Negative substrate bias induced modifications of the physical properties of DC sputter deposited nano-crystalline Mo thin films

TL;DR

This study investigates how applying a negative substrate bias during DC sputtering influences the physical properties of nano-crystalline molybdenum thin films, aiming to optimize them for solar and cryogenic detector applications.

Contribution

It demonstrates that negative substrate bias can significantly improve surface roughness and electrical resistivity of Mo thin films without notably affecting superconducting transition temperature.

Findings

Surface roughness was reduced.

Electrical resistivity was improved.

Superconducting transition temperature remained unchanged.

Abstract

Negative bias on substrate during DC sputter deposition of nano-crystalline molybdenum thin films has been utilized to tune their properties for solar cells and the cryogenic radiation detector applications. Films have been deposited on Si substrates under different out of plane negative biases aiming to improve their physical properties such as the sheet resistance, superconducting transition temperature, width of transition and surface roughness. Significant modifications in the electrical and surface morphological properties of nano-crystalline Mo thin films have been reported. The superconducting transition temperature and crystallite size of the films does not show much improvement but the surface roughness and electrical resistivity of the film have been improved by the application of substrate bias.