Capacitance Transient X-ray Absorption Spectroscopy of semiconducting structures

A new technique for the detection of X-ray absorption in multilayer structures, Capacitance Transient X-ray Absorption Spectroscopy (CapTXAS), has been developed. CapTXAS technique utilizes the fact that excess carriers generated in the semiconductor structure under the X-ray excitation can be captured with deep level electronic states at the structure interface(s) within the space charge region of the Schottky-diode giving rise to the diode capacitance changes. Short periodical refilling electric pulses are applied to the structure to define the initial trap occupancy and the first derivative of the capacitance transients after the bias voltage recovery is measured. We installed this technique at BESSY Russian–German Beam Line and applied to the measurements on two test semiconductor structures: Au–/nickel–phtalocyanine/–silicon and Al-bonded silicon wafer.