This talk starts with a brief introduction to the fundamentals of Atomic Force Microscopy (AFM) and some of the AFM techniques, including TappingMode AFM, where the AFM tip taps (rather than dragging on) the surface of the sample. Then, example images and data on thin films and coatings will show how AFM enables 1) visualizing qualitatively-meaningful-things such as surface texture, uniformity of substrate coverage, and grain structure; 2) quantifying the surface locally, through simultaneous measurements in all 3 dimensions on individual features anywhere on an image; and 3) globally quantifying the surface, through a host of statistical numerical representations for properties such as surface roughness, waviness, and average grain size--on the whole image or on any part of an image.

Some of the more recent techniques are discussed next, including nano-indenting/nano-scratching, and phase imaging. Nano-indenting/nano-scratching are used to test mechanical properties of thin films and coatings, e.g., hardness, wear, and adhesion. For example, variations in thin film deposition parameters can affect film adhesion: one film adheres better to the substrate, while another film does not adhere so well to the substrate, but adheres to itself well. The AFM can reveal these and other differences. The applications of phase imaging include detection of contamination on a surface, and identification of different phases or constituents of a polymer or polymer coating.

AFM's have traditionally been limited to scan areas of up to ~100 micrometers on a side, but that is changing. A new generation of instruments, the Atomic Force Profiler (AFP) is capable of profiling a surface in scans of up to 100mm long, and also imaging the surface in smaller areas to reveal both long-range and local topography with resolution that surpasses that of any stylus profilometer. The additional advantage of the AFP over all stylus profilometers is that it is far gentler on the sample, relying as it does on small intermitent contact forces of TappingMode for tracking the surface.

AFM data on thin films and coatings in early stages of production can be tied directly to performance of final products; examples of this in semiconductor and data storage industries are discussed, along with relevant automation features in some of today's AFM's.

In previous research work [1] the oxidation behaviour of W-(N) and W-Si-(N) sputtered coatings was characterised. The coatings containing Si were deposited from a tungsten target superimposed with 20 Si plates, presenting very high contents in this element (Si/W reaches 1). The coatings containing Si presented an amorphous structure in the as-deposited state. With thermal annealing the W-Si coating began to crystallise at 700ºC and finished for 950ºC. During this process, structural transformations took place either with phases change or with increase of the structural order. W-Si-N coating keeps its amorphous structure up to 1000ºC, presenting at this temperature the first signs of crystallisation. Veprek et al [2] found important improvements in the hardness values for W-Si-N films when small crystallites (<40nm) of W2N were dispersed in a Si-N amorphous matrix. The aim of this study is to evaluate the hardness and Young´s modulus of W-Si and W-Si-N films deposited by sputtering after have been thermal annealed at increasing temperatures. The results will be correlated with the degree of structural order obtained for the coatings.

[1] - C. Louro and A. Cavaleiro, accepted for publication in Thin Solid Films.

[2] - S. Veprek, M. Haussmann and S. Reiprich, J. Vac. Sci. Technol. A, 14(1996)46.

Zirconium oxide thin films were deposited by reactive circular d.c. magnetron sputtering on glass, silicon wafer and stainless steel substrates. The thickness of the films deposited varied between 200 nm and 3 µm. These coatings have many technological interesting properties, like good wear resistance, high insulating capability, chemical and thermal stability, high hardness and transparency.

The properties in interest were ratio Zr / O, nanohardness, surface roughness, film density, residual stress, refractive index and crystallographic structure. The properties were studied in terms of the process parameters such as sputtering gas pressure, target voltage and substrate bias voltage.

The highest deposition rate obtained for zirconium oxide thin film was 135 nm / min. The power of the target was 1500 W. The zirconium oxide thin films deposited had monoclinic structure having the density between 5.13 and 5.77 g cm^-3. The ratio Zr/O varied between 2.02 and 2.59 depending on the target voltage used. The related nanohardness and the surface roughness were between 12.1 and 17.8 GPa, and 2.9 and 12.6 nm, respectively. The intrinsic stress varied between - 1000 and 150 MPa. Arcing was observed during deposition resulting in defects and macroparticle contamination on the surface of the thin film.