Signal compensation system configured to measure and counteract asymmetry in hall sensors

Abstract

A sensor cross-talk compensation system includes a semiconductor substrate having a first main surface and a second main surface opposite to the first main surface; a vertical Hall sensor element disposed in the semiconductor substrate, the vertical Hall sensor element is configured to generate a sensor signal in response to a magnetic field impinging thereon; and an asymmetry detector configured to detect an asymmetric characteristic of the vertical Hall sensor element. The asymmetry detector includes a detector main region that vertically extends into the semiconductor substrate from the first main surface towards the second main surface and is of a conductivity type having a first doping concentration; and at least three detector contacts disposed in the detector main region at the first main surface, the at least three detector contacts are ohmic contacts of the conductivity type having a second doping concentration that is higher than the first doping concentration.

What is claimed is: 
     
         1 . A method of manufacturing a sensor chip, the method comprising:
 providing a semiconductor substrate and having a first main surface and a second main surface opposite to the first main surface;   forming a sensor main region of a vertical Hall sensor element in the semiconductor substrate, wherein the sensor main region vertically extends into the semiconductor substrate from the first main surface towards the second main surface and is of a first conductivity type, and wherein the vertical Hall sensor element is configured to generate a first sensor signal in response to a first magnetic field impinging thereon from a first direction;   forming a plurality of sensor contacts in the sensor main region, wherein the plurality of sensor contacts are of a second conductivity type;   forming a detector main region of an asymmetry detector in the semiconductor substrate, wherein the detector main region vertically extends into the semiconductor substrate from the first main surface towards the second main surface and is of a third conductivity type having a first doping concentration, wherein the detector main region includes a first peripheral edge and a second peripheral edge oppositely arranged from the first peripheral edge in the first direction, and wherein the asymmetry detector is configured to detect an asymmetric characteristic of the vertical Hall sensor element; and   forming at least three detector contacts in the detector main region, wherein the at least three detector contacts are ohmic contacts of a fourth conductivity type having a second doping concentration that is higher than the first doping concentration, wherein the first conductivity type, the second conductivity type, the third conductivity type, and the fourth conductivity type are a same conductivity type,   wherein a first pair of detector contacts of the at least three detector contacts have a first resistance therebetween,   wherein a second pair of detector contacts of the at least three detector contacts have a second resistance therebetween,   wherein a first detector contact of the first pair of detector contacts is arranged from the first peripheral edge by a first distance,   wherein a first detector contact of the second pair of detector contacts is arranged from the second peripheral edge by a second distance,   wherein the first resistance and the second resistance are equal on a condition that the first distance and the second distance are equal,   wherein the first resistance is greater than the second resistance on a condition that the first distance is less than the second distance, and   wherein the first resistance is less than the second resistance on a condition that the first distance is greater than the second distance.   
     
     
         2 . The method of  claim 1 , wherein:
 forming the sensor main region and forming the detector main region comprises applying a first mask to the first main surface of the semiconductor substrate and forming the sensor main region and the detector main region in a same first doping processing step, and   forming the plurality of sensor contacts and forming the at least three detector contacts comprises applying a second mask to the first main surface of the semiconductor substrate and forming the plurality of sensor contacts and the at least three detector contacts in a same second doping processing step.   
     
     
         3 . The method of  claim 1 , wherein each of the at least three detector contacts have a first elongated shape defining a first longitudinal axis that extends along the first main surface in a second direction orthogonal to the first direction, and wherein the first longitudinal axes of the at least three detector contacts are parallel to each other. 
     
     
         4 . A method of manufacturing a sensor chip, the method comprising:
 providing a semiconductor substrate and having a first main surface and a second main surface opposite to the first main surface;   forming a sensor main region of a vertical Hall sensor element in the semiconductor substrate, wherein the sensor main region vertically extends into the semiconductor substrate from the first main surface towards the second main surface and is of a first conductivity type, and wherein the vertical Hall sensor element is configured to generate a first sensor signal in response to a first magnetic field impinging thereon from a first direction;   forming a plurality of sensor contacts in the sensor main region, wherein the plurality of sensor contacts are of a second conductivity type; and   forming a detector main region of an asymmetry detector in the semiconductor substrate, wherein the detector main region vertically extends into the semiconductor substrate from the first main surface towards the second main surface and is of a third conductivity type having a first doping concentration, wherein the detector main region includes a first peripheral edge and a second peripheral edge oppositely arranged from the first peripheral edge in the first direction, and wherein the asymmetry detector is configured to detect an asymmetric characteristic of the vertical Hall sensor element,   wherein the first conductivity type, the second conductivity type, and the third conductivity type are a same conductivity type.   
     
     
         5 . The method of  claim 4 , further comprising: forming at least three detector contacts in the detector main region, wherein the at least three detector contacts are ohmic contacts of a fourth conductivity type having a second doping concentration that is higher than the first doping concentration,
 wherein the fourth conductivity type is the same conductivity type as the first conductivity type, the second conductivity type, and the third conductivity type.   
     
     
         6 . The method of  claim 5 , wherein a first pair of detector contacts of the at least three detector contacts have a first resistance therebetween, and
 wherein a second pair of detector contacts of the at least three detector contacts have a second resistance therebetween.   
     
