Vertical hall effect device

• US 20060157809A1
• Filed: 01/20/2005
• Published: 07/20/2006
• Est. Priority Date: 01/20/2005
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Biard, James R., Morales, Gilberto, Alimi, Yousef M.
• Granted Patent: US 7,205,622 B2
• Time in Patent Office: Days
• US Class Current: 257/421
• 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 Hall effect elements formed within said epitaxial layer and below said oxide layer, wherein said plurality of Hall effect elements 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 element among said plurality of Hall effect elements; and

a plurality of field plates formed above said oxide layer, wherein 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 plurality of Hall effect elements comprises a lightly doped N-epitaxial material.

3. The apparatus of claim 1 further comprising two ground contacts formed within said epitaxial layer.

4. The apparatus of claim 3 wherein said two ground contacts comprise N+ type regions.

5. The apparatus of claim 1 wherein at least one Hall effect element among said plurality of Hall effect elements produces a positive voltage in response to a magnetic field, thereby providing a voltage-sensing component thereof.

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

7. The apparatus of claim 1 wherein at least one Hall effect element among said plurality of Hall effect elements produces a negative voltage in response to a magnetic field, thereby providing a voltage-sensing component thereof.

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

9. The apparatus of claim 1 further comprising a voltage contact formed centrally within said epitaxial layer.

10. The apparatus of claim 9 wherein said voltage contact comprises an N+ type region.

11. 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 Hall effect elements formed as N+ type regions within said N−

type epitaxial layer and below said oxide layer, wherein said plurality of Hall effect elements sense the components of an arbitrary magnetic field in the plane of the substrate and perpendicular to the current flow in the hall element; and

wherein at least one Hall effect element among said plurality of Hall effect elements provides a positive sense voltage and at least one Hall effect element among said plurality of Hall effect elements provides a negative sense voltage in response to a magnetic field; and

a plurality of field plates formed above said oxide layer, wherein 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.

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