A study of acoustoelectric effect in GaAs by fabricating interdigital transducer using electron beam lithography technique

Transverse acoustoelectric voltage (TAV) of Te-doped GaAs and n-GaAs/SI GaAs samples with photon energy and bias voltage is demonstrated. GaAs electronic properties were investigated using a surface acoustic wave (SAW) technique. The TAV was monitored across the GaAs sample by fabricating the interdigital transducer directly on the GaAs surface using electron beam lithography. In the processing, to protect the surface from contamination, the metal lift-off technique is also used. The TAV is developed due to the nonlinear interaction between the electric field accompanying SAW, and the free carriers near the GaAs surface. The TAV spectra are obtained to determining the bandgap energy and the Te-level which is observed at 300 K. It is also noticed that the TAV amplitude changes with bias voltage under the room illumination. However, when the illumination is turned off, the TAV does not change with bias voltage