UA72826C2 - Magnetic field strength transducer - Google Patents

Abstract

The present invention relates to semiconductor magnetic field strength transducers using the Hall effect. The proposed transducer contains a substrate with a semiconductor layer, two current contacts, and a number of voltage contacts, which are connected to the semiconductor layer. Each currant contact is connected to one voltage contact. All the contacts of the transducer are arranged on one side of the semiconductor layer. The present invention allows the measurement accuracy of the transducer to be increased.

Description

Description of the invention

The invention relates to semiconductor magnetic field sensors that use the Hall effect. 2 A known measuring transducer of the magnetic field, which contains a semiconductor region formed on a substrate, typically rectangular in shape, and four terminals - one on each side of the semiconductor region. The two opposite terminals are current, and the other two are potential (K.5.

Roromis, Nar EpPesi YuOemisez, Adat Niideg, Vgivio!, Rnyade!rnia apa Mem Mogk, 1991. R.b1)|, Based on the Hall effect, such a converter allows measuring the magnetic field induction. However, its disadvantages are, firstly, the impossibility of measuring the spatial distribution of the magnetic field without corresponding spatial movement of the transducer, and secondly, the impossibility of measuring the magnetic field in close proximity to the source of the magnetic field (in particular, to the surface of the magnet).

A measuring transducer is known, which contains an area of a semiconductor layer formed on a substrate and two current terminals and several potential terminals connected to this area. Current terminals 12 are located on opposite sides of the semiconductor layer region, and potential terminals are located on other sides of this region and form pairs. Each pair of potential outputs is mirror-symmetrical relative to the conditional axis that connects the current outputs |K.5. Roromis, NaiiYi EbPbesi Oemisez, Adat Niyideg, VgivisII, RiyadeIrnia apa Mem Mogk, 1991. R.61). The voltage difference on each pair of potential terminals is proportional to the value of the current through the current terminals and the induction of the magnetic field in the region of the semiconductor layer, which is located between the potential terminals.

Having several pairs of potential outputs, such a converter allows measuring the magnetic field simultaneously at several points in space. That is, it becomes possible to measure the spatial distribution of the magnetic field without spatially moving the transducer.

However, as in this and the previously mentioned converter, the leads that surround the semiconductor layer on all sides, that is, the active region of the converter, do not allow this active region (3) to be brought closer to the source of the measured magnetic field. This worsens the accuracy of measuring the distribution of the magnetic field in close proximity to the field source.

The basis of the invention is the task of creating a magnetic field measuring transducer, in which the introduction of new elements and connections allows to increase the accuracy of measurements. at

The task is achieved by the fact that the measuring transducer of the magnetic field, which contains an area of the semiconductor layer formed on the substrate and two current terminals and several potential terminals connected to this area, according to the invention, has one potential terminal connected to each current terminal, and all the terminals of the converter are placed on the substrate only on one side of the area of the semiconductor layer.

Introduction of new elements and corresponding connections allows to create a measuring transducer in which - the semiconductor layer can be placed on the edge of the substrate, and thereby create conditions for the maximum approximation of the active area of the measuring transducer to the object of research. In turn, this increases the accuracy of measuring the spatial distribution of the magnetic field in the immediate vicinity of the source of this field. "

Figure 1 shows a diagram of a magnetic field measuring transducer, which has the following elements; And - With lining; Ii - semiconductor layer; PP - a pair of current terminals (contact pads 6, 7); IM - with potential outputs, the number of which determines the number of measurement points of the spatial distribution of the magnetic field

From" and can be arbitrary (contact pads 1, 2, 3, 4, 5); M - a pair of potential leads (contact pads 8, 9) which are connected to the corresponding current leads. All the terminals of the converter are placed on the substrate only on one side of the region of the semiconductor layer. The active area of the measuring transducer is -1 395 the semiconductor layer II in the zone of connection to it of the potential terminals of the IM. This active region is formed at the edge of the substrate |. ko In the process of measurement, the active area of the transducer is placed in a magnetic field, the spatial distribution of which along the X axis is the subject of research. The converter is powered by a source of direct current, which is connected to the current terminals I. ko 50. At the potential terminals, voltages are formed that have two components. The first component, which is determined

Ф redistribution of charge carriers drifting in the electric field is a useful signal. This component is a function of magnetic field induction in the active region of the measuring transducer. The second component, which is caused by the voltage drop on the semiconductor layer, is parasitic. Taking into account magnetoresistive and thermoresistive effects, the parasitic component is not a stable value and requires special compensation. 59 Therefore, unlike the closest analogue, in which the output signals (Hall voltages) are formed on

GF) pairs of potential terminals in a differential form, the output signals of the measuring converter according to 7 of the invention are formed on the potential terminals of the IM (except those connected to the current terminals) relative to the reference voltages. These reference voltages are obtained by dividing the voltage difference, which is formed on a pair of potential terminals M. because Thus, the useful signals of the measuring converter according to the invention are the voltage differences

M1-Mve/K, Mo-Mvo/Ko, ... Mai-Mvo/Ky, where Mi, Mo, ... My, - voltages on potential terminals (contact pads 1, 2, -.5 Fig. 1) ;

Mvo - voltage difference on the potential terminals (contact pads 8, 9), which are connected to the current terminals (contact pads 6, 7); K4, Ko, ...Ka - division coefficients. because Reference voltages Mab/K serve to compensate for parasitic components of the output signals and, thus,

ensure the selection of useful components that carry information about the values of magnetic field inductions

Вхх, Ухо, ... Вхп (in Fig. 1, the field induction vector is directed perpendicular to the surface of the substrate of the transducer e VI.

The introduction into the measuring converter according to the invention of the potential terminals U, which are connected to the current terminals Ii, ensure high accuracy of measuring the voltage drop on the semiconductor layer, which is the basis of the high accuracy of the formation of reference voltages.

The active area of the measuring transducer according to the invention can be placed at any small distance from the edge of the substrate. Depending on the transducer manufacturing technology (solid-state 70 integrated circuit technology, thin-film technology, volumetric structure technology, etc.), this distance can range from a few micrometers to several hundred micrometers.

In particular, using the traditional technology of thin-film Hall transducers on semiconductor materials of the A|Vu group, it is possible to manufacture a measuring transducer of the distribution of the magnetic field with a distance between the active area of the transducer and the research object of no more than 5Ωm, which is approximately 75 orders of magnitude less than the analogue. Thus, when studying near-surface magnetic fields at the minimum possible distances, for example bΩm from micro-objects or objects with a granular (domain) structure, the proposed measuring transducer allows to increase the accuracy of measuring the distribution of the magnetic field several times. ov

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I ee In cm

A Beiy ra y siy A oy o im MY m m/o m/ m/ Mm/ her (Se)

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Claims (1)

The formula of the invention is a measuring transducer of the magnetic field, which contains an area of the semiconductor layer formed on the substrate and two current terminals and several potential terminals connected to this area, which differs in that one potential terminal is connected to each current terminal, and all terminals of the converter are placed on the substrate only on one side of the region of the semiconductor layer. « t0 Official Bulletin "Industrial Property". Book 1 "Inventions, useful models, topographies of integrated microcircuits", 2005, M 4, 15.04.2005. State Department of Intellectual Property of the Ministry of Education and Science of Ukraine. ;" In the -and name) (ee) name) 4) name) 60 b5