Performance of a TiN-coated monolithic silicon pin-diode array under mechanical stress

TL;DR

This study evaluates the mechanical stress effects on a TiN-coated silicon pin-diode array used in neutrino detection, finding that pogo pin contacts do not impair electrical performance under stress.

Contribution

It demonstrates that pogo pin contacts to TiN-coated silicon diodes maintain electrical integrity under mechanical stress, relevant for high-precision detectors.

Findings

Pogo pins establish good electrical contact with TiN.

No impact on detector resolution due to mechanical stress.

Reverse-bias leakage current remains unaffected.

Abstract

The Karlsruhe Tritium Neutrino Experiment (KATRIN) will detect tritium beta- decay electrons that pass through its electromagnetic spectrometer with a highly- segmented monolithic silicon pin-diode focal-plane detector (FPD). This pin-diode array will be on a single piece of 500-{\mu}m-thick silicon, with contact between titanium nitride (TiN) coated detector pixels and front-end electronics made by spring-loaded pogo pins. The pogo pins will exert a total force of up to 50N on the detector, deforming it and resulting in mechanical stress up to 50 MPa in the silicon bulk. We have evaluated a prototype pin-diode array with a pogo-pin connection scheme similar to the KATRIN FPD. We find that pogo pins make good electrical contact to TiN and observe no effects on detector resolution or reverse-bias leakage current which can be attributed to mechanical stress.