Europhysics Letters, 19 (1) pp. 27-32 (1992)

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

D. J. Miller, K. E. Gray, R. T. Kampwirth and J. M. Murduck

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 <it>internal</it> 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 an parabolic-capped columns whose 
diameter and layer roughness (interface width) inrease with time (i.e. 
film thickness).