Studies of Growth Instabilities and Roughening in Sputtered NbN Films Using a Multilayer Decoration Technique

Abstract
A number of recent theories predict scaling laws for the roughening of growing thin films. We present a powerful new experimental technique for studying the internal morphology of films exhibiting roughening, together with preliminary results first demonstrating some fundamental aspects of these models. Sputtered films of NbN are decorated periodically by AlN layers and examined by cross-section transmission electron microscopy to reveal scaling-law growth and parabolic-capped columns whose diameter and layer roughness (interface width) increase with time (i.e. film thickness).