JPH09162459A - Differential semiconductor thin film magnetoresistive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent electric crosstalk between rows of elements by defining the specific resistance and thickness of the Si substrate of a differential semiconductor thin film magnetoresistive device comprising two rows of semiconductor thin film magnetoresistive elements obtained by forming a large number of short-circuit electrodes on a semiconductor thin film of high electron mobility, formed directly on the same Si substrate. SOLUTION: A differential semiconductor thin film magnetoresistive device 6 is composed of two rows of semiconductor thin film magnetoresistive element 4, 5 wherein a large number of short-circuit electrodes 3 are formed on an InSb thin film 2. The specific resistance and thickness of Si substrate 1 are controlled to 1kΩ.cm or above and 100μm or below, respectively. The sheet resistance of the Si substrate 1 is 100 kΩ/square or above at room temperature. If a highly oriented and epitaxially grown material excellent in crystallinity is used on the Si substrate, it is required that the specific resistance at room temperature should be 6mΘ.cm and the film thickness be 3μm at which the electron mobility having influence on magnetic characteristics is saturated. Thus the sheet resistance is 20kΩ/square. This prevents electric crosstalk between rows of elements.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor thin film magnetoresistive element used for detecting rotation, displacement, etc.
The present invention relates to a differential semiconductor thin film magnetoresistive element including two semiconductor thin film magnetoresistive element arrays in which a large number of short-circuit electrodes are formed on a semiconductor thin film having a high electron mobility formed directly on an i substrate.

[0002]

2. Description of the Related Art Generally, an optical sensor is used as a rotation sensor.
There are various types including a magnetic type. Among them, a magnetic method which is relatively insensitive to the influence of the atmosphere, such as dirt and dust, is most advantageous.

On the other hand, there are various types of magnetic systems, such as an electromagnetic pickup, a Hall element, and a magnetoresistive element.

[0004] In recent years, as various types of sensor elements are mounted with the electronic control of automobiles, Hall elements (Hall ICs), ferromagnetic thin-film magnetoresistive elements, and semiconductor magnetoresistive elements are used as rotation sensors, particularly gear sensors. Rotation sensors have been studied in various places from the point of zero speed detection, but when used as automobile rotation sensors, the operating temperature range of the element is -40 to 40.
Must meet + 150 ° C.

However, the Hall element, Hall IC, and ferromagnetic thin film magnetoresistive element having such temperature durability all have a small detection output of the detecting element itself, and secure a sufficient air gap with the object to be detected. And it is difficult to use it as a gear sensor.

On the other hand, a semiconductor magnetoresistive element is originally considered to be most suitable as a gear sensor because it has a large detection output and a wide air gap with the object to be detected. The operating temperature range of the InSb magnetoresistive element, which is an element, is −4.
The temperature of 0 to + 120 ° C. is not always sufficient in terms of temperature durability as the above-mentioned automobile rotation sensor.

[0007] Many of the InSb magnetoresistive elements widely used at present are of the InSb bulk single crystal flake type.
This is because the detection output of this element is InSb
This is because it is proportional to the electron mobility of, and is therefore greatly affected by its crystallinity. On the other hand, in this type of device, since a single crystal wafer is bonded onto a substrate via an adhesive layer and then polished to a thickness of 10 μm or less by non-strain polishing, as a result, the adhesive layer to InSb Due to the difference in expansion coefficient between layers, it has a drawback that it is weak against heat shock at low temperature to high temperature.

On the other hand, a semiconductor thin film magnetoresistive element having an InSb thin film heteroepitaxially grown on a Si wafer substrate directly as a seed substrate as described in JP-A-5-147422 and the like has the above temperature. It is useful because it has excellent durability and sensitivity comparable to that of a single crystal type.

