Diode current detection of extended x-ray absorption fine structure in gallium arsenide

Measurement of diode photocurrent represents a new method for obtaining extended x-ray absorption fine structure (EXAFS) information specific to the junction region of a diode. EXAFS measurements at Ga and As K edges of an aluminum-on-GaAs Schottky diode have been used to demonstrate this new technique. The spectra observed in the diode current arise mainly from x-ray absorption events within 2 μm of the diode junction, i.e., within a minority carrier diffusion length of the approximately 600-Å-wide depletion region. The diode current EXAFS are consistent with EXAFS obtained from fluorescence measurements.