화학공학소재연구정보센터
Thin Solid Films, Vol.393, No.1-2, 204-209, 2001
The waveform separation of displacement current and tunneling current using a scanning vibrating probe
A measuring system that separates the both waveforms of displacement and tunneling current using a scanning vibrating probe is described. In the measuring system, the displacement and tunneling current flow periodically in accordance with the perpendicular vibration of the probe. The external circuit current is measured by oscilloscope and is separated into both waveforms of the displacement and tunneling current by utilizing the phase difference of them. The waveform of the displacement current is also analyzed by assuming the presence of excessive surface charges above the sample. Consequently, we can determine the mean distance between the probe and sample, and the offset voltage which is built up by excessive surface charges and work function difference of the probe and sample.