[0009]

As described above, the above InS
A semiconductor thin film magnetoresistive element having excellent characteristics can be realized by using a Si wafer structure for the b epitaxially grown thin film, but there is one major problem here. This is because the Si wafer is a semiconductor and is not insulating as a substrate. Specifically, the left and right semiconductor thin-film magnetoresistive element arrays having the same structure that are practically used are connected via a midpoint. In the case where the differential type element is formed on the same substrate, the temperature characteristic of the midpoint potential is not always good due to electrical crosstalk between the two element rows (current flows to the substrate). In particular, there was a big problem for zero speed detection.

According to the present invention, in a differential type semiconductor thin film magnetoresistive element having a structure in which an InSb epitaxially grown thin film having such excellent output sensitivity characteristics and high temperature durability is directly formed on a Si wafer substrate, left and right magnetoresistive element arrays are provided. A main object of the present invention is to provide a differential semiconductor thin film magnetoresistive element that reduces electrical crosstalk between them and realizes excellent temperature characteristics of a midpoint voltage.

[0011]

In order to achieve the above object, the differential semiconductor thin film magnetoresistive element of the present invention has the same S
A semiconductor thin film having a high electron mobility, which is directly epitaxially grown on an i substrate, specifically, a differential semiconductor thin film composed of two semiconductor thin film magnetoresistive element arrays in which a large number of short-circuit electrodes are formed on an InSb thin film. In the magnetoresistive element, the following is used for the Si substrate.

(1) The specific resistance of the Si substrate is 1 kΩ · cm
The above is used and the thickness is 100 μm or less.

(2) The Si substrate having a Si oxide layer parallel to the surface of the substrate embedded in the substrate is used.

(3) The Si substrate has a PN junction in the substrate in parallel with the substrate surface.

(4) The Si substrate has a PN junction inside the substrate in parallel with the substrate surface, and an embedded layer having a polarity different from the conductivity type of the Si substrate directly contacting the semiconductor thin film is provided between the two semiconductor thin films. What is formed in the direction perpendicular to the substrate surface so as to separate the magnetoresistive element rows is used.

(5) A region of the Si substrate where the semiconductor thin film magnetoresistive element is not formed is doped with oxygen or nitrogen.

(6) A region of the Si substrate on which the semiconductor thin film magnetoresistive element is not formed is anodized.

(7) A region of the Si substrate on which the semiconductor thin film magnetoresistive element is not formed is subjected to plasma treatment so that its surface is oxidized or nitrided.

(8) An Si substrate having a groove formed in the thickness direction of the substrate so as to separate the two semiconductor thin film magnetoresistive element arrays is used.

(9) Use is made of a structure in which each of the Si substrates on which the two semiconductor thin film magnetoresistive element arrays are formed is divided.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention is two semiconductor thin films in which a large number of short-circuit electrodes are formed on a semiconductor thin film having high electron mobility formed directly on the same Si substrate. A differential semiconductor thin film magnetoresistive element composed of a magnetoresistive element array, wherein the Si substrate has a specific resistance of 1 k.
It is a differential semiconductor thin film magnetoresistive element characterized by having an Ω · cm or more and a thickness of 100 μm or less.

The invention according to claim 2 of the present invention is the same S
A differential type semiconductor thin film magnetoresistive element composed of two semiconductor thin film magnetoresistive element rows in which a large number of short-circuit electrodes are formed on a semiconductor thin film having a high electron mobility formed directly on an i substrate, A differential semiconductor thin film magnetoresistive element characterized in that the Si substrate has a Si oxide layer embedded in the substrate and parallel to the surface of the substrate.

The invention according to claim 3 of the present invention is the same S
A differential type semiconductor thin film magnetoresistive element composed of two semiconductor thin film magnetoresistive element rows in which a large number of short-circuit electrodes are formed on a semiconductor thin film having a high electron mobility formed directly on an i substrate, This is a differential semiconductor thin film magnetoresistive element characterized in that the Si substrate has a PN junction in parallel with the substrate surface inside the substrate.

