Title :
Effect of SAW frequency on transverse acoustoelectric voltage measurements
Author :
Palma, F. ; de Cesare, Giampiero ; Das, P. ; Abbate, A.
Author_Institution :
Dept. of Electron., Rome Univ., Italy
Abstract :
The effect of trapped charges on transverse acoustoelectric voltage is investigated with the aim of extending the use of this measurement to the study of semiconductors with a high defect density, e.g. amorphous materials. Even when SAW (surface acoustic wave) frequencies range from 50 to 100 MHz, the effect due to charge trapping can be relevant. This effect has been verified on a damaged Si/SiO2 structure, measuring transverse acoustoelectric voltage (TAV) vs. bias voltage at two different frequencies using the fundamental and odd harmonics of the SAW delay line. Measurements show that TAV vs V plots obtained at the fundamental frequency are different from those obtained at the higher frequency. This variation is related to the different influences of traps at low and high frequency. A theoretical model is proposed to explain this frequency dependence
Keywords :
acoustoelectric effects; electric potential; elemental semiconductors; semiconductor-insulator boundaries; silicon; silicon compounds; surface acoustic waves; 50 to 100 MHz; Si-SiO2; bias voltage; charge trapping; frequency dependence; fundamental frequency; semiconductor; surface acoustic wave frequency; transverse acoustoelectric voltage measurements; trapped charges; Acoustic measurements; Acoustic waves; Amorphous materials; Current measurement; Delay lines; Density measurement; Frequency dependence; Frequency measurement; Surface acoustic waves; Voltage measurement;
Conference_Titel :
Ultrasonics Symposium, 1989. Proceedings., IEEE 1989
Conference_Location :
Montreal, Que.
DOI :
10.1109/ULTSYM.1989.66969
