Charged particle activation analysis with cyclotron

The electronic properties of semiconductor are governed in large part by the nature and the residual impurities, and accurate analytical methods at trace level are needed as a complement to electrical, optical and structural methods of characterization. Radioactivation methods in general are essential for trace analysis because of their accuracy; among these methods, CPAA (Charged Particles Activation Analysis) is especially suited for the determination of light elements (C, N, O) which often are the major residual impurities of semiconductors. CPAA is essentially a contaminant free analysis method and maintains with range of linearity till ppb region comparing with decaid known activated standard sample like SiO2. CPAA can also be used advantageously for other heavier element if needed, and sometimes be a complement to neutron activation, or even compete with it. A few example of analysis of light elements in GaAs and Si will be given by the use of a small size cyclotron of model 370 which is installed at Tokyo Works together with potential application to analysis of oxygen content of superconductive oxide YBa2Cu3O7-δ. (author)