Magnetic sensor and method for detecting magnetic field

• US 20070290682A1
• Filed: 01/04/2007
• Published: 12/20/2007
• Est. Priority Date: 01/13/2006
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Fujii, Tetsuo, Oohira, Satoshi
• Granted Patent: US 7,511,484 B2
• Time in Patent Office: Days
• US Class Current: 324/251
• CPC Class Codes: G01R 33/07 Hall effect devices
• CPC Class Codes: G01R 33/075 Hall devices configured for spinning current measurements
• CPC Class Codes: G01R 33/077 Vertical Hall-effect devices
• CPC Class Codes: H10N 52/101 Semiconductor Hall-effect devices

Abstract

A magnetic sensor includes: a substrate; a semiconductor region; a magnetic field detection portion; a pair of first electrodes; and two pairs of second electrodes. One pair of second electrodes includes first and second terminals, and the other pair includes third and fourth terminals. The first and third terminals are disposed on one side, and the second and fourth terminals are disposed on the other side. The first and fourth terminals are electrically coupled, and the second and third terminals are electrically coupled. The magnetic field detection portion and the first and second electrodes provide a vertical Hall element. One of the first and second electrodes supplies a driving current, and the other one detects the Hall voltage.

Claims

1. A magnetic sensor comprising:

a substrate;

a semiconductor region disposed in the substrate and having a predetermined conductive type;

a magnetic field detection portion disposed in the semiconductor region;

a pair of first electrodes disposed on a surface of the semiconductor region; and

two pairs of second electrodes disposed on the surface of the semiconductor region, wherein one pair of second electrodes sandwiches one of first electrodes, and the other pair of second electrodes sandwiches the other one of first electrodes, wherein the one pair of second electrodes includes first and second terminals, and the other pair of second electrodes includes third and fourth terminals,

the first and third terminals are disposed on one side of a line connecting between the first electrodes, and the second and fourth terminals are disposed on the other side of the line, the first and fourth terminals are electrically coupled with a first wiring, and the second and third terminals are electrically coupled with a second wiring,

the magnetic field detection portion, the first electrodes and the second electrodes provide a vertical Hall element, the vertical Hall element generates a Hall voltage corresponding to a magnetic field when the magnetic field in parallel to the surface of the substrate is applied to the magnetic field detection portion, and a driving current is supplied to the magnetic field detection portion, and

one of the first and second electrodes supplies the driving current, and the other one of the first and second electrodes detects the Hall voltage.

2. The sensor according to claim 1, wherein

a distance between the first and third terminals is substantially equal to a distance between the second and fourth terminals, and

a distance between the first electrodes is longer than the distance between the first and third terminals.

3. The sensor according to claim 1, wherein

the one pair of second electrodes further includes fifth and sixth terminals, and the other pair of second electrodes further includes seventh and eighth terminals,

the fifth and sixth terminals sandwich the first and second terminals and the one of first electrodes, and the seventh and eighth terminals sandwich the third and fourth terminals and the other one of first electrodes,

the fifth and seventh terminals are disposed on the one side of the line connecting between the first electrodes, and the sixth and eighth terminals are disposed on the other side of the line, and

the fifth and eighth terminals are electrically coupled with a third wiring, and the sixth and seventh terminals are electrically coupled with a fourth wiring.

4. The sensor according to claim 1, wherein

the one of first electrodes includes first, second and third pads, and the other one of first electrodes includes fourth, fifth and sixth pads,

the first and second terminals sandwich the first pad, and the third and fourth terminals sandwich the fourth pad,

the second and third pads sandwich the first and second terminals and the first pad, and the fifth and sixth pads sandwich the third and fourth terminals and the fourth pad,

the first and third terminals and the second and fifth pads are disposed on the one side of the line connecting between the first and fourth pads, and the second and fourth terminals and the third and sixth pads are disposed on the one side of the line, and

the first, fifth and sixth pads are electrically coupled with a fifth wiring, and the second, third and fourth pads are electrically coupled with a sixth wiring.

5. The sensor according to claim 1, wherein

the first and second terminals are arranged in a line symmetrical manner with respect to the line connecting between the first electrodes, and

the third and fourth terminals are arranged in a line symmetrical manner with respect to the line.

