JP2004257995A - 3-dimensional magnetism sensing device and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To adjust the gap of the detection sensitivity caused by the use of magnetic flux convergence board at the time of the detection of the magnetic field in the horizontal direction and in the vertical direction, and to improve the S/N ratio in the detection of the magnetic field in the vertical direction. <P>SOLUTION: The magnetic sensing elements X1 to X4 are used to detect the magnetic field strength in the X direction in the horizontal magnetic field, and the magnetic sensing elements Y1 to Y4 are used to detect the magnetic field strength in the Y direction. The magnetic sensing elements Z1-Z8 are also arranged to the end area of the magnetic flux convergence board FC. With respect to the vertical magnet field components, the magnetic sensing elements Xi, Yi and Zi detect respectively the magnetic field strength with the same incident angle, so that the total output corresponding to the vertical magnetic field strength is obtained by adding the outputs from all the magnet sensing elements. Here, it is assumed that (the sum total of all sensing elements) ≥ ä(the magnetic amplification factor of the above-mentioned magnetic flux convergence board to the magnetic field in the horizontal plane of the above-mentioned substrate)×(the number of the magnetic sensing elements per pair)} -1. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a three-dimensional magnetic detection device and a semiconductor device equipped with the three-dimensional magnetic detection device.
[0002]
More specifically, the present invention relates to a three-dimensional magnetic detecting device having a magnetic converging plate and a plurality of magnetic detecting elements formed on a substrate, which is suitable for detecting terrestrial magnetism, and a three-dimensional magnetic detecting device. The present invention relates to a mounted semiconductor device.
[0003]
[Prior art]
Conventionally, as a magnetic sensor, a Hall element using the Hall effect, a magnetoresistive element, a Hall IC combining these elements with an IC, a flux gate, and the like are known.
[0004]
Further, a method of three-dimensionally detecting geomagnetism by applying such a magnetic sensor and a signal processing method thereof are disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2002-196055). This Patent Document 1 discloses a “three-axis magnetic sensor, an omnidirectional magnetic sensor, and an azimuth measuring method using the same”, in which a substrate is formed as a main body, and the magnetic field is defined in a plane parallel to the substrate. A hybrid including a fluxgate magnetic sensor for detecting a biaxial component of a vector, a Hall element for detecting a component of a magnetic vector in a direction perpendicular to the substrate, an inclination sensor for detecting an inclination angle of the substrate, and a CPU; A hybrid magnetic sensor integrally configured as an IC is described.
[0005]
Further, Patent Document 2 (Japanese Patent Application Laid-Open No. 2002-71381) discloses, as a magnetic field direction detection sensor capable of determining the direction of a magnetic field in three dimensions, one magnetic field concentrator having a flat shape and at least a first magnetic field concentrator. And a second Hall effect element, or at least a first group and a second group of Hall effect elements, wherein the Hall effect element is arranged in an end region of the magnetic field concentrator. Have been.
[0006]
[Patent Document 1]
JP-A-2002-196055 (page 1, FIG. 3)
[0007]
[Patent Document 2]
JP-A-2002-71381 (page 1, FIG. 1)
[0008]
[Problems to be solved by the invention]
As described above, Patent Document 1 discloses an invention that detects a three-dimensional magnetic field by a so-called hybrid configuration in which a flux gate sensor and a Hall element are separately arranged on a substrate. However, in the invention disclosed in Patent Document 1, since the sensor and the signal processing circuit are arranged in a hybrid configuration, there is an inevitable problem that the mounting area increases. Particularly in recent years, a position information system in which a three-dimensional terrestrial magnetism sensor is mounted on a mobile terminal and displays the orientation of the map in accordance with the orientation of the mobile terminal has been put into practical use. In systems that are very limited, the sensors need to be smaller.
[0009]
Further, in Patent Document 2, a plurality of Hall elements are arranged on an end face of a magnetic converging plate to detect an angle of a magnetic field in a horizontal direction, and a Hall element is arranged to simultaneously detect a magnetic field in a vertical direction. A magnetic sensor is disclosed. According to Patent Document 2, with respect to the magnetic field in the horizontal direction, the magnetic flux concentrator amplifies the magnetic flux density, so that the magnetic field sensitivity is improved and the S / N ratio (signal / noise) ratio is also improved. In particular, in order to detect a very small magnetic field (30 μT) such as terrestrial magnetism, the improvement of the S / N ratio is an important factor. However, if the length is sufficiently large relative to its thickness, the magnetic flux concentrator has almost no effect of amplifying the magnetic flux density with respect to the magnetic field in the vertical direction. It is an unavoidable problem that the S / N ratio becomes worse as compared with the horizontal direction. That is, since the magnetic detection sensitivity differs depending on the direction, calibration is always required, and in addition, the resolution of measurement is reduced because the S / N ratio in the vertical direction cannot be improved. .
