Optical real time signal processors and semiconductor surface and semiconductor-electrolyte interface study using acoustic surface wave

The research work can be broadly classified into four categories: (1) a new method for the determination of electrical surface properties of semiconductors using acoustic surface wave delay lines, (2) a new method for the determination of electrical properties of semiconductor-electrolyte interface, (3) optical signal processing using surface acousto-optic interaction, and (4) studies on hot electron properties of semiconductors. The method of surface property determination is sensitive and simple and requires no physical contact with semiconductor surface. The SAW probing technique for electrical characterization of semiconductors has been performed at low temperature down to 77 K. Results obtained with GaAs agree with the theoretical expectations. Oxides have been anodically grown on GaAs and interface properties are being evaluated using the SAW probe. The activation of ion-implanted impurities in silicon by thermal annealing is being monitored by the SAW probing technique. Numerical computations of the transverse acoustoelectric voltage (TAV) have been performed which can be used to quantitatively evaluate the semiconductor properties non-destructively from the experimental TAV data. In connection with semiconductor-electrolyte interface study, the electrical properties of CdS-NiCl2 interface have been determined using the surface acoustic wave technique.