Vertical hall effect element with structures to improve sensitivity

摘要

A vertical Hall Effect element includes one or more of: a low voltage P-well region disposed at a position between pickups of the vertical Hall Effect element, Light-N regions disposed under the pickups, a pre-epi implant region, or two epi regions to result in an improved sensitivity of the vertical Hall Effect element. A method results in the vertical Hall Effect element having the improved sensitivity.

主权项

1. A Hall Effect element disposed over a substrate, the Hall Effect element comprising:
an N-type epitaxial layer disposed over the substrate; a plurality of pickups implanted and diffused into the epitaxial layer, adjacent pairs of the plurality of pickups separated by separation regions, each one of the plurality of pickups comprising a respective N-plus type diffusion; a plurality of Light-N regions implanted and diffused into the epitaxial layer, each one of the plurality of Light-N regions disposed and a respective one of the plurality of pickups, wherein the Hall Effect element is configured to generate a Hall voltage between at least one pair of the plurality of pickups, wherein the Hall voltage is most responsive to a magnetic field directed parallel to a major surface of the substrate; a Light-P region implanted and diffused into the epitaxial layer, wherein the Light-P region extends into the separation regions; a P-type buried layer region disposed under the epitaxial layer, implanted and diffused into the substrate, and surrounding the plurality of pickups, wherein the P-type buried layer region is diffused from the substrate into the epitaxial layer; and a P-well region implanted and diffused into the epitaxial layer and surrounding the plurality of pickups at an upper surface of the epitaxial layer, wherein the P-type buried layer region and the P-well region are coupled in a direction vertical to the substrate so as to for a harrier to electrical charges within the epitaxial layer, wherein the Hall Effect element is configured to pass a drive current between at least two of the plurality of pickups, and wherein a depth of the Light-P region extending into the separation regions is selected to force the drive current deeper and more vertically into the epitaxial layer in relation to the major surface of the substrate, resulting in a more sensitive Hall Effect element.