluate how different diode edge geometries impact the active area of silicon sensors.

Findings

Active area depends on edge structure configuration.

Wider edge regions can enhance sensor performance.

Edge design influences charge collection efficiency.

Abstract

Sensors for particle tracking detectors are required to provide a maximum active area in addition to fulfilling performance criteria concerning radiation hardness, charge collection and operating conditions (e.g. leakage current, depletion voltage and breakdown voltage). While the requirement for optimised coverage within the tracking detector necessitates a slim sensor edge between active region and physical sensor edge, wider edge regions were found to be beneficial for the sensor performance during an early prototyping phase. In order to study the impact of differently sized edge regions, test structures were used to compare their individual active regions. Measurements of each diode were performed using a micro-focused X-ray beam to map its respective active area. This paper presents measurements of these test structures using AREA-X showing that the active area of a silicon particle tracking sensor does not only depend on the size of its bias ring, but also the size and configuration of its edge structure.