Test of a fine pitch SOI pixel detector with laser beam

TL;DR

This paper evaluates a 19x19 um SOI pixel detector using laser pulses to simulate particle tracks, measuring charge collection and depletion characteristics to assess its potential for particle detection applications.

Contribution

It presents the first measurement of signal amplitude versus bias voltage for a fine pitch SOI pixel detector, demonstrating its charge collection efficiency with laser simulation.

Findings

Most charge collected inside seed pixel

Signal amplitude varies with bias voltage

Laser pulses effectively simulate particle tracks

Abstract

A silicon pixel detector with fine pitch size of 19x19 um, developed base on SOI (silicon on insulator) technology, was tested under the illumination of infrared laser pulses. As an alternative way to particle beam tests, the laser pulses were tuned to very short duration and small transverse profile to simulate the tracks of MIPs (minimum ionization particles) in silicon. Hit cluster sizes were measured with focused laser pulses propagating through the SOI detector perpendicular to its surface and most of the induced charge was found to be collected inside the seed pixel. For the first time, the signal amplitude as a function of the applied bias voltage was measured for this SOI detector, deepening understanding of its depletion characteristics.