[0010]
In view of the above, it is therefore an object of the present invention to eliminate a deviation in detection sensitivity caused by using a magnetic converging plate when detecting a magnetic field in a horizontal direction and a vertical direction, and to detect a magnetic field in a vertical direction. It is an object of the present invention to provide a three-dimensional magnetic detection device and a semiconductor device having an improved S / N ratio with respect to the above.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the present invention according to claim 1 is a three-dimensional magnetic detection device having a magnetic converging plate and a plurality of magnetic detecting elements formed on a substrate, wherein an end of the magnetic converging plate is provided. When arranging at least two pairs of magnetic detection elements in close proximity to the partial area and sequentially or simultaneously obtaining magnetic detection signals from the magnetic detection elements included in each magnetic detection element pair,
Total number of all magnetic sensing elements ≧ {(magnetic amplification factor of the magnetic converging plate with respect to a magnetic field in a plane direction parallel to the substrate) × (number of magnetic sensing elements per pair)} − 1
It is configured to satisfy certain conditions.
[0012]
According to a second aspect of the present invention, in the three-dimensional magnetic detection device according to the first aspect, (the number of magnetic detection elements included in a pair of magnetic detection elements) × (the magnetic field in a plane direction parallel to the substrate). The number of magnetic detection elements closest to the value of the magnetic amplification factor of the magnetic flux concentrator or the integer number or more is selected, and the magnetic field strength in the direction perpendicular to the substrate is detected using the selected magnetic detection elements.
[0013]
According to a third aspect of the present invention, in the three-dimensional magnetic detection device according to the first aspect, an X-direction component and a Y-direction component horizontal to the substrate are detected by using the at least two pairs of magnetic detection elements, Further, a Z-direction component perpendicular to the substrate is detected by providing a magnetic detecting element provided in addition to the at least two pairs of magnetic detecting elements.
[0014]
According to a fourth aspect of the present invention, in the three-dimensional magnetic detection device according to any one of the first to third aspects, the magnetic detection element is a Hall element formed on a silicon substrate.
[0015]
According to a fifth aspect of the present invention, in the three-dimensional magnetic detection device according to any one of the first to third aspects, all of the magnetic detection elements or some of the magnetic detection elements are formed of a compound semiconductor. I do.
[0016]
The present invention according to claim 6 is a three-dimensional magnetic detecting device having a plurality of magnetic detecting elements formed on a substrate, wherein at least two pairs of magnetic detecting elements detecting components in two directions horizontal to the substrate. Is disposed close to an end region of the first magnetic converging plate, and separately from the at least two pairs of magnetic detecting elements, a magnetic detecting element for detecting a magnetic field intensity in a direction perpendicular to the substrate is provided. And a second magnetic flux concentrator provided near the upper part of the magnetic sensing element.
[0017]
According to a seventh aspect of the present invention, in the three-dimensional magnetic detection device according to the sixth aspect, the length is defined by (the length of the second magnetic focusing plate) / (the thickness of the second magnetic focusing plate). The aspect ratio is 3 or less.
[0018]
The present invention according to claim 8 is the three-dimensional magnetic detection device according to claim 6 or 7, wherein the magnetic detection element is a Hall element formed on a silicon substrate.
[0019]
According to a ninth aspect of the present invention, in the three-dimensional magnetic detection device according to the sixth or seventh aspect, all of the magnetic detection elements or some of the magnetic detection elements are formed of a compound semiconductor.
[0020]
The present invention according to claim 10 is a three-dimensional magnetic detecting device having a plurality of magnetic detecting elements formed on a substrate, wherein at least two pairs of magnetic detecting elements detecting components in two directions horizontal to the substrate. Is arranged in close proximity to the end region of the magnetic flux concentrator, and separately from the at least two pairs of magnetic detection elements, is formed of a compound semiconductor for detecting a magnetic field intensity in a direction perpendicular to the substrate. The magnetic detection element is placed.
