Modem analytical techniques are useful to characterize oxide films and to study oxide growth processes. This paper will summarize some of our work on the high temperature oxidation of both metals and semiconductors. Systems considered include binary III-V semiconductors, e.g. GaAs, which unlike silicon does not normally form high-quality native oxide. For GaAs, the influence of deuterium in the substrate and surface platinum have been evaluated with respect to oxide growth. Both aluminum-containing alloys (FeCrAl and NiAl) and semiconductors (AlGaAs, InAlAs and InAlP) are included. The objective is to produce good quality protective and insulating aluminum-containing oxides. In these studies, the application of several modem surface- analytical techniques, particularly Auger electron spectroscopy, X-ray photoelectron spectroscopy and secondary ion mass spectrometry, complemented by other techniques, e.g. transmission electron microscopy and X-ray analysis provides useful information on the chemical composition of the oxides and leads to a better understanding of oxidation and corrosion phenomena. In the case of AlGaAs and InAlP, thermal oxidation produces aluminum-containing oxides that have good insulating characteristics which makes the oxide films potentially useful for some device applications.