BG65345B1 - Trimmer vector hall sensor - Google Patents

Abstract

The trimmer Hall sensor is used in the field of instrumentation engineering, weak polar magnetometry and microsystems, in contactless automation, instrumentation construction, the power industry, the electrical industry, in military warfare industry, and others. It eliminates basic deficiencies of the analogous solutions û high offset values in the individual output channels and the essential temperature drifting. The sensor comprises semiconductor wafer (1) of mixed type conductivity, on one of the sides of which two pairs of identical rectangular ohmic contacts are made at equal distances, fitted parallel to their long sides. Contacts of one of the pairs are sectioned into two equal parts (2, 3 and 4, 5), parts (4 and 5) of one of the sectioned contacts are fitted between the non-sectioned rectangular ohmic contacts (6 and 7). On the short sides of contacts (6 and 7), at equal distances from them, one pair each of Hall contacts (8, 9 and 10, 11) are formed. Parts (2, 3 and 4, 5) of the sectioned contacts are connected to the end outputs of two trimmer (12 and 13), the middle outputs of which are connected across load resistors (14 and 15), respectively, to the two outputs of a current source (16). Each of contacts (6 and 7) across two loads resistors (17, 18 and 19, 20) connected in series, respectively, is connected to both outputs of the current source (16). The two equal parts (2, 3, and 4, 5) of each of sectioned ohmic contacts are coupled to the respective input (21 and 22) of the first amplifying unit (23), the output of which is output (24) of the component of the magnetic field (33), orthogonal to the surface of wafer (1). The pair of Hall contacts (8, 9 and 10, 11), fitted on the short sides of the two contacts (6 and 7) are connected to the appropriate input (25 and 26) of a second amplifying unit (27), the output of which is output (28) for one of the parallel to the surface of wafer (1) component of magnetic field (33). The middle output of each of the two trimmers (12 and 13) and the common point of each resistor (17, 18 and 19, 20) connected in series are connected to the appropriate input (29 and 30) of a third amplifying unit (31), the output of which is output (32) for the other component of the magnetic field (33), parallel to the surface of wafer (1). The external magnetic field (33) has an arbitrary direction across the semiconductor wafer (1).

Description

The invention relates to a three-dimensional Hall vector sensor, applicable in the field of measurement technology, low-field magnetometry, sensor and microsystems, contactless automation, instrumentation, energy, electrical engineering, military, and others.

BACKGROUND OF THE INVENTION

A three-dimensional Hall vector sensor is known, comprising a semiconductor conductor with impurity-type impedance, three equal rectangular ohmic contacts formed on one side of each other, one central and two extreme, parallel to its long sides. One Hall contact is formed on the short sides of the central rectangular ohmic contact and at equal distances from it. In the rectangular regions between the central and the two extreme ohmic contacts, laterally and at equal distances from them, there is another Hall contact, which are connected two by two transversely. The central ohmic contact through the power source and the corresponding load resistor is connected to the two end rectangular contacts. The output for one parallel to the surface of the substrate component of the magnetic field are the two Hall contacts located on the short sides of the central rectangular contact, the output secondarily parallel to the surface of the substrate component of the magnetic field are the two extreme ohmic contacts, and the output for the orthogonal the substrate component of the magnetic field vector are the cross-linked other Hall contacts. The external magnetic field is in any direction relative to the semiconductor substrate [1].

The disadvantages of this three-dimensional Hall vector sensor are the high values of the offset (parasitic residual signals at the three sensor outputs in the absence of a magnetic field) as a result of inevitable defects, inhomogeneities and mechanical stresses in the crystal structure of the semiconductor geometry, disturbed geometry the corresponding output contacts, etc. as well as the significant temperature drift of the offsets of the three outputs over a wide delta range, due to the different effect of temperature T on the three sensor channels, resulting from the above-mentioned inevitable defects and inhomogeneities.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a three-dimensional Hall vector sensor with low output offset values and a strong reduction in their temperature drift over a wide temperature range.