[0021]
According to an eleventh aspect of the present invention, in the three-dimensional magnetic detection device according to the tenth aspect, a magnetic detection element other than a magnetic detection element that detects a magnetic field intensity in a direction perpendicular to the substrate is formed on a silicon substrate. This is a Hall element that has been manufactured.
[0022]
According to a twelfth aspect of the present invention, in the three-dimensional magnetic detection device according to any one of the first to eleventh aspects, a magnetic detection signal sequentially or simultaneously output from the magnetic detection element is input, and A signal processing circuit for performing predetermined signal processing or data processing is provided.
[0023]
According to a thirteenth aspect of the present invention, in the three-dimensional magnetic detection device according to the twelfth aspect, the signal processing circuit is formed on the same substrate on which the magnetic detection element is formed.
[0024]
According to a fourteenth aspect of the present invention, there is provided a semiconductor device in which the three-dimensional magnetic detection device according to any one of the first to thirteenth aspects is formed on a semiconductor substrate.
[0025]
According to a fifteenth aspect of the present invention, in the semiconductor device having the three-dimensional magnetic detection device according to the fifth aspect, the compound semiconductor is formed on a separate substrate.
[0026]
According to a sixteenth aspect of the present invention, in the semiconductor device having the three-dimensional magnetic detection device according to the ninth aspect, the compound semiconductor is formed on a separate substrate.
[0027]
According to a seventeenth aspect of the present invention, in the semiconductor device having the three-dimensional magnetic detection device according to the tenth aspect, the compound semiconductor is formed on a separate substrate.
[0028]
According to an eighteenth aspect of the present invention, in the semiconductor device having the three-dimensional magnetic detection device according to the twelfth aspect, the signal processing circuit is formed on a substrate separate from the magnetic detection element.
[0029]
According to a nineteenth aspect of the present invention, in the three-dimensional magnetic detection device according to any one of the first to thirteenth aspects, geomagnetism is detected using the magnetic detection element.
[0030]
According to a twentieth aspect of the present invention, in the semiconductor device according to any one of the fourteenth to eighteenth aspects, the magnetism is detected by using the magnetic detection element.
[0031]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, each embodiment will be described in detail with reference to the drawings.
[0032]
Embodiment 1
FIG. 1 is a plan view showing an example of a three-dimensional magnetic sensor to which the present invention is applied. FIG. 2 is a sectional configuration diagram of the three-dimensional magnetic sensor shown in FIG.
[0033]
As shown in FIGS. 1 and 2, the magnetic sensing elements (Hall elements) X1 to X4, Y1 to Y4, and Z1 to Z8 formed on a semiconductor substrate (not shown) are formed by a circular magnetic converging plate FC. It is located in the end area.
[0034]
Here, X1 to X4 indicate magnetic detecting elements (Hall elements) for detecting a magnetic field in the X direction in the horizontal magnetic field, and Y1 to Y4 indicate magnetic detecting elements (Hall elements) for detecting a magnetic field in the Y direction. Apart from these magnetic detecting elements X1 to X4 and Y1 to Y4, magnetic detecting elements Z1 to Z8 are similarly arranged in an end region of the magnetic converging plate FC. In the magnetic sensor having such a configuration, when the angle of the horizontal magnetic field is detected, as shown in FIG. 2, the directions of the converged and vertically converted magnetic fields are opposite to each other. Therefore, if the outputs (= X3 + X4) of the magnetic detection elements X3 and X4 are subtracted from the outputs (= X1 + X2) of the magnetic detection elements X1 and X2 (that is, (X1 + X2) − (X3 + X4)), An output corresponding to the approach angle is obtained. Specifically, a signal proportional to the cosine (cos) of the entry angle of the magnetic field is obtained. Similarly, in the Y direction, a signal proportional to the sine (sin) of the entry angle of the magnetic field is obtained.
[0035]
On the other hand, with respect to the vertical magnetic field component, the magnetic field enters each magnetic detection element from the same direction, so that an output corresponding to the vertical magnetic field intensity can be obtained by adding the outputs of all the magnetic detection elements. These outputs are subjected to signal processing such as amplification using an operational amplifier at the subsequent stage and conversion into angle information.
[0036]
It has been experimentally confirmed that such a magnetic sensor can be used to detect a terrestrial-level minute magnetic field, and the actual measurement results are shown in FIG.
