Molybdenum low resistance thin film resistors for cryogenic devices

TL;DR

This paper investigates the fabrication of low-resistance molybdenum thin-film resistors for cryogenic NbN electronic devices, emphasizing interface quality improvements through ion cleaning and layered contact pads.

Contribution

It introduces a novel ion cleaning-activation process and layered contact pads to achieve ultra-low contact resistance in molybdenum resistors for cryogenic applications.

Findings

Contact resistance below 1 Ohm achieved

High-quality Mo/NbN interfaces confirmed by microscopy

Effective ion cleaning process developed

Abstract

We present a study of thin-film molybdenum resistors for NbN electronics operating at cryogenic temperatures. The key step is the 0.5-1.5 keV ion cleaning-activation of NbN before Mo deposition which allows to obtain a high-quality Mo/NbN interface which together with additional aluminum bandage layer in the area of contact pads allow to reduce contact resistance below 1 Ohm. The quality of the interfaces is confirmed by transmission electron microscopy and X-ray reflectometry.