Glancing angle deposition is a physical vapour deposition process used in the fabrication of structured thin films.  During deposition, the film porosity and growth direction is controlled by substrate motion.  At low deposition angles, obliquely deposited films are continuous solid films with structured pores.  At sufficiently large deposition angles and low substrate temperatures the film porosity increases to the point where the film becomes a randomly distributed array of isolated columnar structures.  Both types of films have been shown to be of interest in a variety of applications[1].  Incorporation of ion bombardment during film deposition provides additional control over film morphology enabling a new regime of columnar architectures and porosities, which have been shown to be useful in humidity sensing applications[2].  Here we investigate modification to the column growth angle and film density in titanium dioxide and silicon dioxide films and how these affect the optical properties measured by variable angle spectroscopic ellipsometry.  In addition, the use of advanced substrate motion algorithms in conjunction with ion assisted deposition to provide additional control over film morphology will be addressed.  Preliminary results on modification of the film surface area, measured with the Brunauer, Emmett, Teller method, will also be presented.

[1] M. M. Hawkeye, M. J. Brett, Glancing angle deposition: Fabrication, properties, and applications of micro- and nanostructured thin films, J. Vac. Sci. Technol. A 25 (2007) 1317-1335.

[2] M.T. Taschuk, J.B. Sorge, J.J. Steele, M.J. Brett, Ion-Beam Assisted Glancing Angle Deposition for Relative Humidity Sensors, IEEE Sens. J. 8 (2008) 1521-1522.