BG111199A - Two-dimensional magnetometer - Google Patents

Abstract

The two-dimensional magnetometer, contains a solid-state n-type pad on one side of which have formed two square ohm contacts (2) and (3), located close to one another. Symmetrically in relation to the four countries has consistently clockwise in a rectangular ohm contact-first (4) and (5), second (6) and (7), third (8) and (9), and fourth (10) and (11), all with the same dimensions. Each of the two groups, containing a square (2) and (3) and four rectangular socket (4) and (5), (6) and (7) and respectively (8) and (9), (10) and (11) is surrounded with deep p-type ring (12). Contacts (2) and (3) are joined with current supply (13). The first (4) and (5) and the second (6) and (7) contacts from each group, respectively, are related to each other. Fourth (10) and (11) and respectively third (8) and (9) contacts from each group are the exits (14) and (15) of the two-dimensional magnetometer for the two orthogonal components of the magnetic field (16), lying in the plane of the n-type pad (1).

Description

The invention relates to a two-dimensional magnetometer applicable in the field of sensor, micro and nano-technologies, systems engineering including bioengineering, robotics and mechatronics, contactless measurement of angular and linear displacements, biomedical research, energy and energy objects, automation, positioning , control technology and low-field magnetometry, military and security, and more.

BACKGROUND OF THE INVENTION

A two-dimensional magnetometer containing an i-type semiconductor substrate is known on one side of which a central ohmic support is formed on one side of the substrate. ♦ · · · · · ♦ ♦ ♦ · ♦ ♦ ♦ ♦ ♦ There is a rectangular internal ohmic contact and an external ohmic contact in series, with distances and symmetrically with respect to its four sides. . The four external contacts are connected and connected to the central contact via a power source. The measured external magnetic field lies in the plane of the n-type substrate, with each pair of opposite internal contacts relative to the central one being the outputs of the two-dimensional magnetometer for the two orthogonal plane components of the magnetic field vector, [1,2].

The disadvantage of this two-dimensional magnetometer is the reduced accuracy of the individual sensor channels when measuring the plane components of the magnetic field as a result of the parasitic interchannel influence of the surface flow of the four supply currents between the central and four terminal contacts.

TECHNICAL NATURE

It is an object of the invention to provide a two-dimensional magnetometer with high measurement accuracy of the two sensor channels.

This problem is solved by a two-dimensional magnetometer containing an i-type semiconductor support, on which one side is formed adjacent to each other two square-shaped ohmic contacts with distances and symmetrically with respect to the four sides of each of them. clockwise one rectangular ohmic contact - first, second, third and fourth, all the same size. Each of the two groups containing square and four rectangular contacts is surrounded by a deep p-type ring. The two square contacts are connected to a power source. The first and second contacts of each group are linked. The fourth and third contacts of each group, respectively, are the outputs of the two-dimensional magnetometer for the two orthogonal components of the magnetic field lying in the plane of the i-pad.

An advantage of the invention is the high measurement accuracy of the two sensor channels due to the greatly reduced surface flow of the supply current achieved by the p-ring surrounding the two contact groups.

An advantage is also the increased magnetosensitivity of the two sensor channels as a result of the sequential connection of the outputs of the two transducers formed by the two groups of ohmic contacts and the presence of the deep p-ring surrounding them.

Another advantage is the increased signal-to-noise ratio and resolution of the measured magnetic induction from the increased sensitivity of the sensor channels.

DESCRIPTION OF THE FIGURES Attached

The invention is explained in more detail by an exemplary embodiment given in the annexed Figure 1.

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EXAMPLES FOR IMPLEMENTATION

The two-dimensional magnetometer contains a n-type semiconductor support 1, on which one square-shaped ohmic contacts 2 and 3 are formed on one side of each other and are spaced symmetrically with respect to the four sides of each of them. arrow on one rectangular ohmic contact - first 4 and 5, second 6 and 7, third 8 and 9 and fourth 10 and 11, all of the same size. Each of the two groups containing square 2 and 3 and four rectangular contacts 4 and 5, 6 and 7, respectively 8 and 9, 10 and 11 is surrounded by a deep £> -type ring 12. The two square contacts 2 and 3 are connected 13. The first 4 and 5 and respectively the second 6 and 7 contacts of each group are interconnected. The fourth 10 and 11 and respectively the third 8 and 9 contacts of each group are the outputs 14 and 15 of the two-dimensional magnetometer for the two orthogonal components of the magnetic field 16 lying in the plane of the i-type support 1.