The invention according to claim 4 of the present invention is the same S
A differential type semiconductor thin film magnetoresistive element composed of two semiconductor thin film magnetoresistive element rows in which a large number of short-circuit electrodes are formed on a semiconductor thin film having a high electron mobility formed directly on an i substrate, The Si substrate has a PN junction in parallel with the substrate surface inside the substrate, and a buried layer having a polarity different from the conductivity type of the Si substrate directly contacting the semiconductor thin film is provided between the two semiconductor thin film magnetoresistive element arrays. A differential type semiconductor thin film magnetoresistive element characterized by being formed in a direction perpendicular to a substrate surface so as to be separated.

The invention according to claim 5 of the present invention is the same S
A differential type semiconductor thin film magnetoresistive element composed of two semiconductor thin film magnetoresistive element rows in which a large number of short-circuit electrodes are formed on a semiconductor thin film having a high electron mobility formed directly on an i substrate, The differential semiconductor thin film magnetoresistive element is characterized in that a region of the Si substrate on which a semiconductor thin film is not formed is doped with oxygen or nitrogen.

The invention according to claim 6 of the present invention is the same S
A differential type semiconductor thin film magnetoresistive element composed of two semiconductor thin film magnetoresistive element rows in which a large number of short-circuit electrodes are formed on a semiconductor thin film having a high electron mobility formed directly on an i substrate, The differential semiconductor thin film magnetoresistive element is characterized in that a region of the Si substrate on which the semiconductor thin film is not formed is anodized.

The invention according to claim 7 of the present invention is the same S
A differential type semiconductor thin film magnetoresistive element composed of two semiconductor thin film magnetoresistive element rows in which a large number of short-circuit electrodes are formed on a semiconductor thin film having a high electron mobility formed directly on an i substrate, A differential semiconductor thin film magnetoresistive element characterized by oxidizing or nitriding the surface of a region of the Si substrate on which a semiconductor thin film is not formed by plasma treatment.

The invention according to claim 8 of the present invention is the same S
A differential type semiconductor thin film magnetoresistive element composed of two semiconductor thin film magnetoresistive element rows in which a large number of short-circuit electrodes are formed on a semiconductor thin film having a high electron mobility formed directly on an i substrate, The differential type semiconductor thin film magnetoresistive element is characterized in that the Si substrate has a groove formed in the thickness direction of the substrate so as to separate the two semiconductor thin film magnetoresistive element rows.

The invention according to claim 9 of the present invention is the same S
A differential type semiconductor thin film magnetoresistive element composed of two semiconductor thin film magnetoresistive element rows in which a large number of short-circuit electrodes are formed on a semiconductor thin film having a high electron mobility formed directly on an i substrate, The differential semiconductor thin film magnetoresistive element has a structure in which each Si substrate on which the two semiconductor thin film magnetoresistive element arrays are formed is divided.

In any of the first, second, fifth, and eighth aspects of the present invention, the parasitic sheet resistance of the Si substrate can be equivalently increased, whereby the current flowing through the substrate can be suppressed. . Further, in the inventions according to claims 3 and 4, the current flowing between the left and right semiconductor thin film magnetoresistive element rows can be suppressed by the reverse bias effect of the junction. Furthermore, in the invention described in claim 9, no current flows through the substrate between the left and right semiconductor thin film magnetoresistive element arrays.

In any of these, the parasitic resistance existing in the Si substrate, in other words, the conductivity is suppressed, so that the current flowing between the left and right semiconductor thin film magnetoresistive element rows can be suppressed, and therefore the electrical resistance can be reduced. It is possible to realize a differential type semiconductor thin film magnetoresistive element which has excellent cross-talk, excellent temperature characteristics of the midpoint voltage, excellent output sensitivity characteristics and high temperature durability.

(First Embodiment) FIG. 1 is a perspective view of a differential type semiconductor thin film magnetoresistive element according to a first embodiment of the present invention.