This problem is solved with a three-dimensional Hall vector sensor containing a semiconductor substrate with impurity-type impedance, on one side of which are formed equal distances from each other by two pairs of identical rectangular ohmic contacts located parallel to their long sides. The contacts of one pair are split into two equal parts, with the parts of one of the sectioned contacts arranged between the non-sectioned ohmic contacts. One pair of Hall contacts are formed on the short sides of the intact rectangular contacts and at equal distances from them. The parts of each of the sectioned contacts are connected respectively to the terminal terminals of two trimmers, the average terminals of which are connected through the load resistors respectively to the two terminals of a current source. Each of the non-sectioned ohmic contacts, respectively, through two consecutively connected load resistors, is connected to the two terminals of the current source. The two equal parts of each of the sectioned ohmic contacts are connected to a corresponding input of a first amplifier block, the output of which is an output of the magnetic field component orthogonal to the substrate surface. The pairs of Hall contacts located on the short sides of the non-sectioned ohmic contacts are connected to a corresponding input of a second amplifier block, the output of which is an output for one component of the magnetic field parallel to the surface of the substrate. The average terminal of each of the two trimmers

65345 Bl and the common point of each of the load resistors in series are connected to a corresponding input of a third amplifier block, the output of which is an output to the other component of the magnetic field parallel to the surface of the substrate. The external magnetic field is in any direction relative to the semiconductor substrate.

Advantages of the invention are the low values of the residual offsets at the three outputs and their greatly reduced temperature drifts as a result of circuit processing and subtraction of the initial offsets with almost the same value and sign from the double output channels formed on the semiconductor substrate for each of the three orthogonals components of the magnetic vector.

Description of the attached figures

The invention is explained in more detail by an exemplary embodiment given in the accompanying figure.

Examples of carrying out the invention

Hall's three-dimensional vector sensor comprises a semiconductor substrate 1 with impurity conductance type, on one side of which two pairs of identical rectangular ohmic contacts, parallel to their long sides, are formed at equal distances from one another. The contacts of one pair are divided into two equal parts 2 and 3, and 4 and 5, and the parts 4 and 5 of one of the sectioned contacts are located between the non-sectioned ohmic contacts 6 and 7. On the short sides of the non-sectioned rectangular contacts 6 and 7 , and equal pairs of Hall contacts 8 and 9 and 10 and 11 are formed at equal distances from them. Parts 2 and 3, and 4 and 5 of each sectioned contacts are connected respectively to the end terminals of two trimmers 12 and 13, the middle terminals to which are connected through load resistors 14 and 15 respectively to the two terminals a to source 16. Each of the non-sectioned ohmic contacts 6 and 7 respectively through two consecutively connected load resistors 17 and 18 and 19 and 20 is connected to the two terminals of the source 16. The two equal parts 2 and 3, and 4 and 5 are partitioned ohmic contacts with corresponding input 21 and 22 of the first amplifier unit 23, the output of which is an output 24 for the orthogonal component of the magnetic field 33 orthogonal to the substrate. Couples Hall contacts 8, 9, and 10, 11, located on the short sides of the non-sectioned ohms contacts 6 and 7 are related to respectively, an input 25 and 26 of a second amplifier unit 27, the output of which is an output 28 for one parallel to the surface of the substrate 1 of the magnetic field component 33. The average terminal of each of the two trimmers 12 and 13 and the common point of each of the series connected load resistors 17 and 18, and 19 and 20 are connected to a corresponding input 29 and 30 of a third amplifier block 31, the output of which is an output 32 for the other component of the magnetic field parallel to the surface 1 of the magnetic field 33. The external magnetic field 33 is arbitrary direction toward the semiconductor floor ka 1.

The action of the three-dimensional Hall vector sensor according to the invention is as follows.

