BG66704B1 - Two-dimensional semiconductor magnetometer - Google Patents

Abstract

The two-dimensional semiconductor magnetometer contains solid-state n-type pad (1), on one side of which have formed a central ohm contact (2) with a square-shaped and symmetrical to it rectangular ohm contacts (3, 4, 5 and 6), current source (19). Magnetic field (20) lies in the plane of the pad (1). Surface n-type areas (7, 8, 9 and 10), located between the four sides of the socket (2) and four socket (3, 4, 5 and 6) are limited with deep heavily doped p +-type areas (11, 12, 13 and 14). The rectangular contacts (3, 4, 5 and 6) are connected through the same cargo value resistors (15, 16, 17 and 18) with one conclusion of current source (19), the conclusion of which is incorporated with the contact (2). Р +-type areas (11, 12, 13 and 14) are associated with each other and with the midpoint of the high Ohm trimmer (20), which is connected to the current source (19). Couples facing contacts (3 and 5) and respectively (4 and 6) versus the central contact (2) are outputs (21 and 22) for both orthogonal Planar components of the vector of the magnetic field (20).

Description

(54) TWO-DIMENSIONAL SEMICONDUCTOR MAGNETOMETER

Field of technology

The invention relates to a two-dimensional semiconductor magnetometer applicable in the field of sensors, positioning of objects in the plane, automation, control and measurement technology and low-field magnetometry, micro- and nanotechnologies, systems engineering, robotics and mechatronics, biomedical research and noncontact linear displacements, energy and energy efficiency, military affairs, security, etc.

BACKGROUND OF THE INVENTION

A two-dimensional semiconductor magnetometer is known, comprising a n-type semiconductor substrate, on one side of which a central ohmic contact of square shape is formed as at distances and symmetrically with respect to its four sides there is one rectangular inner ohmic contact and one outer ohmic contact. The four external contacts are connected and are connected to the central contact via a power source. The measured external magnetic field lies in the plane of the n-type substrate as each pair of opposite internal contacts relative to the central one are the outputs for the two orthogonal plane components of the magnetic field vector [1, 2].

A disadvantage of this two-dimensional semiconductor magnetometer is the reduced magnetic sensitivity of the two sensor channels when measuring the planar components of the magnetic field as a result of the surface leakage of the four supply currents between the central and end contacts.

Another disadvantage is the reduced accuracy of the two outputs as a result of the parasitic influence of the surface components of the supply current between the central and end contacts.

Technical essence of the invention

The object of the invention is to provide a two-dimensional semiconductor magnetometer with high magnetic sensitivity and measuring accuracy of the two sensor channels.

This problem is solved with a two-dimensional semiconductor magnetometer containing a n-type semiconductor substrate, on one side of which are formed a central ohmic contact with a square shape as at short distances and symmetrically to its four sides there is a rectangular ohmic contact. The inner surface n-type areas located between the four sides of the central contact and the four rectangular contacts are bounded by deep heavily doped p ⁺ -type zones. The rectangular contacts are connected through equal load resistors to one terminal of the current source, the other terminal of which is connected to the central contact. The P ⁺ -type zones are connected to each other and to the midpoint of a high-resistance trimmer, which is connected to the terminals of the current source. The measured external magnetic field lies in the plane of the n-type substrate and the pairs of opposite contacts to the central one are the outputs for the two orthogonal plane components of the magnetic field vector.

An advantage of the invention is the high magnetic sensitivity of the two sensor channels as a result of the strongly reduced flow of the four components of the supply current from the deep p ⁺ -type zones thus formed and polarized in the opposite direction to the substrate.

Another advantage is the high measuring accuracy of the two sensor outputs due to the greatly reduced parasitic influence between the surface components of the supply current between the central and rectangular contacts through the p ⁺ -type zones surrounding the active converter! sectors of the two-dimensional magnetometer.

Another advantage is the simplified instrument design, containing a total of five instead of nine sensor contacts.