6. The sensor according to claim 1, further comprising:

a separation wall disposed in the semiconductor region, wherein

the substrate includes a semiconductor substrate having a first conductive type,

the semiconductor region is a diffusion layer having a second conductive type,

the separation wall has a depth, which is sallower than a depth of the semiconductor region,

the separation wall electrically divides the semiconductor region into first and second semiconductor regions,

the one of first electrodes and the first and second terminals are disposed in the first semiconductor region, and

the other one of first electrodes and the third and fourth terminals are disposed in the second semiconductor region.

7. The sensor according to claim 6, wherein

the separation wall is a diffusion layer having the first conductive type.

8. The sensor according to claim 6, wherein

the separation wall is a trench separation region having a trench and an insulation film in the trench.

9. The sensor according to claim 8, wherein

the trench separation region further includes a diffusion film having the first conductive type, and

the diffusion film covers an inner wall of the trench so that the insulation film is disposed in the trench through the diffusion film.

10. The sensor according to claim 6, wherein

the substrate further includes a support substrate and an insulation layer,

the semiconductor substrate, the insulation layer and the support substrate are stacked in this order, and

the semiconductor region is disposed in the semiconductor substrate.

11. The sensor according to claim 10, wherein

the support substrate has a predetermined fixed electric potential.

12. The sensor according to claim 1, further comprising:

first and second separation walls disposed in the substrate and connected to each other, wherein

the substrate includes a support substrate having a first conductive type and a semiconductor layer having a second conductive type,

the semiconductor layer is disposed on the support substrate, the semiconductor region is disposed in the semiconductor layer,

the first separation wall surrounds the semiconductor region so that the first separation wall electrically separates the semiconductor region from the semiconductor layer,

the second separation wall is disposed in the semiconductor region so that the second separation wall provides a current path near a bottom of the semiconductor region,

the second separation wall electrically divides the semiconductor region into first and second semiconductor regions,

the one of first electrodes and the first and second terminals are disposed in the first semiconductor region, and

the other one of first electrodes and the third and fourth terminals are disposed in the second semiconductor region.

13. The sensor according to claim 12, further comprising:

an embedded layer disposed between the semiconductor layer and the support substrate, wherein

the embedded layer has the second conductive type and an impurity concentration higher than an impurity concentration of the semiconductor region,

the embedded layer provides the current path, and

the second separation wall contacts the embedded layer.

14. The sensor according to claim 12, wherein

the second separation wall is a diffusion layer having the first conductive type.

15. The sensor according to claim 12, wherein

the second separation wall is a trench separation region having a trench and an insulation film in the trench.

16. The sensor according to claim 12, wherein

the first separation wall has a depth, which is deeper than a depth of the second separation wall.

17. The sensor according to claim 1, further comprising:

first and second separation walls disposed in the substrate and connected to each other, wherein

the substrate includes a semiconductor layer having a first conductive type, an insulation layer and a support substrate having a second conductive type,

the semiconductor layer, the insulation layer and the support substrate are stacked in this order,

the semiconductor region is disposed in the semiconductor layer,

the first separation wall surrounds the semiconductor region so that the first separation wall electrically separates the semiconductor region from the semiconductor layer,

the second separation wall is disposed in the semiconductor region so that the second separation wall provides a current path near a bottom of the semiconductor region,

the second separation wall electrically divides the semiconductor region into first and second semiconductor regions,

the one of first electrodes and the first and second terminals are disposed in the first semiconductor region, and

the other one of first electrodes and the third and fourth terminals are disposed in the second semiconductor region.

18. The sensor according to claim 17, wherein

the support substrate has a predetermined fixed electric potential.

19. The sensor according to claim 17, wherein

the first and second separation walls are diffusion layers having the first conductive type.

20. The sensor according to claim 17, wherein

the first and second separation walls are trench separation regions having a trench and an insulation film in the trench.

21. The sensor according to claim 20, wherein

the trench separation region further includes a diffusion film having the first conductive type, and

the diffusion film covers an inner wall of the trench so that the insulation film is disposed in the trench through the diffusion film.

22. The sensor according to claim 17, wherein

the first separation wall has a depth, which is deeper than a depth of the second separation wall.

23. The sensor according to claim 1, further comprising:

a planar electrode disposed on the surface of the substrate, wherein

the planar electrode is electrically separated from the substrate with an insulation film.

24. The sensor according to claim 23, wherein

the planar electrode covers at least the semiconductor region, and

the planar electrode has a predetermined fixed electric potential.

