ELECTRICAL AND DEFECT CHARACTERIZATION OF N-TYPE GAAS IRRADIATED WITHALPHA-PARTICLES USING A VANDEGRAAFF ACCELERATOR AND AN AM-241 RADIO-NUCLIDE SOURCE

Radiation damage effects are studied in OMVPE n-GaAs for a wide range of alpha (alpha) particle fluences, using an americium-241 (Am-241) ra dio-nuclide and a linear van de Graaff accelerator as the particle sou rces. The samples are irradiated at 300 K, after fabricating palladium Schottky barrier diodes (SBDs) on the 1.2 x 10(16) cm-3 Si doped epit axial layers. The radiation induced defects are characterized using co nventional deep level transient spectroscopy (DLTS). A correlation is made between the change in SBD characteristics and the quantity and ty pe of defects introduced during alpha-particle irradiation. It is show n that the two parameters most susceptible to this irradiation are the reverse leakage current of the SBDs and the free carrier density of t he epilayer. The introduction rate and the ''signatures'' of the alpha -particle irradiation induced defects are calculated and compared to t hose of similar defects introduced during electron irradiation.