New geometries for high spatial resolution hall probes

TL;DR

This paper investigates the Hall response function of symmetric and asymmetric planar Hall effect devices using scanning techniques, demonstrating how tailored geometries can significantly improve spatial resolution.

Contribution

It introduces new asymmetric geometries for Hall sensors and demonstrates a method to pattern sensors with enhanced spatial resolution using Focused Ion Beam technology.

Findings

Response function peaks above the constriction, matching simulations

Asymmetric geometries improve spatial resolution

Focused Ion Beam enables precise sensor patterning

Abstract

The Hall response function of symmetric and asymmetric planar Hall effect devices is investigated by scanning a magnetized tip above a sensor surface while simultaneously recording the topography and the Hall voltage. Hall sensor geometries are tailored using a Focused Ion Beam, in standard symmetric and new asymmetric geometries. With this technique we are able to reduce a single voltage probe to a narrow constriction 20 times smaller than the other device dimensions. We show that the response function is peaked above the constriction, in agreement with numerical simulations. The results suggest a new way to pattern Hall sensors for enhanced spatial resolution.