Test of CZT Detectors with Different Pixel Pitches and Thicknesses

TL;DR

This paper reports on the optimization of photolithographic contact processes for CZT detectors with varying pixel pitches and thicknesses, demonstrating high yield and performance improvements for different detector configurations.

Contribution

It introduces an optimized photolithographic process enabling high-yield pixel contacts down to 50 microns and evaluates detector performance with different thicknesses and pixel readouts.

Findings

High yield of good pixels at 50 micron pitch

Effective performance of 0.5 cm and 0.75 cm thick detectors

Successful contact process optimization

Abstract

The Modified Horizontal Bridgman (MHB) process produces Cadmium Zinc Telluride (CZT) crystals with high yield and excellent homogeneity. Various groups,including our own, previously reported on the test of 2x2x0.5 cm3 MHB CZT detectors grown by the company Orbotech and read out with 8x8 pixels. In this contribution, we describe the optimization of the photolithographic process used for contacting the CZT detector with pixel contacts. The optimized process gives a high yield of good pixels down to pixel diameters/pitches of 50 microns. Furthermore, we discuss the performance of 0.5 cm and 0.75 cm thick detectors contacted with 64 and 225 pixel read out with the RENA-3 ASICs from the company NOVA R&D.