The figure shows a semiconductor thin film having a high electron mobility formed directly on the same single crystal Si substrate 1, specifically, two InSb thin films 2 on which a plurality of short-circuit electrodes 3 are formed. A differential semiconductor thin film magnetoresistive element 6 composed of semiconductor thin film magnetoresistive element rows 4 and 5 is shown. As a basic configuration of this element, in the extraction electrodes 7 to 10, the extraction electrodes 7 and 10 are input voltage terminals, 7 is a ground terminal, and 10 is a Vin terminal. The extraction electrodes 8 and 9 are common midpoint terminals and are commonly connected externally to serve as output terminals (midpoint terminals). Here, the behavior of the output terminal (midpoint terminal) at this time, that is, the temperature characteristic of the midpoint voltage is taken into consideration.

In the above structure, when the Si substrate 1 has a specific resistance of 100 Ω · cm and a substrate thickness of 500 μm, the sheet resistance is estimated to be 2 kΩ / □ at room temperature.
It is about. On the other hand, if the InSb thin film 2 used has a good crystallinity and is epitaxially grown on the Si substrate 1 with high orientation, the specific resistance at room temperature is about 6 mΩ.
cm and the film thickness are required to be 3 μm at which the electron mobility affecting the magnetic properties is saturated, and the sheet resistance is about 20 Ω / □. Therefore, the sheet resistance ratio of the Si substrate 1 and the InSb thin film 2 at room temperature is 1
It is about 00 times. The sheet resistance of the Si substrate 1 is shown in FIG.
The temperature dependence of the InSb thin film 2 is shown. As is clear from the figure, the temperature dependences of the sheet resistances of the InSb thin film and the Si substrate show different tendencies, and the sheet resistance is the most at -20 ° C. Ratio approaches, and approaches 50 times in the above example. At this level, the resistance of the InSb thin film magnetoresistive element is
The parasitic resistance of the board cannot be ignored. As a result, crosstalk occurs between the semiconductor thin film magnetoresistive element arrays 4 and 5, resulting in a phenomenon that the temperature characteristic of the midpoint voltage is largely deviated in the vicinity of −20 ° C. as shown in FIG.

On the other hand, the Si substrate 1 has a specific resistance of 1 k
The sheet resistance of the Si substrate 1 at room temperature is 1 by setting the Ω · cm or more and the thickness to 100 μm or less.
It becomes more than 00kΩ / □. In this case, the ratio with the InSb thin film 2 is 5000 times or more at room temperature and about 2500 times even at around −20 ° C., which is a sheet resistance ratio sufficient to avoid crosstalk. This state is shown in FIG. 3 described above. The deviation at -20 ° C is small. As is clear from the figure, the higher the specific resistance of the Si substrate and the thinner the Si substrate, the smaller this phenomenon becomes. In practice,
It is desired that the temperature fluctuation of the midpoint voltage is 10% or less of the output voltage in order to simplify the circuit processing when driving the semiconductor thin film magnetoresistive element in the circuit. Therefore, for example, when a voltage of 5 V is applied, the output voltage is practically 200 m
Although it can be about V _PP , in this case, it is necessary to accommodate the temperature fluctuation of the midpoint voltage of 20 mV or less. From FIG. 3, the Si substrate of the present embodiment, that is, the specific resistance of 1 kΩ · cm or more and the thickness of 100 μm or less By using the one, the temperature fluctuation of the midpoint voltage can be reduced. At this time, the conductivity type of the Si substrate 1 does not matter.

(Second Embodiment) FIG. 4 is a perspective view of a differential type semiconductor thin film magnetoresistive element according to a second embodiment of the present invention.