     
         7 . The method of  claim 6 , wherein a first detector contact of the first pair of detector contacts is arranged from the first peripheral edge by a first distance, and
 wherein a first detector contact of the second pair of detector contacts is arranged from the second peripheral edge by a second distance.   
     
     
         8 . The method of  claim 7 , wherein the first resistance and the second resistance are equal on a condition that the first distance and the second distance are equal,
 wherein the first resistance is greater than the second resistance on a condition that the first distance is less than the second distance, and   wherein the first resistance is less than the second resistance on a condition that the first distance is greater than the second distance.   
     
     
         9 . The method of  claim 8 , wherein:
 forming the sensor main region and forming the detector main region comprises applying a first mask to the first main surface of the semiconductor substrate and forming the sensor main region and the detector main region in a same first doping processing step.   
     
     
         10 . The method of  claim 9 , wherein:
 forming the plurality of sensor contacts and forming the at least three detector contacts comprises applying a second mask to the first main surface of the semiconductor substrate and forming the plurality of sensor contacts and the at least three detector contacts in a same second doping processing step.   
     
     
         11 . The method of  claim 4 , wherein:
 forming the sensor main region and forming the detector main region comprises applying a first mask to the first main surface of the semiconductor substrate and forming the sensor main region and the detector main region in a same first doping processing step.   
     
     
         12 . The method of  claim 11 , further comprising:
 forming at least three detector contacts in the detector main region, wherein the at least three detector contacts are ohmic contacts of a fourth conductivity type having a second doping concentration that is higher than the first doping concentration,   wherein the fourth conductivity type is the same conductivity type as the first conductivity type, the second conductivity type, and the third conductivity type, and   wherein forming the plurality of sensor contacts and forming the at least three detector contacts comprises applying a second mask to the first main surface of the semiconductor substrate and forming the plurality of sensor contacts and the at least three detector contacts in a same second doping processing step.   
     
     
         13 . The method of  claim 4 , wherein each of the at least three detector contacts have a first elongated shape defining a first longitudinal axis that extends along the first main surface in a second direction orthogonal to the first direction, and wherein the first longitudinal axes of the at least three detector contacts are parallel to each other. 
     
     
         14 . The method of  claim 5 , wherein:
 forming the plurality of sensor contacts and forming the at least three detector contacts comprises applying a mask to the first main surface of the semiconductor substrate and forming the plurality of sensor contacts and the at least three detector contacts in a same second doping processing step.   
     
     
         15 . A method of manufacturing a sensor chip, the method comprising:
 providing a semiconductor substrate and having a first main surface and a second main surface opposite to the first main surface;   forming a sensor main region of a vertical Hall sensor element in the semiconductor substrate, wherein the sensor main region vertically extends into the semiconductor substrate from the first main surface towards the second main surface and is of a first conductivity type, and wherein the vertical Hall sensor element is configured to generate a first sensor signal in response to a first magnetic field impinging thereon from a first direction;   forming a plurality of sensor contacts in the sensor main region, wherein the plurality of sensor contacts are of a second conductivity type;   forming a detector main region of an asymmetry detector in the semiconductor substrate, wherein the detector main region vertically extends into the semiconductor substrate from the first main surface towards the second main surface and is of a third conductivity type having a first doping concentration, and wherein the asymmetry detector is configured to detect an asymmetric characteristic of the vertical Hall sensor element; and   forming at least three detector contacts in the detector main region, wherein the at least three detector contacts are ohmic contacts of a fourth conductivity type having a second doping concentration that is higher than the first doping concentration,   wherein the third conductivity type and the fourth conductivity type are a same conductivity type.   
     
     
         16 . The method of  claim 15 , wherein:
 the detector main region includes a first peripheral edge and a second peripheral edge oppositely arranged from the first peripheral edge in the first direction,   a first pair of detector contacts of the at least three detector contacts have a first resistance therebetween,   a second pair of detector contacts of the at least three detector contacts have a second resistance therebetween,   a first detector contact of the first pair of detector contacts is arranged from the first peripheral edge by a first distance, and   a first detector contact of the second pair of detector contacts is arranged from the second peripheral edge by a second distance.   
     
     
         17 . The method of  claim 16 , wherein the first resistance and the second resistance are equal on a condition that the first distance and the second distance are equal, the first resistance is greater than the second resistance on a condition that the first distance is less than the second distance, and the first resistance is less than the second resistance on a condition that the first distance is greater than the second distance. 
     
     
         18 . The method of  claim 15 , wherein forming the sensor main region and forming the detector main region includes applying a first mask to the first main surface of the semiconductor substrate and forming the sensor main region and the detector main region in a same first doping processing step such that the sensor main region and the detector main region have a first identical doping concentration profile. 
     
     
         19 . The method of  claim 15 , wherein forming the plurality of sensor contacts and forming the at least three detector contacts includes applying a second mask to the first main surface of the semiconductor substrate and forming the plurality of sensor contacts and the at least three detector contacts in a same second doping processing step such that the plurality of sensor contacts and the at least three detector contacts have a second identical doping concentration profile. 
     
     
         20 . The method of  claim 15 , wherein the first conductivity type, the second conductivity type, the third conductivity type, and the fourth conductivity type are the same conductivity type.