Low temperature transition to a superconducting phase in boron-doped silicon films grown on (001)-oriented silicon wafers

TL;DR

This study investigates the emergence of superconductivity in boron-doped silicon films grown on silicon wafers, revealing a low-temperature transition to a superconducting phase at specific doping levels with detailed magnetic properties.

Contribution

It provides new insights into the doping-dependent superconducting transition in boron-doped silicon films grown by Gas Immersion Laser Doping.

Findings

Superconductivity appears above 2.5 at.% boron doping.

Critical temperature reaches 0.6K at 8 at.% doping.

Upper critical field is about 1000 G, characteristic of a type II superconductor.

Abstract

We report on a detailed analysis of the superconducting properties of boron-doped silicon films grown along the 001 direction by Gas Immersion Laser Doping. The doping concentration cB has been varied up to approx. 10 at.% by increasing the number of laser shots to 500. No superconductivity could be observed down to 40mK for doping level below 2.5 at.%. The critical temperature Tc then increased steeply to reach 0.6K for cB = 8 at%. No hysteresis was found for the transitions in magnetic field, which is characteristic of a type II superconductor. The corresponding upper critical field Hc2(0) was on the order of 1000 G, much smaller than the value previously reported by Bustarret et al. in Nature (London) 444, 465 (2006).