Figure 2.

Cross-sectional SEM images of curro pores etched into (100) n-type InP. aND = 1·1017 cm−3, U = 7 V, bND = 8·1017 cm−3, U = 5.5 V, cND = 3·1018 cm−3, U = 3 V. A magnified view of the pore tips is shown in the insets. In d, e, and f a typical FFT IS spectrum is shown in form of a Nyquist plot recorded after 38 min of etching. The points represent the measured data, the line is calculated by fitting the measurements to the model given in Eq. 1. The measurement frequencies are indicated

Leisner et al. Nanoscale Research Letters 2010 5:1190-1194   doi:10.1007/s11671-010-9624-z