Magnetic field sensing element combining a circular vertical hall magnetic field sensing element with a planar hall element

Patent metadata

Field	Value
Publication number	US-9411023-B2
Application number	US-201414550202-A
Country	US
Kind code	B2
Filing date	Nov 21, 2014
Priority date	Sep 7, 2011
Publication date	Aug 9, 2016
Grant date	Aug 9, 2016

Abstract

A magnetic field sensor includes a circular vertical Hall (CVH) sensing element and at least one planar Hall element. The CVH sensing element has contacts arranged over a common implant region in a substrate. In some embodiments, the at least one planar Hall element is formed as a circular planar Hall (CPH) sensing element also having contacts disposed over the common implant region. A CPH sensing element and a method of fabricating the CPH sensing element are separately described.

First claim

What is claimed is:

1. A magnetic field sensing element arrangement, comprising:
a semiconductor substrate having first and second parallel major surfaces parallel to an x-y plane;
a plurality of planar Hall elements arranged as a circular planar Hall (CPH) structure, wherein each one of the plurality of planar Hall elements is arranged upon a common circular implant region in the first major surface of the semiconductor substrate, wherein the plurality of planar Hall elements is configured to generate a plurality of z output signals responsive to a magnetic field having a direction component in a z direction orthogonal to the x-y plane; and
a processing circuit disposed upon the semiconductor substrate and coupled to receive a signal representative of the plurality of z output signals, wherein each one of the plurality of planar Hall elements comprises a respective group of planar Hall element contacts, wherein the processing circuit is operable to process the plurality of planar Hall elements using a plurality of groups of the planar Hall element contacts to generate the signal representative of the plurality of z output signals, the processing circuit comprising a z direction component processor coupled to receive the signal representative of the plurality of z output signals and configured to generate an intermediate signal responsive to the direction component of the magnetic field in the z direction, wherein the intermediate signal comprises a DC signal component having a DC signal value responsive to a magnitude of the direction component of the magnetic field in the z direction, wherein the processing circuit is operable to generate an output signal indicative of the magnitude of the direction component of the magnetic field in the z direction responsive to the DC signal value.

2. A magnetic field sensing element arrangement, comprising:
a semiconductor substrate having first and second parallel major surfaces parallel to an x-y plane;
a plurality of planar Hall elements arranged as a circular planar Hall (CPH) structure, wherein each one of the plurality of planar Hall elements is arranged upon a common circular implant region in the first major surface of the semiconductor substrate, wherein the plurality of planar Hall elements is configured to generate a plurality of z output signals responsive to a magnetic field having a direction component in a z direction orthogonal to the x-y plane; and
a circular vertical Hall (CVH) sensing element disposed upon the common circular implant region, wherein the CVH sensing element comprises a plurality of vertical Hall element contacts, and wherein the plurality of planar Hall elements includes individual planar Hall elements interposed with the vertical Hall element contacts.

3. A magnetic field sensing element arrangement, comprising:
a semiconductor substrate having first and second parallel major surfaces parallel to an x-y plane;
a plurality of planar Hall elements arranged as a circular planar Hall (CPH) structure, wherein each one of the plurality of planar Hall elements is arranged upon a common circular implant region in the first major surface of the semiconductor substrate, wherein the plurality of planar Hall elements is configured to generate a plurality of z output signals responsive to a magnetic field having a direction component in a z direction orthogonal to the x-y plane; and
a circular vertical Hall (CVH) sensing element disposed upon a different common circular implant region in a major surface of the semiconductor substrate, wherein the CVH sensing element comprises a plurality of vertical Hall element contacts.

4. A method of fabricating a magnetic field sensing element arrangement, the method comprising:
forming a common circular implant region in a first major surface of a semiconductor substrate having the first and a second major parallel surface both parallel to an x-y plane;
forming, over the common circular implant region, a plurality of planar Hall elements arranged as a circular planar Hall (CPH) structure, wherein the plurality of planar Hall elements is configured to generate a plurality of z output signals responsive to a magnetic field having a direction component in a z direction orthogonal to the x-y plane; and
forming a circular vertical Hall (CVH) sensing element disposed upon the common circular implant region, wherein the CVH sensing element comprises a plurality of vertical Hall element contacts, and wherein the plurality of planar Hall elements includes individual planar Hall elements interposed with the vertical Hall element contacts,
wherein the common circular implant region comprises a common semiconducting region disposed beneath the plurality of planar Hall elements.

5. A method of fabricating a magnetic field sensing element arrangement, the method comprising:
forming a common circular implant region in a first major surface of a semiconductor substrate having the first and a second major parallel surface both parallel to an x-y plane;
forming, over the common circular implant region, a plurality of planar Hall elements arranged as a circular planar Hall (CPH) structure, wherein the plurality of planar Hall elements is configured to generate a plurality of z output signals responsive to a magnetic field having a direction component in a z direction orthogonal to the x-y plane; and
forming a circular vertical Hall (CVH) sensing element disposed upon a different common circular implant region in a major surface of the semiconductor substrate, wherein the CVH sensing element comprises a plurality of vertical Hall element contacts,
wherein the common circular implant region comprises a common semiconducting region disposed beneath the plurality of planar Hall elements.

6. The magnetic field sensing element arrangement of claim 1 , wherein the common circular implant region comprises n-type doping material and wherein the substrate is comprised of p-type material.

7. The magnetic field sensing element arrangement of claim 1 , wherein the semiconductor substrate comprises a silicon substrate.

8. The magnetic field sensing element arrangement of claim 1 , wherein the processing circuit is further operable to process each group of planar Hall element contacts in a multiplexed arrangement, wherein different ones of the planar Hall element contacts of each one of the plurality of planar Hall elements provide different ones of the plurality of z output signals at different times.

9. The magnetic field sensing element arrangement of claim 1 , further comprising a circular vertical Hall (CVH) sensing element disposed upon the common circular implant region, wherein the CVH sensing element comprises a plurality of vertical Hall element contacts, and wherein the plurality of planar Hall elements includes individual planar Hall elements interposed with the vertical Hall element contacts.

10. The magnetic field sensing element arrangement of claim 1 , further comprising a circular vertical Hall (CVH) sensing element disposed upon a different common circular implant region in a major surface of the semiconductor substrate, wherein the CVH sensing element comprises a plurality of vertical Hall element contacts.

11. The magnetic field sensor of claim 1 , wherein each one of the plurality of planar Hall elements of the CPH structure comprises a respective group of planar Hall element contacts, wherein ones of the plurality of planar Hall elements share planar Hall element contacts with other ones of the plurality of planar Hall elements.

12. The magnetic field sensing element arrangement of claim 2 , wherein the common circular implant region comprises n-type doping material and wherein the subs

Assignees

• Allegro Microsystems Llc

Inventors

• Friedrich Andreas P
• Foletto Andrea
• Pepka Gary T

Classifications

• G01R33/0052

  Manufacturing aspects; Manufacturing of single devices, i.e. of semiconductor magnetic sensor chips (devices based on galvano-magnetic effect or the like H10N50/85) · CPC title

• G01R33/072 Primary

  Constructional adaptation of the sensor to specific applications · CPC title

• G01R33/077 Primary

  Vertical Hall-effect devices · CPC title

• H01L43/065

  Electricity · mapped topic

• H10N52/101

  Semiconductor Hall-effect devices · CPC title