BG66404B1 - Semiconductor hall element with a parallel axis of sensitivity - Google Patents

Abstract

The semiconductor Hall element with a parallel axis of sensitivity contains a semiconductor pad (1) with an impurity type conductivity, on one side of which three rectangular ohmic contacts are formed: first (2), second (3) and third (4), located in parallel to their long sides. The first (2) and the third (4) contacts are external and the second (3) is internal. The magnetic field (8) is appliedperpendicularly to the cross-section of the pad (1). The second contact (3) and one of the external contacts (4), through respective charge resistors (5 and 6) and a voltage source (7), are connectedwith the other external contact (2). The outlet (9) is the second (3) and the external contact (4), which is connected with a charge resistor (6).

Description

The invention relates to a Hall semiconductor element with a parallel axis of sensitivity, applicable in the field of measurement technology, low-field magnetometry, navigation, micro- and nanosensors, automotive, wireless communications, contactless automation and control, energy, positioning, positioning , medicine, military and security, and more.

BACKGROUND OF THE INVENTION

A Hall semiconductor element with a parallel axis of sensitivity is known, comprising a semiconductor substrate of impurity type, on one side of which three rectangular ohmic contacts, first, second and third, parallel to each other, are formed at regular intervals. countries. The first and third contacts are terminal and are connected to both a power source in current generator mode and to two series resistors connected in series. The second contact is internal and output (Hall). The external magnetic field is applied perpendicular to the cross-section of the semiconductor substrate and is parallel to the long sides of the rectangular ohmic contacts, the output being the Hall contact and the common point of connection of the two resistors [1].

The disadvantage of this Hall semiconductor element with the parallel axis of sensitivity is the low magnetic sensitivity, since only half of the total Hall voltage generated in this converter element can be removed from the output.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a Hall semiconductor element with a parallel axis of sensitivity with a high value of magnetic sensitivity.

This problem is solved by a Hall semiconductor element with a parallel axis of sensitivity containing a semiconductor substrate of impurity type mixed on one side of which three rectangular ohmic contacts, first, second and third, parallel to each other, are formed on one side its long sides. The first and third contacts are terminal and the second is internal. The second contact and one of the end contacts through the respective load resistors and a voltage source are connected to the other end contact. The external magnetic field is applied perpendicular to the cross-section of the semiconductor substrate and parallel to the long sides of the rectangular ohmic contacts, and the output is the second and third terminal contacts connected to the load resistor.

Explanation of the attached figure

The invention is illustrated in more detail with the accompanying figure, which is a cross-section of an embodiment thereof.

Examples of carrying out the invention

The Hall semiconductor element with a parallel axis of sensitivity comprises a semiconductor substrate 1 with impurity type, on one side of which three rectangular ohmic contacts are formed, first two, second 3 and third 4, arranged parallel to their long countries. The first 2 and third 4 contacts are terminal and the second 3 is internal. The second contact 3 and one of the end contacts 4 through the respective load resistors 5 and 6 and a voltage source Ί are connected to the other terminal contact 2. The external magnetic field 8 is applied perpendicular to the cross section of the semiconductor substrate 1 and parallel to the long sides of the rectangles ohmic contacts 2,3 and 4 and output 9 is the second contact 3 and the terminal 4 connected to the load resistor 6.

The action of a Hall semiconductor element with a parallel axis of sensitivity according to the invention is as follows.

When the power source is turned on

7, between the end (third) contact 4 with the load resistor 6 connected thereto and the other end (first) contact 2, and respectively between the second (internal)

