Development and characterization of a large area silicon pad array for an electromagnetic calorimeter

TL;DR

This paper details the development and testing of a large 6x6 silicon pad array for use in a high-energy physics electromagnetic calorimeter, demonstrating its performance in laboratory and beam tests.

Contribution

It introduces the first large-area silicon pad array designed for a forward calorimeter, meeting high-energy physics requirements and validated through experimental testing.

Findings

Successful fabrication of 36-pad silicon sensors

Effective performance in high-energy particle beam tests

Achievement of low leakage current and high breakdown voltage

Abstract

We present the research and development work of the first version of a 6*6 array of silicon pad detectors, carried out in India, for the proposed forward calorimeter (FOCAL) as part of the ALICE collaboration upgrade program at CERN. The primary motivation is to develop a large area silicon pad array realizing the challenging requirements of high-energy physics experiments such as low leakage current, high breakdown voltage and evaluate its performance as an active layer in the prototype silicon tungsten (Si-W) electromagnetic (EM) calorimeter. Towards these goals, a 36-pad silicon sensor with an individual pad size of 1 cm2 is designed on a 4-inch high resistivity N-type wafer and fabricated at Bharat Electronics Limited, Bangalore. The sensors have been used to assemble the prototype Si-W calorimeters and were successfully tested with high-energy particle beams. The design and development of the large area silicon sensor and its characterization using radioactive sources in the laboratory and high-energy particle beams are reported in this paper.