The action of the two-dimensional magnetometer according to the invention is as follows.

When the two square contacts 2 and 3 are connected to the source 13, a supply current / ₂ flows between them. Its trajectory in the areas under contacts 2 and 3 is initially perpendicular to the upper surface of the substrate 1, since the square low-ohmic contacts 2 and 3 represent equipotential planes. The other part of the effective current path / ₂ , h is in the volume of the n-pad 1 and is parallel to its upper side. An important feature is that the directions of current / _{2; 3} below the square contacts 2 and 3 are opposite, Z ₂ = | - 7 ₃ | = / ₂ , h- The deep p-type ring surrounding sufficiently close ohmic contacts 2, 3, 4, 5, 6, 7, 8, 9, 10 and 11 drastically reduces the drainage on the surface of the substrate 1 of the supply current / _{2 3} .

The external magnetic field B 16, which is of arbitrary orientation in the plane of the substrate 1, through its two mutually perpendicular components B _x and B _y, gives rise to corresponding laterally deflecting current carriers / _{2 3} Lorentz forces, F _L = gK _dr x B, where q is the elemental load of the electron, and K _dr is the vector of the average drift velocity of the carriers in our electrons. As a result of this Lorentzian deflection, in the surface zones where ohmic contacts 4 and 8 and 6 and 10 respectively of one group and 5 and 9 and 7 and 11 respectively of the other are located, opposite sign electric loads are generated. This leads to the appearance of Hall stresses on these contacts as follows: and RbdoC-Vu), and respectively K ₅₉ (B _X ) and K _7> μ (B _y ). Due to the structural symmetry of the two groups of contacts and the opposite direction of current Z _{2> 3} under contacts 2 and 3, these voltages are uniform in value and have opposite polarity, K _{4> 8} (B _X ) = | - Γ5,9 <Α ) Ι and K _{6> s} (5y) ⁼ | - K _7> µ (Lou) | When the two first 4 and 5 and the two second 6 and 7 contacts of each group are connected respectively to each other, the Hall stresses are summed up: ₉ (V _X ) = K _{4 8} (V _X ) + V _{5 9} (V _X ) and K _{6> 11} (^) = K _{6, 1o} (R _S) + R _{7> 11} (B _S). Therefore, double-Hall Hall voltages are generated at the differential outputs of Kudi (B _y ) 14 and K _{8 9} (B _X ) 15 of the biaxial vector magnetometer than if only one ft ft were used.

· · · · · · · Ft ft • * ft · · · ft ft • · ft ft ft ···· ft ft ft • · ft ft ft ft · · · · · · · ft · · · · · · · configured by one group of ohmic contacts, for example 2, 4, 6, 8 and 10. The two output Hall signals 14 and 15 are linear and odd functions of the values and directions of the components B _x and B _y of field B 16, and therefore guarantee high metrological quality of 2-D sensors. The absolute value of the vector of the magnetic field B 16 in the x-y plane of the substrate 1 and the angle поле of the field B 16 with respect to a fixed reference axis in 2 2 1/2 1 the same plane are given by the expressions: | B | = (B _x + B _Y Y ^£ and Θ = tan \ V _y (B _y ) IV _x (B _x )).

