Vertical hall effect device

• US 7,205,622 B2
• Filed: 01/20/2005
• Issued: 04/17/2007
• Est. Priority Date: 01/20/2005
• Status: Expired due to Fees

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Biard, James R., Morales, Gilberto, Alimi, Yousef M.
• Primary Examiner(s): Baumeister; B. William
• Assistant Examiner(s): Fulk; Steven J.
• Application Number:
  US11/038,881
• Publication Number:
  US 20060157809A1
• Time in Patent Office: 817 Days
• Field of Search: 257/22, 257/27, 257/26, 257/422, 257/426, 257/427, 257/E29.323, 438/48, 324/207.2
• US Class Current: 257/422
• CPC Class Codes: G01R 33/077 Vertical Hall-effect devices
• CPC Class Codes: H10N 52/101 Semiconductor Hall-effect devices

Abstract

A vertical Hall effect apparatus, including methods thereof. A substrate layer can be provided upon which an epitaxial layer is formed. The epitaxial layer is surrounded vertically by one or more isolation layers. Additionally, an oxide layer can be formed above the epitaxial layer. A plurality of Hall effect elements can be formed within the epitaxial layer(s) and below the oxide layer, wherein the Hall effect elements sense the components of an arbitrary magnetic field in the plane of the wafer and perpendicular to the current flow in the hall element. A plurality of field plates can be formed above the oxide layer to control the inherited offset due to geometry control and processing of the vertical Hall effect apparatus, while preventing the formation of an output voltage of the vertical Hall effect apparatus at zero magnetic fields thereof.

Claims

1. A vertical Hall effect apparatus, comprising:

a substrate layer upon which an epitaxial layer is formed, wherein said epitaxial layer is surrounded vertically by an isolation layer and wherein an oxide layer is formed above said epitaxial layer;

a plurality of adjacent contacts arranged side by side in a row within said epitaxial layer and separated by regions of said epitaxial layer;

wherein said plurality of contacts comprise;

a pair of Hall effect sensing contacts formed below said oxide layer, wherein said pair of Hall effect sensing contacts senses the components of an arbitrary magnetic field in a plane of said substrate and perpendicular to a current flow in at least one Hall effect sensing contact among said pair of Hall effect sensing contacts, and;

a voltage contact (Vcc) formed centrally within said epitaxial layer between said pair of Hall effect sensing contacts; and

a pair of ground contacts formed outwardly within said epitaxial layer, each of said ground contacts being located adjacent respective Hall effect sensing contacts; and

a plurality of field plates formed above said oxide layer, wherein each of said plurality of field plates is located above a respective one of said epitaxial regions and between a respective immediately adjacent pair of said plurality of contacts such that said plurality of field plates control an inherited offset due to geometry control and processing of said vertical Hall effect apparatus, while preventing the formation of an output voltage of said vertical Hall effect apparatus at zero magnetic fields thereof.

2. The apparatus of claim 1 wherein said pair of Hall effect sensing contacts comprises a lightly doped N-epitaxial material.

3. The apparatus of claim 1 wherein said pair of ground contacts comprise N+ type regions.

4. The apparatus of claim 1 wherein one of said Hall effect sensing contacts among said pair of Hall effect sensing contacts produces a positive voltage in response to a magnetic field, thereby providing a voltage-sensing component thereof.

5. The apparatus of claim 4 wherein said voltage sensing component comprises an N+ type region.

6. The apparatus of claim 1 wherein one of said Hall effect sensing contacts among said pair of Hall effect sensing contacts produces a negative voltage in response to a magnetic field, thereby providing a voltage-sensing component thereof.

7. The apparatus of claim 6 wherein said voltage sensing component comprises an N+ type region.

8. The apparatus of claim 1 wherein said voltage contact comprises an N+ type region.

9. A vertical Hall effect apparatus, comprising:

a substrate layer upon which an N-type epitaxial layer is formed, wherein said epitaxial layer is surrounded vertically by an isolation layer and wherein an oxide layer is formed above said N-type epitaxial layer;

a plurality of adjacent contacts arranged side by side in a row within said N-type epitaxial layer and separated by regions of said N-type epitaxial layer;

wherein said plurality of contacts comprise;

pair of Hall effect sensing contacts formed as N+ type regions within said N-type epitaxial layer and below said oxide layer, wherein said pair of Hall effect sensing contacts sense the components of an arbitrary magnetic field in the plane of the substrate and perpendicular to the current flow in the hall sensing contact, wherein one of said Hall effect sensing contacts among said pair of Hall effect sensing contacts provides a positive sense voltage and the other of said Hall effect sensing contacts among said pair of Hall effect sensing contacts provides a negative sense voltage in response to a magnetic field

a voltage contact (Vcc) formed centrally within said N-type epitaxial layer between said pair of Hall effect sensing contacts; and

a pair of rround contacts formed outwardly within said N-type epitaxial layer, each of said ground contacts being located adjacent respective Hall effect sensing contacts; and

a plurality of field plates formed above said oxide layer, wherein each of said plurality of field plates is located above a respective one of said epitaxial regions and between a respective immediately adjacent pair of said plurality of contacts such that said plurality of field plates control an inherited offset due to geometry control and processing of said vertical Hall effect apparatus, while preventing the formation of an output voltage of said vertical Hall effect apparatus at zero magnetic fields thereof.