Atomic force microscopy studies of SnO2 thin film microstructures deposited by atomic layer epitaxy

ALE-grown, rutile-type SnO2 thin films and pas sensor structures based ther eupon were studied by AFM with main emphasis on cross-sectional investigati ons (X-AFM). On glass substrates the polycrystalline films showed a preferr ed orientation which depended on the film thickness and growth temperature while on single crystal sapphire (1 (1) over bar 02) the growth was heteroe pitaxial. For the X-AFM studies various sample preparation techniques were investigated but only ion beam etching gave satisfactory results and reveal ed substructures in the sensor structure consisting of Pt and SnO2 layers o n a silicon substrate.