# First demonstration of 200, 100, and 50 um pitch Resistive AC-Coupled Silicon Detectors (RSD) with 100% fill-factor for 4D particle tracking

## TL;DR

This paper reports the development and testing of resistive AC-coupled silicon detectors with ultra-fine pitches of 50, 100, and 200 micrometers, achieving high timing and 4D tracking capabilities.

## Contribution

It introduces a novel resistive AC-coupled silicon detector design with very fine pitches, maintaining high performance for 4D particle tracking.

## Key findings

- Successful fabrication of 50, 100, and 200 um pitch RSDs
- Maintained high timing resolution with fine pitches
- Demonstrated suitability for 4D particle tracking

## Abstract

We designed, produced, and tested RSD (Resistive AC-Coupled Silicon Detectors) devices, an evolution of the standard LGAD (Low-Gain Avalanche Diode) technology where a resistive n-type implant and a coupling dielectric layer have been implemented. The first feature works as a resistive sheet, freezing the multiplied charges, while the second one acts as a capacitive coupling for readout pads. We succeeded in the challenging goal of obtaining very fine pitch (50, 100, and 200 um) while maintaining the signal waveforms suitable for high timing and 4D-tracking performances, as in the standard LGAD-based devices.