Особенности измерения поверхностного распределения электрического потенциала локальным зондом на основе полевого транзистора с каналом-нанопроводом

Abstract

The non-destructive method of scanning probe microscopy for simultaneous measurement of surface topography and distribution of the electric field (charge, potential) is demonstrated. The surface is scanned by the tuning fork method, the interaction with the surface is carried out by the sharp edge of the silicon chip mounted on one of the legs of the quartz resonator. The detection of electric potentials was carried out using a field-effect transistor with a nanowire channel formed at the tip of the probe. Due to the low quality factor of the oscillatory system, scanning by standard algorithms of probe movement above the surface led to rapid wear and even destruction of the tip of the probe. An original scanning algorithm was developed that minimizes the interaction time between the probe and the object under study. The minimum time at each scanning surface point was 1.0-1.6 ms - this time was determined by the response time of the field-effect transistor to a change in the detected electric field (the measurement time for one scan was 20-30 min). The spatial resolution of the method was 10 nm and 20 nm for measuring the topography and field profile of the sample, respectively. The field resolution of the fabricated chips was in the range of 2-5 mV and was determined by the sensitivity of the nanowire of the field effect transistor and the distance from the nanowire to the tip of the probe.