25. The sensor according to claim 1, further comprising:

a field oxide film having a LOCOS structure disposed on the surface of the substrate, wherein

the field oxide film covers at least the semiconductor region.

26. The sensor according to claim 1, further comprising:

a first conductive type film disposed on the surface of the substrate, wherein

the first conductive type film covers at least the semiconductor region.

27. The sensor according to claim 1, further comprising:

a plurality of semiconductor regions;

a plurality of magnetic field detection portions disposed in the semiconductor regions;

a plurality of pairs of first electrodes disposed on the surface of the semiconductor region; and

a plurality of two pairs of second electrodes disposed on the surface of the semiconductor region, wherein

each magnetic field detection portion, each pair of first electrodes and each two pairs of second electrodes provide a vertical Hall element so that a plurality of vertical Hall elements are disposed in the substrate, and

the vertical Hall elements are electrically coupled in parallel together so that an offset voltage of the sensor is reduced.

28. The sensor according to claim 27, wherein

one line connecting between the first electrodes in one of the vertical Hall elements is in parallel to another line connecting between the first electrodes in another one of the vertical Hall elements.

29. The sensor according to claim 28, wherein

the substrate provides a semiconductor chip having four sides, and

an angle between the one line in the one of the vertical Hall elements and one side of the semiconductor chip is almost 45 degrees.

30. The sensor according to claim 27, wherein

one line connecting between the first electrodes in one of the vertical Hall elements is perpendicular to another line connecting between the first electrodes in another one of the vertical Hall elements.

31. The sensor according to claim 30, further comprising:

a lateral Hall element for detecting a magnetic field perpendicular to the surface of the substrate, wherein

each vertical Hall element detects the magnetic field in parallel to the surface of the substrate, and

the vertical Hall elements and the lateral Hall element detect the magnetic field three-dimensionally.

32. The sensor according to claim 30, wherein

the first electrodes in the one of the vertical Hall elements is in common with the first electrodes in the another one of the vertical Hall elements.

33. A magnetic sensor comprising:

a substrate;

a semiconductor region disposed in the substrate and having a predetermined conductive type;

a magnetic field detection portion disposed in the semiconductor region;

a first electrode having first, second and third pads, which are disposed on a surface of the semiconductor region and aligned on a line connecting between the first and third pads so that the first and third pads sandwich the second pad; and

a second electrode having first to sixth terminals disposed on the surface of the semiconductor region, wherein the first and second terminals sandwich the first pad, the third and fourth terminals sandwich the second pad, and the fifth and sixth terminals sandwich the third pad, wherein

the first, third and fifth terminals are disposed on one side of a line connecting between the first and third pads, and the second, fourth and sixth terminals are disposed on the other side of the line,

the first, fourth and fifth terminals are electrically coupled with a seventh wiring, and the second, third and sixth terminals are electrically coupled with an eighth wiring,

the magnetic field detection portion, the first electrode and the second electrode provide a vertical Hall element,

the vertical Hall element generates a Hall voltage corresponding to a magnetic field when the magnetic field in parallel to the surface of the substrate is applied to the magnetic field detection portion, and a driving current is supplied to the magnetic field detection portion, and

one of the first and second electrodes supplies the driving current, and the other one of the first and second electrodes detects the Hall voltage.

34. The sensor according to claim 33, wherein

the first and second terminals are arranged in a line symmetrical manner with respect to the line connecting between the first and third pads,

the third and fourth terminals are arranged in a line symmetrical manner with respect to the line, and

the fifth and sixth terminals are arranged in a line symmetrical manner with respect to the line.

35. The sensor according to claim 33, further comprising:

a separation wall disposed in the semiconductor region, wherein

the substrate includes a semiconductor substrate having a first conductive type,

the semiconductor region is a diffusion layer having a second conductive type,

the separation wall has a depth, which is sallower than a depth of the semiconductor region,

the separation wall electrically divides the semiconductor region into first to third semiconductor regions,

the first pad and the first and second terminals are disposed in the first semiconductor region,

the second pad and the third and fourth terminals are disposed in the second semiconductor region, and

the third pad and the fifth and sixth terminals are disposed in the third semiconductor region.

36. The sensor according to claim 35, wherein

the separation wall is a diffusion layer having the first conductive type.

37. The sensor according to claim 35, wherein

the separation wall is a trench separation region having a trench and an insulation film in the trench.