66404 Bl contact 3 and end (first) contact 2 without load resistor two direct currents 1 ₄₂ and 1 ₃ flow,. Because the ohmic contacts 2, 3 and 4 are planar and represent equipotential planes, the currents through them I ,, 1 ₃ and 1 _{4 are} initially perpendicular to the upper surface of the substrate 1 and penetrate into its volume. Then the current trajectories become parallel to the surface. 1. For example, when there is a temperature T different from the surface of the semiconductor substrate 1 from currents 1 and 1; the presence of mechanical stresses from the enclosure of the chip with the Hall element; applying insulating dielectric coatings, conductive thin layers or rails to the substrate 1 in the process; inevitable geometric lithographic errors or tolerances in the arrangement of ohmic contacts 2, 3 and 4; heterogeneities in the alloy of the pad 1; the different length of current paths between contacts 4 and 2, and respectively 2 and 3, etc. both currents 1 ₄ , and 1 _Ί inevitably generate offset. This means that a parasitic output voltage V ₃₄ (B = 0) / 0 occurs at the output 9 between the second 3 and the terminal (third) contact 4, which is connected to the load resistor 6 in the absence of a magnetic field B 8, B = 0. Its compensation (including zeroing) is easily achieved by varying the value of one of the two load resistors 5 or 6. By virtually changing the values of the two currents 1 _4L and 1 ₃ , the equipotential of the output contacts 3 and 4 is achieved. exceed the input impedance of semiconductors by at least one order Hall's element. Resistors 5 and 6 together with the voltage source 7 form the fixed values of the two supply currents 1 _{4 2} and 1 _{3 2} .

The application of an external magnetic field B 8 perpendicular to the cross-section of the semiconductor substrate 1 and parallel to the long sides of the rectangular contacts 2,3 and 4 by the Lorentz force F _L = qV _dr x B leads to deflection and deformation of both directions in general. 1 ₄ , and 1 ₃ ,, V _dr is the drift velocity of the carriers, q is the electron load. For example, the two current trajectories 1 ₄₂ and 1 ₃ , depending on the direction of the magnetic field B 8, either "shrink" to the upper surface of the substrate 1, or simultaneously "expand" inward in volume. As a result, on the upper surface of the substrate 1, where the inner ohmic contacts 3 and the third (outer) 4 are located, the magnetic field B and the currents 1 ₃ and 1 ₄ generate simultaneously two opposite Hall potentials. Furthermore, the current 1 _{4 2} , in the heap of its trajectory, when parallel to the surface of the substrate 1, induces an additional Hall potential in the area with the second (internal) 3 contact. Therefore, the full Hall voltage V ₃₄ (B) generated in the sensor, and not only half of it as in the known technical solution, is developed and measured at the output 9. Therefore, the magnetic sensitivity increases twice.

The unexpected positive effect of the new Hall element with a parallel axis of sensitivity, which doubles its magnetic sensitivity in comparison with the known one, is that at each of contacts 3 and 4 of the differential output 9 are formed in the magnetic field B 8 simultaneously by Hall potentials with opposite sign. In Hall's famous sensor, however, only one contact actually acts as Hall. In the new solution, they are two - 3 and 4. Also, the outgoing Hall contacts 3 and 4 are next to each other, contrary to the generally accepted practice of alternating sensor and power contacts. This circumstance also helps to obtain the full Hall voltage at the output 9.

Experiments with the n-type silicon Hall elements with a parallel axis of sensitivity according to the invention demonstrate an increase in the magnetic sensitivity twice in comparison with the known solution.

The preferred technology for implementing the new Hall micro converter is CMOS. N-GaAs epitaxial technology can also be successfully used, which dramatically increases the sensitivity of the microsensor, especially for security and military purposes.

Claims

Claims (1)

1. A Hall semiconductor element with a parallel axis of sensitivity, comprising a semiconductor substrate of impurity type, on one side of which three rectangular ohmic contacts are formed consecutively and at a distance, first, second and third, parallel to their long sides, the first and third contacts being terminal, the second being internal, and the magnetic field applied 66404 Bl perpendicular to the cross-section of the support and parallel to the long sides of the rectangular ohmic contacts, characterized in that the second contact (3) and one of the end contacts (4) through respective load resistors (5 and 5 6) and a source of voltage (7) is connected to the other end contact (2), and the output (9) is the internal contact (3) and the end contact (4) that is connected to the load resistor (6). Attachment: 1 figure