A microelectronic device has a Hall sensor that includes a Hall plate in a semiconductor material. The Hall sensor includes contact regions in the semiconductor material, contacting the Hall plate. The Hall sensor includes an isolation structure with a dielectric material contacting the semiconductor material, on at least two opposite sides of each of the contact regions. The isolation structure is laterally separated from the contact regions by gaps. The Hall sensor further includes a conductive spacer over the gaps, the conductive spacer being separated from the semiconductor material by an insulating layer.