Scanning resistive probe microscopy: Imaging ferroelectric domains

Abstract

We report a resistive probe that detects electric field by field-induced resistance changes in a small resistive region at the apex of the tip and demonstrate a method of imaging ferroelectric domains at high speed, which is named scanning resistive probe microscopy (SRPM). We designed and fabricated the probe by self-aligning process that readily implemented the resistive region at the tip apex. In order to measure the field sensitivity, we contacted the probe with a thermally oxidized silicon sample and detected a 0.3% resistance change per volt applied to the sample. We obtained domain images of freshly cleaved triglycine sulfate (TGS) single crystal by contact mode SRPM. The operating voltage of the probe was 4 V and the scan rate and size were 2 Hz and 40×40 μm2, respectively. We controlled the polarization of Pb(Zr0.4Ti0.6)O3 (PZT) by applying voltage between the resistive tip and the bottom electrode of PZT, and acquired the domain images with the same tip at 2 Hz scan rate. By controlling and detecting the ferroelectric domains without an additional signal modulating system, we verified that the resistive probe could detect the ferroelectric domain at high speed and be used as a read/write head of a probe data storage system.