Since the structure of the differential type semiconductor thin film magnetoresistive element 6 itself is the same as that of the first embodiment, only the structure of the Si substrate 1 will be referred to here. As shown in the figure, the Si substrate 1 has an oxide layer 12 embedded in the Si substrate parallel to the substrate surface 11. As is well known, the oxide layer 12 is formed by a technique such as high-concentration oxygen doping of a Si substrate.
The oxide layer 1 is formed in a portion of several μm from the Si substrate surface 13.
2 is formed, if the specific resistance of the original Si substrate 1 is set to 1 kΩ · cm or more as in the first embodiment, the sheet resistance at room temperature is at least 10 ⁶ to 10 ⁷ Ω / □.
Therefore, the ratio with the specific resistance of the InSb thin film 2 is 4 to 5 digits, and it is possible to almost completely avoid the temperature fluctuation variation of the midpoint voltage. In the case of this configuration, even if the original specific resistance of the Si substrate 1 is about 100 Ω · cm, it is sufficient to suppress the variation in temperature fluctuation of the midpoint voltage. Further, the above oxide layer 1
2 is preferably provided as shallow as possible from the surface 13 of the Si substrate, and the larger the specific resistance of the Si substrate 1, the more preferable. The shallower the oxide layer 12 is, the more Si
The specific resistance of the substrate 1 may be small. In this case, S
The conductivity type of the i-substrate 1 does not matter.

(Third Embodiment) FIG. 5 is a perspective view of a differential type thin film magnetoresistive element according to a third embodiment of the present invention.

Here, like the above, only the structure of the Si substrate 1 will be referred to. As shown in the figure, in the Si substrate 1, the upper layer 14 parallel to the substrate surface is P type and the lower layer 15 is N type.
Type PN junction 16 in the substrate. Upper layer 14 is N
The lower layer 15 may be a P type. Further, the upper layer 14
Is preferably as thin as possible from this region within the range where carriers do not cause tunnel conduction to the lower layer 15.

When the differential semiconductor thin film magnetoresistive element 6 having the structure of the Si substrate 1 is used, for example, electrons are converted into Si.
In the case where the upper layer 14 is P-type and the lower layer 15 is N-type when flowing on the substrate surface, electrons flow in the P-type region of the upper layer 14 and flow into the N-type region of the lower layer 15 through the PN junction 16 as a forward characteristic. However, it is difficult to flow from the N-type region of the lower layer 15 through the PN junction 16 into the P-type region of the upper layer 14 after that due to the reverse direction characteristic. Will flow only to the upper layer 14. Even if the upper layer 14 is N-type and the lower layer 15 is P-type, the PN junction 1
The current flow in 6 basically always passes through the reverse junction portion, and as a result, the current flows only in the upper layer 14. Therefore, the sheet resistance of the upper layer 14 of the Si substrate 1 in contact with the InSb thin film 2 becomes a problem. The ratio of the sheet resistance of the upper layer 14 to the sheet resistance of the InSb thin film 2 is 5000 times or more at room temperature, which is a temperature characteristic of a midpoint voltage which is practically sufficient, as in the first embodiment.

(Fourth Embodiment) FIG. 6 is a perspective view of a differential type semiconductor thin film magnetoresistive element according to a fourth embodiment of the present invention.

As shown in the figure, in the Si substrate 1, the upper layer 17 parallel to the substrate surface is P type and the lower layer 18 is N type inside the substrate.
Type PN junction 19. Upper layer 17 is N type, lower layer 1
8 may be a P type. Further, a conduction type different from the conduction type of the upper layer 17 of the Si substrate 1 in which the differential type semiconductor thin film magnetoresistive element 6 composed of the two semiconductor thin film magnetoresistive element rows 4 and 5 is in direct contact, that is, in the present embodiment, Since the upper layer 17 is the P type, the N type buried layer 20 is formed in the direction perpendicular to the substrate surface so as to separate the two semiconductor thin film magnetoresistive element arrays 4 and 5. When the upper layer 17 is N-type,
The buried layer 20 becomes P-type. At this time, the buried layer 20
Preferably penetrates the lower layer 18, and the upper layer 17
Is preferably as thin as possible within the range where carriers do not cause tunnel conduction from this region.

When the differential type semiconductor thin film magnetoresistive element 6 having the structure of the Si substrate 1 is used, the buried layer 20 and the PN junction portion 19 against the flow of carriers from the semiconductor thin film magnetoresistive element array 4 to 5. As a result, a reverse-bonded state is always generated and the flow of carriers is blocked. Therefore, no current flows between the semiconductor thin film magnetoresistive element rows 4 and 5, and
Good temperature characteristics of the midpoint voltage can be obtained.

