Thermal desorption behaviour of adsorbed materials on wafer surfaces

The influence of organic contamination on dielectric breakdown of a gate oxide was evaluated. Preventing air exposure during wafer processing from gate oxidation through poly Si CVD was shown to result in lower defect densities, and results obtained with a thermal desorption spectrum-atmospheric pressure ionization mass spectrometer showed that were the source of organic contamination gases released from plastic storage cases and that organic contaminants were not removed from the wafer surface at the processing temperature of poly Si CVD. We think the degradation of the gate oxide integrity has been interpreted in terms of local reduction of the gale oxide by the organic contamination at the interface between the gate oxide and the poly Si electrode.