The unexpected beneficial effect of the new technical solution lies in the possibility of using the same power supply current / ₂ h via two simplified configurations ohmic contacts to generate two by two linear and odd of Hall voltages, registering the components of the flat magnetic vector B _(x , In _B ). After summing the output signals without additional circuitry, the magnetic sensitivity of the two outputs 14 and 15 is practically doubled. It is essential to simplify the post-processing of the output voltages 14 and 15 that the selected symmetrical structure determines the equality of the magnetic sensitivities of outputs 14 and 15. The surface geometry of the parasitic currents is drastically minimized by the specific geometry of the? Their flow to the surface has been virtually eliminated and the measurement accuracy of the two sensor channels has been significantly improved. The deep / 2-ring 12 also improves the orthogonality of the currents 7 ₂ and 7 ₃ through the two square power contacts 2 and 3 in the absence of a magnetic field B 16 with respect to the upper plane of the substrate 1. Thus, the current lines 7 ₂₃ penetrate deeply into the volume of the semiconductor substrate 1. Therefore, the influence of the two components B _x and B _y of the magnetic field B 16 by the Lorentz forces F _L on currents 1 ₂ and 7 ₃ is significantly increased, and the magnetic sensitivity of the two channels also.

The experiments performed with prototypes of the new two-dimensional magnetometer, based on the silicon bipolar technology according to the invention, and comparing the results with those of the known solution show that at a fixed value of the supply current / ₂ , h ⁼ const and a certain direction of the magnetic field 1? 16 in the plane of the n-Si substrate 1, the magnetic sensitivities of the two x- and y-sensor channels 14 and 15 are equal and twice as large. One of the most important sensory parameters of the x- and y-channels, the signal / noise ratio S / N, has also been improved. It has been found that the parasitic influence between the two sensor channels is substantially minimized and the measurement accuracy of the two-dimensional magnetometer is significantly increased. If necessary, the 2-D magnetometer can be implemented with micromachining silicon technology.

APPENDIX: one figure ♦ is · • ·

REFERENCES [1] Ch.S. Roumenin, Magnetic vector sensor based on Hall effect, Compt. Rendus de 1 'Acad. Bulg. Sci., 42 (4) (1989) 59-62.

[2] M. Paranjape, L. Landsberger, M. Kahrizi, A 2-D vertical Hall magnetic field sensor using active carrier confinement and micromachining techniques, Proc, of the 8 ^th Intern. Confer, on Solid-State Sensors and Actuators, and Eurosensors IX, TRANSDUCERS '95, Stockholm, Sweden, pp. 253-256.

Claims (1)

A two-dimensional magnetometer containing a semiconductor n-type substrate, on one side of which is formed an ohmic contact with a square shape and rectangular ohmic contacts symmetrically relative to it, a current source such as the external magnetic field lies in the plane of the semiconductor substrate, which is characterized by a square the contacts are two (2) and (3) and are located close to each other, at distances and symmetrically with respect to the four sides of each of them, one clockwise along one rectangular ohmic contour. kt - first (4) and (5), second (6) and (7), third (8) and (9) and fourth (10) and (11), all of equal size, each of the two groups containing a square (2) and (3) and four rectangular contacts (4) and (5), (6) and (7) and respectively (8) and (9), (10) and (11) are surrounded by a deep /> - ring type (12), the two square contacts (2) and (3) are connected to the current source (13), the first (4) and (5) and respectively the second (6) and (7) contacts of each group are interconnected , the fourth (10) and (11) and respectively the third (8) and (9) contacts of each group are the outputs (14) and (15) of the two-dimensional magnetometer for the two orthogonal components of the magnet the field of origin (16) lying in the plane of the i-type support (1). 4 · 4 ABSTRACT TWO-DIMENSIONAL MAGNETOMETER Chavdar Stanoev Roumenin Sia Valcheva Lozanova The two-dimensional magnetometer contains a semiconductor i-type support, on one side of which two square ohmic contacts (2) and (3) are formed adjacent to each other. Symmetrically with respect to their four sides, there is a clockwise sequence of one rectangular ohmic contact - first (4) and (5), second (6) and (7), third (8) and (9), and fourth (10) and ( 11), all equal in size. Each of the two groups containing square (2) and (3) and four rectangular contacts (4) and (5), (6) and (7) and respectively (8) and (9), (10) and (11) is surrounded by a deep / h-type ring (12). Contacts (2) and (3) are connected to a current source (13). The first (4) and (5) and the second (6) and (7) contacts of each group are connected respectively to each other. The fourth (10) and (11) and respectively the third (8) and (9) contacts of each group are the outputs (14) and (15) of the two-dimensional magnetometer for the two orthogonal components of the magnetic field (16) lying in the plane of i-type pad (1).