Diffusion at interfcaes
We often grow our oxide thin films at rather high temperatures, often above 1000°C. This is useful for achieving step-flow growth and good surface morphologies, but it also presents a problem for heterointerfaces because diffusion across an interface may become a problem.
We have three techniques to study diffusion in thin films:
|FFM, Friction Force Microscopy||FFM can detect chemical changes on the surface, and is particularly useful if we have some form of chemical segregation on the surface.|
|CAICISS, CoAxial Impact Collision Ion Scattering Spectroscopy||Ion scattering is a surface-sensitive tool which can identify the chemical composition of the surface layer. It is therefore useful for diffusion studies as well.|
|PES, PhotoElectron Spectroscopy||Photoelectron spectroscopy (XPS and UPS) can also be used to measure the concentration of a particular element close to the surface|
Except for FFM, all other surface sensitive techniques require in-situ sample transfer from deposition to analysis to prevent surface contamination and degradation.