When the source 16 is switched on, respectively, through the ohmic contacts 6 and 2-3, and 4-5 and 7, two opposite currents 1 _{6 2 3} and - 1 _{4 5 7} flow. By selecting the resistors in the bridge circuits formed by trimmers 12 and 13 and resistors 14,15,17,18,19 and 20, the values of these two current components are equalized I ₃ = | -1 _{4 5 7} | Also, the current components through the respective sectioned contacts 2 and 3 and 4 and 5 are equal to each other. Due to the equipotentiality of the supply ohmic contacts 2, 3, 6, 4, 5 and 7 in the absence of a magnetic field B 33, initially the current trajectories 1 ₆ and 1 _{4 5 7} are perpendicular to the upper surface of the semiconductor substrate 1 containing all ohmic contacts 2 , 3, 6, 8, 9, 4, 5, 7, 10 and 11. They penetrate deeply into the volume, and in the regions between contacts 6 and 2-3, and 4-5 and 7, they are parallel to the surface of the pad 1. The instrument structure and bridge circuitry thus realized make it possible to achieve electrical symmetry in the left and right portions of the the three-dimensional Hall vector sensor determined by contacts 6-8-9-2-3 and 4-5-7-10-11. The application of an external magnetic field B 33 in any direction to the semiconductor substrate 1 through its three orthogonal components B _x , B _y and B _z generates on the corresponding

65345 Bl pairs of output channels (for Β _χ : cold contacts 8 and 9 and 10 and 11; for B _y : the mean terminal of trimmer 12 and the common point of the two resistors 19 and 20, respectively, the mean terminal of trimmer 13 and the common point of resistors 17 and 18; for B _z : pairs of sectioned ohmic contacts 2 and 3, respectively 4 and 5) information signals for the three orthogonal magnetic components. The origin of these signals is the Hall effect. The magnetic field Β _χ exerts a deflection effect by the Lorentz force on the velocity component of the velocity carriers perpendicular to the surface of the substrate 1. As a result, in the regions on the two short sides of the rectangular non-sectioned contacts 6 and 7, respectively, two Hall voltages with opposite polarity are generated, exactly where the pairs of ohmic contacts 8 and 9 and 10 and 11 respectively are located, i. V ₈₉ (B _x ) = | -V _{10 n} (B _x ) |. Different signs of The navigation signals are due to the opposing directions of the currents through the ohmic contacts 6 and 7. The magnetic field in the _y following the same sensor mechanism and the Lorentz force generated by two opposite sign voltages of the Hall respectively between contacts 6 and 4-5, and between 2-3 and 7, i. V _{64 5} (V _y ) = | -V _{2 3 7} (V _y ) |. These two Hall signals are, however, recorded between the common point of the two series-connected load resistors 17 and 18 and the middle terminal of the trimmer 13, and between the average terminal of the trimmer 12 and the common point of connection of the two load resistors 19 and 20. the method of measuring the magnetic component B _y by means of resistor bridges provides symmetry and potential equilibrium at the output points of the two B _y sensor channels, even though they are made of sectioned 2 and 3, 4 and 5, and non-sectioned 6 and 7 ohmic contacts . The magnetic field B _z exerts a lateral (lateral) deflecting effect on the velocity component of the carrier velocity parallel to the surface of the substrate 1 by the Lorentz force. Due to the opposite directions of current components parallel to the surface I ,,, and -1., In magnetic field B, the currents through contacts 2 and 5 simultaneously increase (decrease) and through contacts 3 and 4 simultaneously decrease (increase). The trimmers 12 and 13 are set to be equal in value to the opposite Hall voltage V _{2 3} (B _z ) = I - V _{10 (} , (B _z ) I of the B _d- sensor channels. Therefore, the innovativeness of the technical solution is that the corresponding pairs of output differential channels of a given magnetic component are so formed that their running signals are equal in value and have the opposite sign. At the same time, the respective pairs of channels have a common transducer zone, which determines their identical and opposite in magnitude, and almost the same Another feature is that the offsets for a given pair of output channels are of the same sign. (the subtracted signals are the opposite sign) The residual offset will be drastically reduced at the same time, since the individual Hall channels of the three-dimensional vector sensor are functionally integrated in the same semiconductor conversion region The substrate 1, the inevitable drifts of the individual offset signals of the B _x , B _y and B _z channels are perfectly matched and aligned over a wide delta temperature range. The processing and subtraction of the output voltages for a vector channel is carried out by a corresponding amplifier unit 23, 27 or 31 containing suitable differential amplifiers for this purpose. As a result, the information signals 24, 28 and 32 for the three vector components B _x , B _y, and B _z have substantially minimized offset and greatly reduced temperature drift. The absolute value of the magnetic vector B 33 is determined by the well-known expression | In | = B ² x + B ² y + B ² _z , the values of the three magnetic components being obtained by calibrating the outputs 24, 28 and 32.

