Properties of Ultra-Thin NbN Films for Membrane-Type THz HEB
Résumé
Various buffer layers have been investigated in order to improve the crystalline quality of NbN ultra-thin films. The structural properties, the thickness, the surface morphology of 5-10 nm NbN films have been studied by different techniques. Uncertainty on thickness measurements in this range and the relation between NbN film quality and gain bandwidth are discussed in the framework of their use in Hot Electron Bolometers (HEB).