Pulsed laser deposition of high-quality NbN thin films

Abstract

Pulsed laser deposition has been used to grow superconducting NbN thin films from niobium targets in a reactive gas atmosphere of N2 (10% H2). The structural and electrical properties of the deposited films have been determined as a function of substrate temperature and crystallographic orientation. Highly textured NbN was deposited on MgO (100). Films deposited on MgO at 600 °C in 60 mTorr gas pressure were characterized by Tc=16.6 K, Jc (4.2 K)=7.1 MA/cm2, and λ(0)=3200 Å. Films grown on amorphous fused silica, under the same conditions, were polycrystalline and characterized by Tc=11.3 K and Jc (4.2 K)=1.8 MA/cm2.