Hall effect device with trench about a micron or greater in depth

A Hall effect device, comprising:

• an implantation layer;
• an epitaxial layer having a first portion and a second portion, wherein the implantation layer is below the first portion of the epitaxial layer;
• a trench filled with a dielectric material and extending from a top surface of the epitaxial layer into the implantation layer, the trench in contact with the second portion of the epitaxial layer, wherein the trench defines an enclosed region;
• wherein the first portion of the epitaxial layer and the implantation layer are surrounded by the trench within the enclosed region, and wherein the first and second portions of the epitaxial layer are on opposite sides of the trench, wherein the Hall effect device comprises vertical Hall elements outside of the enclosed region and the trench and a planar Hall element in the enclosed region,
• a well layer abutting the implantation layer in the enclosed region and abutting the second portion of the epitaxial layer for the vertical Hall elements, wherein the trench extends into the well layer;
• a substrate under the well layer;
• a contact pad located on the epitaxial layer;
• and
• wherein a current bias on the contact pad generates a current that flows into the first portion of the epitaxial layer and into the implantation layer,
• wherein the current moves in a vertical direction through the second portion of the epitaxial layer, and
• wherein the trench reduces the current from traveling in a lateral direction orthogonal to the vertical direction and enables the current to travel in the vertical direction.