(Fifth Embodiment) FIG. 7 is a perspective view of a differential type semiconductor thin film magnetoresistive element according to a fifth embodiment of the present invention.

As shown in the figure, the semiconductor thin film magnetoresistive element arrays 4 and 5 of the Si substrate 1 are covered with a resist mask, and oxygen or nitrogen is doped by using, for example, an ion implantation method to form a semiconductor thin film. The regions 21 where the magnetoresistive element arrays 4 and 5 are not formed are oxidized or nitrided to increase the resistance. By using an ion implantation method or the like in regions where the semiconductor thin film magnetoresistive element arrays 4 and 5 are not formed on the raw Si substrate before forming the semiconductor thin film magnetoresistive element arrays 4 and 5, oxygen or
It may be doped with nitrogen. At this time, the oxidized or nitrided region 21 is preferably oxidized or nitrided deeply in the substrate. Further, the original Si substrate 1 having the highest specific resistance and the substrate thickness as thin as possible are used. When such a Si substrate 1 is used, the substrate region 22 through which a current flows becomes narrower, and as a result, it becomes difficult for a current to flow between the semiconductor thin film magnetoresistive element arrays 4 and 5, and crosstalk can be reduced. The temperature characteristic of the point voltage can be improved.

(Sixth Embodiment) FIG. 8 is a perspective view of a differential type semiconductor thin film magnetoresistive element according to a sixth embodiment of the present invention.

As shown in the figure, the semiconductor thin film magnetoresistive element arrays 4 and 5 of the Si substrate 1 are covered with a resist mask,
The region 23 of the Si substrate 1 in which the semiconductor thin film magnetoresistive element arrays 4 and 5 are not formed is anodized by immersing in a chemical solution and passing a chemical current. At this time, it is necessary to cover the resist mask at least slightly wider than the formation width of the semiconductor thin film magnetoresistive element arrays 4 and 5. If this is not done, the sidewalls of the semiconductor thin film magnetoresistive element arrays 4 and 5 are exposed, so that oxidative corrosion occurs during anodization. Also in this case, as in the case of the fifth embodiment, the thicker the anodic oxide film is, the more preferable it is, and the resistivity of the Si substrate 1 is preferably as large as possible and the substrate thickness is preferably as thin as possible. By using such a Si substrate 1, crosstalk can be reduced and the temperature characteristic of the midpoint voltage can be improved for the same reason as in the fifth embodiment.

(Embodiment 7) FIG. 9 is a perspective view of a differential type semiconductor thin film magnetoresistive element according to a seventh embodiment of the present invention.

As shown in the figure, the semiconductor thin film magnetoresistive element arrays 4 and 5 of the Si substrate 1 are covered with a resist mask and the semiconductor thin film magnetoresistive element arrays 4 and 5 are formed by using oxygen plasma or nitrogen plasma. Area 24 not formed
The surface of is oxidized or nitrided to increase the resistance. On this occasion,
The oxidized or nitrided region 24 is preferably oxidized or nitrided deeply in the substrate. In addition, the original Si
A substrate having a resistivity as high as possible and a substrate having a thickness as thin as possible are used. When such a Si substrate 1 is used, the substrate region 22 through which a current flows becomes narrower, and as a result, it becomes difficult for a current to flow between the semiconductor thin film magnetoresistive element arrays 4 and 5, and crosstalk can be reduced. The temperature characteristic of the point voltage can be improved.

(Embodiment 8) FIG. 10 shows the eighth embodiment of the present invention.
3 is a perspective view of the differential semiconductor thin film magnetoresistive element of the embodiment of FIG.

As shown in the figure, an Si substrate 1 having a groove 25 formed in the thickness direction of the substrate so as to separate the semiconductor thin film magnetoresistive element arrays 4 and 5 is used. The separation groove 25 can be easily formed by half-cutting with a dicing blade. Of course, a plurality of the grooves 25 may be provided between the semiconductor thin film magnetoresistive elements 4 and 5. Furthermore, the deeper the engraving depth, the larger the specific resistance of the Si substrate 1, and the thinner the substrate thickness, the more preferable. By doing so, the current flowing through the inside of the Si substrate 1 between the semiconductor thin film magnetoresistive elements 4 and 5 can be suppressed. This is of course because the resistance of the Si substrate is equivalently increased. This also makes it possible to improve the temperature characteristics of the midpoint voltage.

