JPH084160B2 - Magnetoresistive element and manufacturing method thereof - Google Patents

Description

The present invention relates to a magnetoresistive element using a high mobility semiconductor crystal such as indium antimonide InSb and a method for manufacturing the same.

(B) Conventional Technology Since a magnetoresistive element using a high-mobility semiconductor crystal has high sensitivity and low noise, it has been put into practical use as a highly accurate magnetic sensor.

The resistance value R of this kind of magnetoresistive element is expressed by the following equation when the change in resistivity is small.

However, R ₀ is a reference resistance when no magnetic field is applied, l is length, w is width, μ is electron mobility, and B is magnetic flux density.

In order to increase this resistance value change, it is sufficient to decrease l / w in the equation (1). Therefore, in the conventional device, as shown in FIG. 6, a short-circuit wire (22) such as a silver wire is attached to the surface of the magnetoresistive element (21) or vacuum evaporation is performed to short-circuit the Hall voltage. The method has been adopted (see Japanese Patent Publication No. 42-7984).

(C) Problems to be solved by the invention Since the above-described magnetoresistive element uses the silver wire as the short-circuit line for short-circuiting the Hall voltage, the magnetic flux passing through the element also passes through the area of the short-circuit line, The magnetic flux density B in the equation (1) cannot be increased.

The present invention has been made in view of the above points, and an object of the present invention is to provide a magnetoresistive element capable of increasing the magnetic flux density B and increasing the change in the resistance value R depending on the presence or absence of magnetic flux, and a method for manufacturing the same. Is.

(D) Means for Solving the Problems In order to solve the problems, the magnetoresistive element of the present invention uses a superconducting piece as a short-circuit line for short-circuiting a Hall voltage, and a magnetic flux is generated between adjacent superconducting pieces. It is a thing to concentrate.

Further, the device manufacturing method is characterized in that after forming a superconducting piece in a stripe shape on a substrate, a semiconductor having high mobility is coated thereon.

(E) Operation Since the short-circuit line that short-circuits the Hall voltage in the magnetoresistive element is composed of superconducting pieces, the magnetic flux entering the element will not pass through the superconducting pieces but will be concentrated between adjacent superconducting pieces. ,
The magnetic flux density B is increased as compared with the above-mentioned one using a silver wire for the short-circuited side. Therefore, the resistance value R becomes large.

Further, since the superconducting piece is used, this element is used at a low temperature, so that the electron mobility μ is also large and the resistance value R is further increased.

Furthermore, if the number of superconducting pieces as short-circuit wires is large,
The l / w in the equation (1) becomes small, and the linearity of the resistance change in the low magnetic field region is improved.

On the other hand, according to the manufacturing method of the present invention, a superconducting wire can be used as a short-circuit wire for short-circuiting the Hall voltage in the magnetoresistive element, and a magnetoresistive element with a large change in resistance value can be manufactured.

(F) Example An example of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of a magnetoresistive element. In this figure, a plurality of superconducting pieces (4) as short-circuiting lines for short-circuiting the Hall voltage are provided between the electrodes (2) and (3) of the semiconductor (1) having a high electron mobility. As the semiconductor (1), indium antimonide InSb is used in the embodiment.
However, indium arsenide InSb and gallium arsenide GaAs may be used. Further, as the superconducting piece (4), an oxide superconducting material was used. Specifically, Y was used as A of the A-Ba-Cu-O system, but as A, Yb, E
Those selected from r, Gd, Dy, Ho, Eu, Sm, and Nd may be used.

In FIG. 1, the electrodes (2) and (3) on both ends are
Lead wires (5) are connected to each.

 The magnetoresistive element (6) is manufactured as follows.

First, a substrate (7) is prepared as shown in FIG. This substrate is made of Al ₂ O ₃ , MgO or glass. A plurality of superconducting pieces (4) are formed in stripes on this substrate (7).

This superconducting piece may be formed by applying a molten superconducting material, but in the embodiment, it was formed by the sputtering device shown in FIG. In the figure, an exhaust system (9) is connected to a bell jar (8) of a spattering device, and an argon gas cylinder (10) for supplying an argon gas as a discharge gas into the bell jar is provided with a variable leak valve (11) and a stop valve (10). 12) is connected through. In the bell jar (8), the counter electrodes (13) and (14) have shutters (1
7) are counter-placed through. The anode (13) is grounded and the substrates (7), (7) on which the superconducting thin film is deposited are placed on the surface thereof. The cathode (14) is made of a target material made of a Y-Ba-Cu-O-based sintered body which is a superconducting material, and a high negative voltage is applied to the cathode (14). (15) and (16) are high and low vacuum gauges.