The experiments performed with samples of Hall's three-dimensional vector sensor, based on standard silicon integrated technology according to the invention, show that the reduction of both the residual offset and its temperature drift at all three outputs 24,28 and 32 is more than two orders of magnitude ( about 150 times) over a wide temperature range - 20 <T <80 ° C. Therefore, the metrological capabilities of the new vector sensor have been dramatically improved, especially for low-field mag5 purposes.

65345 Bl nitrometry. This unexpected positive effect of Hall's three-dimensional vector converter stems from the original instrument cluster containing two physical channels for each magnetic component. The pair of channels for a vector component generate equal in value but with the opposite sign of Hall voltages. At the same time, the corresponding offsets have almost the same value and have the same sign. If necessary, the magnetic sensitivity of the sensor channels may be increased if a deep p-type ring surrounding all ohmic contacts is formed on the n-conductivity substrate, or if the active sensor zone is restricted by micromachining or other similar approach of silicon integrated technology. The three-dimensional magnetometer can be produced commercially by various modifications to the silicon integrated technology, including CMOS processes. The three-dimensional vector magnetometer and electronic signal processing units can be implemented on a common integrated circuit, forming a 3-D vector microsystem for a magnetic field.

Claims (1)

Claims 1. A three-dimensional Hall vector sensor comprising a semiconductor conductor with impurity type impedance, on one side of which are formed four equal rectangular ohmic contacts, parallel to their long sides, on the short sides of two of the rectangular ohmic ones contacts and at equal distances from it are formed by one Hall contact, a current source, and the external magnetic field is in any direction relative to the semiconductor substrate, characterized in that the rectangular ohmic contacts are united in two pairs, in one pair they are divided into two equal parts (2 and 3) and (4 and 5), and the parts (4 and 5) of one of the sectioned contacts are located between the non-sectioned ohmic contacts ( 6 and 7), the running contacts (8 and 9) and respectively (10 and 11) are located at the non-sectioned rectangular contacts (6 and 7), the parts (2 and 3), and (4 and 5) of the sectioned contacts are connected respectively with the terminal terminals of two trimmers (12 and 13), the average terminals of which are connected through load resistors (14 and 15) respectively to the two terminals of the power source (16), each of the non-sectioned ohmic contacts (6 and 7) respectively through two load resistors (17 and 18) respectively, and (19 and 20) connected to the two terminals of the power source (16) and the two equal parts (2 and 3) , and (4 and 5) of each of the sectioned ohmic contacts are connected to a corresponding input (21 and 22) of a first amplifier block (23), the output of which is an output (24) for the component orthogonal to the surface of the substrate (1). the magnetic field (33), such as the Hall contacts (8 and 9) and (10 and 11), located on the short sides of the two non-sectioned ohmic contacts (6 and 7) are connected to a corresponding input (25 and 26) of a second amplifier block (27), the output of which is an output (28) for one parallel to the surface of the substrate (1) of the magnetic field component (33), and the middle terminal of each of the two trimmers (12 and 13) and the common point of each of the series load resistors (17 and 18) and (19 and 20) are connected to the respective input (29 and 30) of the third amplifier block (31), the output of which is the output (32) of the other component of the magnetic field (33) parallel to the surface of the substrate (1).