(Embodiment 9) FIG. 11 shows a ninth embodiment of the present invention.
3 is a perspective view of the differential semiconductor thin film magnetoresistive element of the embodiment of FIG.

As shown in the figure, after the semiconductor thin film magnetoresistive element arrays 4 and 5 are formed on the same Si substrate 1, the semiconductor thin film magnetoresistive element arrays 4 and 5 are diced between them. The differential type semiconductor thin film magnetoresistive element 6 has a structure in which the both are connected by an external terminal with a gap 26 therebetween. In this configuration, as a matter of course, the current flow through the Si substrate in the semiconductor thin film magnetoresistive element arrays 4 and 5 can be completely cut off, and further, with respect to the specific resistance and the thickness of the Si substrate 1, However, the specific resistance can be made smaller than that in the above-described embodiments and the like, and the substrate thickness can be made thick so that the resistances of the individual semiconductor thin film magnetoresistive element arrays 4 and 5 are not affected. Further, in the case of this configuration, the center-to-center distance 27 between the semiconductor thin film magnetoresistive element rows 4 and 5 can be arbitrarily set, and when used as a rotation sensor, it can be arbitrarily adjusted to the pitch of the detected gear rotor at low cost. it can.

[0054]

As described above, according to the present invention, a differential semiconductor thin film magnetoresistive element having a structure in which an InSb epitaxially grown thin film having excellent output sensitivity characteristics and high temperature durability is directly formed on a Si wafer substrate. , It is possible to reduce the electrical crosstalk between the left and right semiconductor thin film magnetoresistive element arrays caused by the current flowing through the substrate due to the conductivity of the Si substrate, and to realize good temperature characteristics of the midpoint voltage, Its industrial utility value is extremely high.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a differential semiconductor thin film magnetoresistive element according to a first embodiment of the present invention.

FIG. 2 is a diagram showing temperature dependence of sheet resistance of a Si substrate and an InSb thin film.

FIG. 3 is a diagram for explaining a temperature characteristic of a midpoint voltage.

FIG. 4 is a perspective view showing a differential type semiconductor thin film magnetoresistive element according to a second embodiment of the present invention.

FIG. 5 is a perspective view showing a differential semiconductor thin film magnetoresistive element according to a third embodiment of the present invention.

FIG. 6 is a perspective view showing a differential semiconductor thin film magnetoresistive element according to a fourth embodiment of the present invention.

FIG. 7 is a perspective view showing a differential semiconductor thin film magnetoresistive element according to a fifth embodiment of the present invention.

FIG. 8 is a perspective view showing a differential semiconductor thin film magnetoresistive element according to a sixth embodiment of the present invention.

FIG. 9 is a perspective view showing a differential type semiconductor thin film magnetoresistive element according to a seventh embodiment of the present invention.

FIG. 10 is a perspective view showing a differential semiconductor thin film magnetoresistive element according to an eighth embodiment of the present invention.

FIG. 11 is a perspective view showing a differential type semiconductor thin film magnetoresistive element according to a ninth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Si substrate 2 InSb thin film 3 Short circuit electrode 4, 5 Semiconductor thin film magnetoresistive element array 6 Differential type semiconductor thin film magnetoresistive element 7-10 Extraction electrode 12 Oxide layer 14, 17 Upper layer 15, 18 Lower layer 16, 19 PN junction part 20 Buried layer 21 Oxygen or nitrogen doped layer 22 Current flowing substrate region 23 Anodizing region 24 Plasma oxidation or nitriding region 25 Separation groove 26 Dividing gap 27 Center distance

