Nano-scale ferroelectric domain differentiation in periodically poled lithium niobate with auger electron spectroscopy

Abstract

A new method for characterizing lithium niobate +/-Z ferroelectric polarization domains using Auger electron spectroscopy (AES) is presented. The domains of periodically poled samples are found to be differentiable using the peak amplitude of the Auger oxygen KLL transition, with -Z domains having a larger peak-amplitude as compared to +Z domains. The peak amplitude separation between domains is found to be dependent on the primary beam current, necessitating a balance between the insulating samples charging under the primary beam and achieving sufficient signal to noise in amplitude separation. AES amplitude-based domain characterization is demonstrated for fields of view (FOV) ranging from 1 𝜇m to 78 𝜇m. Domain spatial resolution of 91 nm is demonstrated at 1 𝜇m FOV.