Then, argon gas is supplied from the argon gas cylinder (10) into the bell jar (8) at a pressure of 1 to 10 ^-4 Torr, and at the same time, a voltage of 15 Kv is applied between the counter electrodes (13) and (14). A glow discharge is generated between the counter electrodes (13) and (14). At this time, the temperature of the anode (13) on which the substrate (7) is placed is kept at room temperature or at most 100 ° C.
When the shutter (17) is opened in this state, the Y-Ba-Cu-O-based sintered body forming the cathode (14) is sputtered and scattered on the substrates (7) and (7). The material of the sintered body that has reached the substrates (7) and (7) is crystallized on the substrate surface because the substrate is in a low temperature state in the striped unmasked region on the substrate (7). Instead, it deposits in an amorphous state. Therefore, a plurality of stripe-shaped superconducting pieces (4), (4) are formed on the substrate. When the mask is removed in this state, the result is as shown in FIG.

Then, the semiconductor (1) having high electron mobility is coated on the substrate (7) and the superconducting pieces (4) and (4) by sputtering or vapor deposition (FIG. 2 (c)). By removing the substrate (7), the magnetoresistive element (6) shown in FIG. 1 is obtained.

Thus, in the conventional device in which the short-circuit line (22) for short-circuiting the Hall voltage of the magnetoresistive element (21) is made of a silver wire, as shown in FIG. Since the incoming magnetic flux passes evenly in the short-circuit line area,
The magnetic flux density between the adjacent short-circuit wires (22) and (22) is not particularly increased.

Further, in the conventional device that short-circuits the Hall voltage with the short-circuit wire (22), a silver wire, a copper wire, or an indium wire is used as the short-circuit wire (22), so that the electric field between both ends that generates the Hall voltage can be weakened. However, the degree of indium wire is about 60% and that of silver wire or copper wire is about 80%, and the change in resistance value cannot be further increased due to the influence of the electric field.

On the other hand, in the magnetoresistive element (6) according to the present invention, the magnetic flux that tries to enter the region of the superconducting piece (4) which is a short-circuit line is transferred to the superconducting piece due to the Meissner effect of the superconducting piece (4). Of the superconducting pieces (4), (4) are concentrated and flow, as shown in FIG. Therefore, the magnetic flux density between the superconducting pieces (4) and (4) is larger than that in FIG.

Further, since the short-circuit wire is composed of the superconducting piece (4), the both ends that generate the Hall voltage are connected by the superconducting piece (4) with zero internal resistance, so that the both ends have the same potential. No electric field is generated between them. Therefore, the influence of the electric field is eliminated, and the change in resistance value due to the presence or absence of magnetic flux becomes larger than that of the conventional one.

In addition, in the examples, the superconducting piece (4) is replaced with Y-Ba-
Since it is composed of Cu-O type, the boiling point of liquid nitrogen (77
K) becomes superconducting at higher ambient temperature. Therefore, the magnetoresistive element (6) according to the present invention is used at a low temperature. Therefore, the electron mobility in the semiconductor (1) can be increased as compared with the conventional one that is used at room temperature. In the example, indium antimonide InSb is used as a semiconductor, and its electron mobility μ is 80,000 cm ² / (v · s) at room temperature, whereas it is 40 at 77K.
It becomes as large as 0,000 cm ² / (v · s). Therefore, the resistance value changes greatly depending on the presence or absence of a magnetic field.

Since the electron mobility μ and the magnetic flux density B increase, the change in the resistance value improves the linearity with respect to the change in the magnetic flux density B. FIG. 5 is a characteristic diagram of X according to the embodiment and the above-mentioned conventional Y.

(G) Effect of the Invention The present invention is directed to between both electrodes of a semiconductor having high electron mobility,
Since it is characterized by providing a plurality of superconducting pieces for short-circuiting the Hall voltage and concentrating magnetic flux between adjacent superconducting pieces, it is possible to provide a magnetoresistive element having a large resistance value change depending on the presence or absence of magnetic flux. it can.

In addition, since a magnetoresistive element is manufactured by forming a stripe-shaped superconducting piece on a substrate and then coating a semiconductor with high electron mobility on it, a magnetoresistive element with a large resistance value change depending on the presence or absence of magnetic flux. Can be manufactured.

[Brief description of drawings]

1 to 5 show an embodiment of the present invention, FIG. 1 is a perspective view of a magnetoresistive element, and FIGS. 2 (a), (b) and (c) are views for explaining the manufacturing process, and FIG. FIG. 4 is a conceptual diagram of the sputtering device, FIGS. 4 (a) and 4 (b) are explanatory views of passage of magnetic flux in the embodiment and the conventional one, and FIG. 5 is a magnetic flux density-resistance value characteristic diagram of the magnetoresistive element. . FIG. 6 is a perspective view of a conventional magnetoresistive element. (1) ... Semiconductor, (2), (3) ... Electrode, (4) ...
… Superconducting piece, (7) …… Substrate.

Claims (2)

[Claims] 1. A semiconductor having high electron mobility between electrodes at both ends,
A magnetoresistive element characterized in that a plurality of superconducting pieces for short-circuiting a Hall voltage are provided, and magnetic flux is concentrated between adjacent superconducting pieces. 2. A method of manufacturing a magnetoresistive element, which comprises forming a stripe-shaped superconducting piece on a substrate and then coating a semiconductor having a high electron mobility thereon.