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

• US 9,411,023 B2
• Filed: 11/21/2014
• Issued: 08/09/2016
• Est. Priority Date: 09/07/2011
• Status: Active Grant

• Current Assignee: Allegro Microsystems Incorporated (Sanken Electric Company Limited)
• Original Assignee: Allegro Microsystems Incorporated (Sanken Electric Company Limited)
• Inventors: Friedrich, Andreas P., Foletto, Andrea, Pepka, Gary T.
• Primary Examiner(s): LEDYNH, BOT L
• Application Number:
  US14/550,202
• Publication Number:
  US 20150077100A1
• Time in Patent Office: 627 Days
• Field of Search: 324/251
• US Class Current: 1/1
• CPC Class Codes: G01R 33/0052 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 Class Codes: G01R 33/072 Constructional adaptation of the sensor to specific applications
• CPC Class Codes: G01R 33/077 Vertical Hall-effect devices
• CPC Class Codes: H10N 52/101 Semiconductor Hall-effect devices

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.

Claims

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.

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.

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.

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

13. The magnetic field sensing element arrangement of claim 2, wherein the semiconductor substrate comprises a silicon substrate.

14. The magnetic field sensing element arrangement of claim 2, further comprising 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, 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.

15. The magnetic field sensing element arrangement of claim 14, wherein the processing circuit comprises 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.

16. The magnetic field sensor of claim 2, 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.

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.

17. The magnetic field sensing element arrangement of claim 3, wherein the common circular implant region comprises n-type doping material and wherein the substrate is comprised of p-type material.

18. The magnetic field sensing element arrangement of claim 3, wherein the semiconductor substrate comprises a silicon substrate.

19. The magnetic field sensing element arrangement of claim 3, further comprising 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.

20. The magnetic field sensing element arrangement of claim 19, 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.

21. The magnetic field sensing element arrangement of claim 19, wherein the processing circuit comprises 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.

22. The magnetic field sensor of claim 3, 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.

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.

23. The method of claim 4, wherein each one of the plurality of planar Hall elements of the CPH structure comprises a respective group of planar Hall element contacts, the method further comprising:

sharing planar Hall element contacts between ones of 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.

24. The method of claim 5, wherein each one of the plurality of planar Hall elements of the CPH structure comprises a respective group of planar Hall element contacts, the method further comprising:

sharing planar Hall element contacts between ones of the plurality of planar Hall elements.