38. The sensor according to claim 37, wherein

the trench separation region further includes a diffusion film having the first conductive type, and

the diffusion film covers an inner wall of the trench so that the insulation film is disposed in the trench through the diffusion film.

39. The sensor according to claim 35, wherein

the substrate further includes a support substrate and an insulation layer,

the semiconductor substrate, the insulation layer and the support substrate are stacked in this order, and

the semiconductor region is disposed in the semiconductor substrate.

40. The sensor according to claim 39, wherein

the support substrate has a predetermined fixed electric potential.

41. A method for detecting a magnetic field comprising:

supplying a driving current to a magnetic field detection portion, wherein the magnetic field detection portion is disposed in a semiconductor region having a predetermined conductive type, and wherein the semiconductor region is disposed in a substrate; and

detecting a Hall voltage corresponding to the magnetic field, which is in parallel to a surface of the substrate and applied to the magnetic field detection portion, wherein

a pair of first electrodes is disposed on a surface of the semiconductor region,

two pairs of second electrodes are disposed on the surface of the semiconductor region,

one pair of second electrodes sandwiches one of first electrodes, and the other pair of second electrodes sandwiches the other one of first electrodes,

the one pair of second electrodes includes first and second terminals, and the other pair of second electrodes includes third and fourth terminals,

the first and third terminals are disposed on one side of a line connecting between the first electrodes, and the second and fourth terminals are disposed on the other side of the line,

the first and fourth terminals are electrically coupled with a first wiring, and the second and third terminals are electrically coupled with a second wiring,

the magnetic field detection portion, the first electrodes and the second electrodes provide a vertical Hall element,

the driving current is supplied to the magnetic field detection portion through one of the first and second electrodes so that the one of the first and second electrodes provides a driving current supply electrode, and

the Hall voltage is detected through the other one of the first and second electrodes so that the other one of the first and second electrodes provides a Hall voltage detecting electrode,

the method further comprising;

switching the one of the first and second electrodes from the driving current supply electrode to the Hall voltage detecting electrode, and switching the other one of the first and second electrodes from the Hall voltage detecting electrode to the driving current supply electrode.

42. The method according to claim 41, wherein

the driving current is a predetermined constant current.

43. The sensor according to claim 41, wherein

the first and second terminals are arranged in a line symmetrical manner with respect to the line connecting between the first electrodes, and

the third and fourth terminals are arranged in a line symmetrical manner with respect to the line.

44. A method for detecting a magnetic field comprising:

supplying a driving current to a magnetic field detection portion, wherein the magnetic field detection portion is disposed in a semiconductor region having a predetermined conductive type, and wherein the semiconductor region is disposed in a substrate; and

detecting a Hall voltage corresponding to the magnetic field, which is in parallel to a surface of the substrate and applied to the magnetic field detection portion, wherein

a first electrode includes first, second and third pads, which are disposed on a surface of the semiconductor region and aligned on a line connecting between the first and third pads so that the first and third pads sandwich the second pad,

a second electrode includes first to sixth terminals disposed on the surface of the semiconductor region,

the first and second terminals sandwich the first pad, the third and fourth terminals sandwich the second pad, and the fifth and sixth terminals sandwich the third pad,

the first, third and fifth terminals are disposed on one side of a line connecting between the first and third pads, and the second, fourth and sixth terminals are disposed on the other side of the line,

the first, fourth and fifth terminals are electrically coupled with a seventh wiring, and the second, third and sixth terminals are electrically coupled with an eighth wiring,

the magnetic field detection portion, the first electrode and the second electrode provide a vertical Hall element,

the driving current is supplied to the magnetic field detection portion through one of the first and second electrodes so that the one of the first and second electrodes provides a driving current supply electrode, and

the Hall voltage is detected through the other one of the first and second electrodes detects the Hall voltage so that the other one of the first and second electrodes provides a Hall voltage detecting electrode,

the method further comprising;

switching the one of the first and second electrodes from the driving current supply electrode to the Hall voltage detecting electrode, and switching the other one of the first and second electrodes from the Hall voltage detecting electrode to the driving current supply electrode.

45. The method according to claim 44, wherein

the driving current is a predetermined constant current.

46. The sensor according to claim 44, wherein

the first and second terminals are arranged in a line symmetrical manner with respect to the line connecting between the first and third pads,

the third and fourth terminals are arranged in a line symmetrical manner with respect to the line, and

the fifth and sixth terminals are arranged in a line symmetrical manner with respect to the line.