Spatially resolved dielectric loss at the Si/SiO$_2$ interface

TL;DR

This study uses high-resolution atomic force microscopy to analyze dielectric loss at the Si/SiO2 interface, revealing significant spatial heterogeneity in charge organization timescales related to interfacial trap states.

Contribution

It introduces a nm-scale spatially resolved method to measure dielectric susceptibility at the Si/SiO2 interface, highlighting heterogeneity in charge dynamics.

Findings

Charge organization timescales range from 1-150 ns.

Dielectric loss is highly spatially heterogeneous.

Interfacial trap states significantly influence local dielectric properties.

Abstract

The Si/SiO$_2$ interface is populated by isolated trap states which modify its electronic properties. These traps are of critical interest for the development of semiconductor-based quantum sensors and computers, as well as nanoelectronic devices. Here, we study the electric susceptibility of the Si/SiO$_2$ interface with nm spatial resolution using frequency-modulated atomic force microscopy to measure a patterned dopant delta-layer buried 2 nm beneath the silicon native oxide interface. We show that surface charge organization timescales, which range from 1-150 ns, increase significantly around interfacial states. We conclude that dielectric loss under time-varying gate biases at MHz and sub-MHz frequencies in metal-insulator-semiconductor capacitor device architectures is highly spatially heterogeneous over nm length scales. Supplemental GIFs can be found at https://doi.org/10.6084/m9.figshare.25546687