Low offset and high sensitivity vertical hall effect sensor

Patent metadata

Field	Value
Publication number	US-9252355-B2
Application number	US-201414478317-A
Country	US
Kind code	B2
Filing date	Sep 5, 2014
Priority date	Sep 6, 2013
Publication date	Feb 2, 2016
Grant date	Feb 2, 2016

Abstract

A vertical Hall Effect sensor is provided having a high degree of symmetry between its bias modes, can be adapted to exhibit a small pre-spinning systematic offset, and complies with the minimal spacing requirements allowed by the manufacturing technology (e.g., CMOS) between the inner contacts. These characteristics enable the vertical Hall Effect sensor to have optimal performance with regard to offset and sensitivity.

First claim

What is claimed is:

1. A vertical Hall Effect sensor comprising:
a Hall Effect device including:
a substrate having a top surface and a region below the top surface of a first conductivity type;
a conductive well embedded in the region and having a second conductivity type;
a first, second, third, fourth, fifth, sixth, seventh, and eighth ohmic contact arranged sequentially and spaced apart from each other in a row within the conductive well, the row being generally parallel to the top surface, each of the first, second, third, fourth, fifth, sixth, seventh, and eight ohmic contacts having a conductivity that is different than the conductivity of the well;
a voltage measuring device including four input terminals;
a switching device configured to be connected to a bias source and including:
four output terminals which are electrically connected to the four input terminals, respectively, of the switching device; and
a first, second, third, fourth, fifth, and sixth input terminal;
wherein the first and the sixth ohmic contacts are electrically connected to each other and to the fifth input terminal of the switching device,
wherein the third and the eighth ohmic contacts are electrically connected to each other and to the second input terminal of the switching device, wherein the second ohmic contact is electrically connected to the first input terminal of the switching device, wherein the fourth ohmic contact is electrically connected to the third input terminal of the switching device, wherein the fifth ohmic contact is electrically connected to the fourth input terminal of the switching device, wherein the seventh ohmic contact is electrically connected to the sixth input terminal of the switching device, wherein the switching device includes a plurality of modes of operation, and
wherein in each of the modes of operation, the switching device is configured to electrically connect two of the input terminals selected from the first, second, third, fourth, fifth, and sixth input terminals of the switching device to the bias source and to ground, respectively, and to electrically connect the remaining four input terminals of the switching device not connected to the bias source and to ground to the four input terminals of the voltage measuring device via the four output terminals, respectively, of the switching device.

2. The vertical Hall Effect sensor of claim 1 , wherein the switching device includes a mode of operation in which the two input terminals electrically connected to the bias source and to ground, respectively, comprises an alternating pair of input terminals selected from the second, third, fourth, and fifth input terminals of the switching device, and
the remaining four input terminals connected to the four output terminals of the switching device include the first and sixth input terminals and the remaining two input terminals of the second, third, fourth, and fifth input terminals not connected to the bias source or to ground.

3. The vertical Hall effect sensor of claim 1 , wherein the first ohmic contact is spaced apart from the second ohmic contact and the eighth ohmic contact is spaced apart from the seventh ohmic contact by a first distance,
wherein the second ohmic contact is spaced apart from the third ohmic contact, the third ohmic contact is spaced apart from the fourth ohmic contact, the fourth ohmic contact is spaced apart from the fifth ohmic contact, the fifth ohmic contact is spaced apart from the sixth ohmic contact, and the sixth ohmic contact is spaced apart from the seventh ohmic contact by a second distance, and
wherein the first distance is greater than the second distance.

4. The vertical Hall Effect sensor of claim 3 , wherein the second distance is approximately half the first distance.

5. The vertical Hall Effect sensor of claim 3 , wherein the conductive well comprises an N-type conductivity and the region comprises a P-type conductivity.

6. The vertical Hall Effect sensor of claim 5 , wherein the first, second, third, fourth, fifth, sixth, seventh, and eighth ohmic contacts comprise a more highly doped N-type conductivity than the N-type conductivity of the conductive well.

7. The vertical Hall Effect sensor of claim 1 , wherein the first and the sixth ohmic contacts and the third and the eighth ohmic contacts are electrically connected via metallizations.

8. The vertical Hall Effect sensor of claim 3 , wherein the voltage measuring device is configured to process a voltage received across the four input terminals of the voltage measuring device to determine Hall voltage that corresponds to a measurement of a magnetic field.

9. A Hall Effect device comprising:
a substrate having a top surface and a region below the top surface of a first conductivity type;
a conductive well embedded in the region and having a second conductivity type;
a first, second, third, fourth, fifth, sixth, seventh, and eighth ohmic contact arranged sequentially and spaced apart from each other in a row within the conductive well, the row being generally parallel to the top surface, each of the first, second, third, fourth, fifth, sixth, seventh, and eight ohmic contacts having a conductivity that is different than the conductivity of the well;
wherein the first and the sixth ohmic contacts are electrically connected to each other and the third and the eighth ohmic contacts are electrically connected to each other.

10. The Hall Effect device of claim 9 , wherein the first ohmic contact is spaced apart from the second ohmic contact and the eighth ohmic contact is spaced apart from the seventh ohmic contact by a first distance,
wherein the second ohmic contact is spaced apart from the third ohmic contact, the third ohmic contact is spaced apart from the fourth ohmic contact, the fourth ohmic contact is spaced apart from the fifth ohmic contact, the fifth ohmic contact is spaced apart from the sixth ohmic contact, and the sixth ohmic contact is spaced apart from the seventh ohmic contact by a second distance, and
wherein the first distance is greater than the second distance.

11. The Hall Effect device of claim 10 , wherein the second distance is approximately half the first distance.

12. The Hall Effect device of claim 10 , wherein the conductive well comprises an N-type conductivity and the region comprises a P-type conductivity.

13. The vertical Hall Effect device of claim 12 , wherein the first, second, third, fourth, fifth, sixth, seventh, and eighth ohmic contacts comprise a more highly doped N-type conductivity than the N-type conductivity of the conductive well.

14. The vertical Hall Effect sensor of claim 9 , wherein the first and the sixth ohmic contacts and the third and the eighth ohmic contacts are electrically connected via metallizations.

15. A method of fabricating a Hall Effect device, the method comprising:
forming a first, second, third, fourth, fifth, sixth, seventh, and eighth ohmic contact sequentially and spaced apart from each other in a row within a conductive well in a region of a substrate, the conductive well being of a first conductivity type and the region being of a second conductivity type, the row being generally parallel to an upper surface of the substrate, each of the first, second, third, fourth, fifth, sixth, seventh, and
eight ohmic contacts having a conductivity that is different than the conductivity of the well; and
electrically connecting the first and the sixth ohmic contacts to each other and the third and the eighth contacts to each other, wherein the first ohmic contact is spaced apart from the second ohmic contact and the eighth ohmic contact

Assignees

• Bosch Gmbh Robert

Inventors

• Vanderhaegen Johan
• Ezekwe Chinwuba
• Xing Xinyu

Classifications

• G01R33/075

  Hall devices configured for spinning current measurements · CPC title

• G01R33/077 Primary

  Vertical Hall-effect devices · CPC title

• 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

• H01L43/065 Primary

  Electricity · mapped topic

• H10N52/101 Primary

  Semiconductor Hall-effect devices · CPC title