Front page continuation (72) Hideyuki Tanigawa, 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Akira Matsuura, 1006, Kadoma, Kadoma City, Osaka (72) Invention Satoshi Ouchi 1006, Kadoma, Kadoma-shi, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (9)

[Claims] 1. A differential type semiconductor thin film magnetic composed of two semiconductor thin film magnetoresistive element arrays in which a large number of short-circuit electrodes are formed on a semiconductor thin film having a high electron mobility formed directly on the same Si substrate. A resistance element, the Si substrate having a specific resistance of 1 kΩ · cm or more and a thickness of 100 μm
A differential semiconductor thin film magnetoresistive element characterized by the following. 2. A differential semiconductor thin film magnetic composed of two semiconductor thin film magnetoresistive element arrays in which a large number of short-circuit electrodes are formed on a semiconductor thin film having a high electron mobility formed directly on the same Si substrate. It is a resistance element, and the Si substrate is
A differential semiconductor thin film magnetoresistive element having a Si oxide layer embedded in the substrate and parallel to the surface of the substrate. 3. A differential semiconductor thin film magnetic composed of two semiconductor thin film magnetoresistive element arrays in which a large number of short-circuit electrodes are formed on a semiconductor thin film having a high electron mobility formed directly on the same Si substrate. A differential semiconductor thin film magnetoresistive element, wherein the Si substrate has a PN junction in parallel with the substrate surface inside the substrate. 4. A differential semiconductor thin film magnetic composed of two semiconductor thin film magnetoresistive element arrays in which a large number of short-circuit electrodes are formed on a semiconductor thin film having high electron mobility formed directly on the same Si substrate. In the resistance element, the Si substrate has a PN junction portion in parallel with the substrate surface inside the substrate, and an embedded layer having a polarity different from the conductivity type of the Si substrate portion in direct contact with the semiconductor thin film is used for the two semiconductor thin films. A differential semiconductor thin film magnetoresistive element, characterized in that it is formed in a direction perpendicular to a substrate surface so as to separate the magnetoresistive element rows. 5. A differential semiconductor thin film magnetic composed of two semiconductor thin film magnetoresistive element arrays in which a large number of short-circuit electrodes are formed on a semiconductor thin film having high electron mobility formed directly on the same Si substrate. A differential semiconductor thin film magnetoresistive element, which is a resistive element, wherein a region of the Si substrate on which a semiconductor thin film is not formed is doped with oxygen or nitrogen. 6. A differential type semiconductor thin film magnetic composed of two semiconductor thin film magnetoresistive element arrays in which a large number of short-circuit electrodes are formed on a semiconductor thin film having a high electron mobility formed directly on the same Si substrate. A differential semiconductor thin-film magnetoresistive element, which is a resistive element, wherein a region of the Si substrate on which a semiconductor thin film is not formed is anodized. 7. A differential semiconductor thin film magnetic composed of two semiconductor thin film magnetoresistive element arrays in which a large number of short-circuit electrodes are formed on a semiconductor thin film having high electron mobility formed directly on the same Si substrate. A region which is a resistance element and in which the semiconductor thin film is not formed on the Si substrate is subjected to plasma treatment,
A differential type semiconductor thin film magnetoresistive element characterized in that its surface is oxidized or nitrided. 8. A differential type semiconductor thin film magnetic composed of two semiconductor thin film magnetoresistive element arrays in which a large number of short-circuit electrodes are formed on a semiconductor thin film having a high electron mobility formed directly on the same Si substrate. A differential semiconductor thin film magnetoresistive element, wherein the Si substrate has a groove formed in the thickness direction of the substrate so as to separate the two semiconductor thin film magnetoresistive element rows. 9. A differential type semiconductor thin film magnetic composed of two semiconductor thin film magnetoresistive element arrays in which a large number of short-circuit electrodes are formed on a semiconductor thin film having high electron mobility formed directly on the same Si substrate. A differential semiconductor thin film magnetoresistive element, which is a resistive element and has a configuration in which each Si substrate on which the two semiconductor thin film magnetoresistive element rows are formed is divided.