Explanation of the attached figure

The invention is illustrated in more detail by one of its embodiments given in the attached figure 1.

Descriptions of granted patents for inventions

Examples изпълнение 08.2 / 31.08.2018

The two-dimensional semiconductor magnetometer contains a n-type semiconductor substrate 1, on one side of which are formed a central ohmic contact 2 with a square shape as at short distances and symmetrically to its four sides there is a rectangular ohmic contact 3, 4, 5 and 6. The inner surface n-type areas 7, 8, 9 and 10 located between the four sides of the central contact 2 and the four rectangular contacts 3, 4, 5 and 6 are bounded by deep strongly doped p ⁺ -type zones 11, 12, 13 and 14 The rectangular contacts 3, 4, 5 and 6 are connected through equal load resistors 15, 16, 17 and 18 with one terminal of source 19, the other terminal of which is connected to the central contact 2. P ⁺ -type zones 11,12, 13 and 14 are connected to each other and to the midpoint of a high-resistance trimmer 20 which is connected to the terminals of the current source 19. The measured external magnetic field 21 lies in the plane of the n-type substrate 1 as the pairs of opposite contacts 3 and 5 and 4 and 6 against the cent the real 2 are the outputs 22 and 23 for the two orthogonal plane components of the magnetic field vector 21.

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

When switching of the contacts 2, 3, 4, 5 and 6 to the power source 19 between the ohmic terminals 2 and respectively 3, 4, 5 and 6 run four components II 1 ₂₅ and I of the power through contact 2 current 1 _2. The current trajectory in the areas under contacts 2, 3, 4, 5 and 6 is initially perpendicular to the upper surface of the n-substrate 1, penetrates deep into the volume of the semiconductor structure 1, as the low-resistance contacts 2, 3, 4, 5 and 6 are located at short distances from the central contact 2 and represent equipotential planes. Then the effective current trajectories 1 ₂ in the volume of the n-substrate 1 become parallel to its upper surface. An important feature is that the directions of components 1 ₂₃ and - 1 ₂₅ are opposite. The same applies to the other current components I and - I. The deep p ⁺ -type zones 11, 12, 13 and 14, surrounding the inner surface n-regions 7, 8, 9 and 10 located close enough between the ohmic contacts 2, 3, 4, 5 and 6 significantly reduce the flow on the surface of the substrate 1 of the currents 1 _{2 3} , 1 _{2 4} , 1 _{2 5} and 1 _{2 6} . Through the trimmer 20 and the current source 19, the p ⁺ -type zones 11, 12, 13 and 14 are switched in the opposite direction to the n-substrate.

1. Through the extended from the reverse voltage on the four p ⁺ -n diode junctions areas of space load, even more efficiently locate the supply current components II 1 ₂ and 1 _{2 6} in the near-surface area of structure 1 by drastically minimizing the leakage of current components . The same value load resistors 15, 16, 17 and 18, R ₁ = R ₂ = R ₃ = R ₄ , guarantee the mode of operation of the 2-D sensor current generator and equality of components 1 ₂₃ = -1 = 1 = -1 = const. If in the case of structural asymmetry there is an inequality of these currents, their equalization is done with additional trimmers connected to their endpoints to contacts 3 and 5, and respectively 4 and 6. Thus the inevitable offset of outputs 22 and 23 in the absence of magnetic field B 20 (B = 0) is easily compensated (reset) by changing the value of the resistances through the trimmers in the respective circuits containing contacts 3, 4, 5 and 6.

The external magnetic field B 20, which lies in the plane of the substrate 1 and is of arbitrary orientation, through its two mutually perpendicular components Β _χ and B leads to the emergence of corresponding laterally deflecting moving current carriers Lorentz forces, F _L = qV _di x B, where q is the elementary load of the electron, a is the vector of the average drift velocity of the moving current carriers, in our case the electrons. Since the distances between the central 2 and the rectangular contacts 3, 4, 5 and 6 are short and the supply currents penetrate deep into the volume of the substrate 1, the effect of the Lorentz force F _L on these parts of the trajectories is maximum. As a result of the Lorentz deflection F _{L, the} trajectories of the oppositely directed current components 1 ₂ -1 ₂ and 1 _{2 4} , - 1 _{2 6} “shrink” and “expand”, respectively. Depending on the direction of the magnetic vector B 20, each of the pairs of opposite currents increases or decreases at the expense of the other. Due to the operating mode of the current generator I _{2 3} = -1 ₂ = I ₂ = -1 _{2 6} = const, instead of changes of the individual current components through contacts 3 and 5, and respectively 4 and 6, opposite terminals are generated on these terminals. sign potentials. This leads through the Hall effect to the occurrence of the two differential outputs 22 and 23 Hall voltages V _{3 5} (Β _χ ) Υ ₂₁ (Β _χ ) 22 and V _{4 6} (B) V ₂₂ (By) 23. These output signals 22 and 23 are linear and

Descriptions of issued patents for inventions № 08.2 / 31.08.2018 odd functions of the magnetic vectors Β _χ and В _у . The increase in the magnetic sensitivity is due to the limiting and inversely polarized p ⁺ -type zones 11,12,13i14. This innovative approach drastically reduces the flow of supply current in the surface area of the substrate 1, improving the orthotonality of the respective current components I2 -1 I and -1 relative to the two planar vectors Βχ and B of the magnetic field B 20, which also increases the magnetic sensitivity. The increased accuracy in the measurement of the individual vectors Βχ and Vu is related to the significant restriction of the flow on the surface of the substrate 1 of the four components 12 3, -12 12 and -12 6 by means of the p ⁺ -type zones 11, 12, 13 and 14. This greatly reduces the mutual parasitic influence of the two sensor channels 22 and 23 and guarantees high metrological quality of the 2-D magnetometer. A simplification of the instrument design has been achieved, which contains five - 2, 3, 4, 5 and 6 instead of nine sensor ohmic contacts as in the known solution. The absolute value of the vector of the magnetic field B 20 in the plane x-y of the n-substrate 1 and the angle Θ of the field B 20 with respect to a fixed reference axis in the same plane are given by the expressions: | = (Βχ ² + Vu ² ) ^1/2 and Θ = tan ¹ (Vy (B _y ) / V _x (B _x )).

The unexpected positive effect of the new technical solution lies in the originality of the selected instrument design, containing only five ohmic contacts and limiting the surface current flow back polarized deep p ⁺ -zones 11, 12, 13 and 14. In addition, the design allows to increase the magnetic sensitivity and the accuracy of the 2-D sensor by drastically reducing surface parasitic currents. The two-dimensional semiconductor magnetometer can be realized with various modifications of the planar silicon technology CMOS, BiCMOS, SOS, and if necessary micromachining silicon processes can be used.

Claims (1)

Patent claims A two-dimensional semiconductor magnetometer comprising a semiconductor p-type substrate, on one side of which a central ohmic contact with a square shape and rectangular ohmic contacts symmetrically relative to it are formed, a current source with an external magnetic field lying in the plane of the p-type substrate characterized in that the rectangular contacts are four (3, 4, 5 and 6) and are located at short distances from the four sides of the central contact (2), the inner surface n-type areas (7, 8,9 and 10), located between the four sides of the central contact (2) and the four rectangular contacts (3, 4, 5 and 6) are bounded by deep strongly doped p ⁺ -type zones (11,12,13 and 14), as the rectangular contacts , 5 and 6) are connected through equal value resistors (15, 16, 17 and 18) with one terminal of the source (19), the other terminal of which is connected to the central contact (2), where p ⁺ -type the zones (11,12,13i14) are connected to each other and to the midpoint of the high-ominous tr dimension (20), which is connected to the terminals of the current source (19), as the pairs of opposite contacts (3 and 5) and respectively (4 and 6) relative to the central contact (2) are the outputs (22 and 23) for the two orthogonal plane components of the magnetic field vector (21).