[0037]
FIG. 4 is a circuit diagram for processing detection signals from the magnetic detection elements (Hall elements) X1 to X4, Y1 to Y4, and Z1 to Z8 shown in FIG. As shown in the figure, detection signals from the respective magnetic detection elements are input to the sensor switching circuit 20, and in response to output selection signals (1), (2), and (3), respective sensor outputs X1 to X4. , Y1 to Y4, Z1 to Z8 are selectively transmitted. In the arithmetic circuit 30 incorporating these sensor outputs, the operation for obtaining the X-direction component, the operation for obtaining the Y-direction component, and the Z-direction in accordance with the output selection signals (1), (2), and (3). Perform an operation to obtain the component.
[0038]
That is, to obtain the X-direction component according to the output selection signal (1),
{(X1 + X2)-(X3 + X4)} · Am
Is performed. Here, Am is the magnetic amplification factor of the magnetic flux concentrator FC.
[0039]
Similarly, to obtain a Y-direction component according to the output selection signal (2),
{(Y1 + Y2)-(Y3 + Y4)} · Am
Is performed.
[0040]
In order to obtain the Z-direction component according to the output selection signal (3),
(X1 + X2 + X3 + X4) + (Y1 + Y2 + Y3 + Y4) + (Z1 + Z2 + Z3 + Z4 + Z5 + Z6 + Z7 + Z8)
Is performed.
[0041]
Thereafter, the X-direction component signal, the Y-direction component signal, and the Z-direction component signal output from the arithmetic circuit 30 are output to the outside via the output switch 40. At the subsequent stage of the output switch 40, a microprocessor, other control circuits, and the like can be connected via, for example, an A / D converter.
[0042]
Returning to FIG. 1 again, the description will be made. It is now assumed that the magnetic amplification factor Am of the magnetic flux concentrator FC is 4. If the magnetic sensitivity per magnetic detection element (Hall element) is K and the horizontal magnetic field strength is Bh, the sensor output obtained from the magnetic field in the X direction is 4 × (4K) × Bh × cos α = 16BhKcos α (Α: angle of entry of the magnetic field). Similarly, an output of 16 BhK sin α is obtained from the magnetic field in the Y direction.
[0043]
Here, when a vertical magnetic field component is obtained by superimposing a total of 16 element outputs arranged near the end region of the magnetic flux concentrator FC, the sensor output in the vertical (= Z) direction is (16K) × Bv (Bv: vertical magnetic field intensity). Therefore, the detection sensitivities in the X, Y, and Z directions are all 16K, and the detection sensitivities are the same in each of the X, Y, and Z directions.
[0044]
Next, regarding the S / N ratio, since the magnetic amplification factor is 4 in the X and Y directions by the magnetic converging plate FC, the S / N ratio is improved to four times. On the other hand, although there is no such magnetic amplification effect in the Z direction, the number of elements used for signal detection is four times as large as that in the X and Y directions (that is, 16), so that the noise level is 1 /. √4 = １ ／, and S / N is doubled.
[0045]
In the example described above, the case where the magnetic gain of the magnetic converging plate FC is an integer of "4" is assumed. However, if the gain of the magnetic converging plate FC includes a small number such as 4.1, for example, Is 16.4 BhK cos α, and the detection output in the Y direction is 16.4 BhK sin α.
[0046]
Here, as the number of elements for detecting the magnetic field strength in the Z direction,
Total number of all magnetic detecting elements ≧ {(magnetic amplification factor of magnetic converging plate with respect to magnetic field in a plane direction parallel to the substrate on which the magnetic detecting elements are formed) × (number of magnetic detecting elements per pair)} − 1
Consider that elements are arranged in a number that satisfies the following inequality. Now, assuming that the amplification factor of the magnetic flux concentrator FC is 4.1, the number of magnetic detection elements included in each pair is four.
Total number of elements to be arranged ≧ 4.1 × 4-1 = 15.4
Thus, at least 16 elements are arranged. When 16 magnetic detecting elements are arranged as in this example, the factor (detection sensitivity) of the amplification factor in the X, Y, and Z directions is 16.4: 16.4: 16 = 1.025: 1.025. : 1, it can be seen that they are almost the same. As for the S / N ratio, the S / N in the Z direction is improved by a factor of two, as in the previous example.
[0047]
As described above, by selecting the number of magnetic detection elements for detecting the magnetic field in the Z direction in correlation with the magnetic amplification factor of the magnetic flux concentrator FC, the S / N ratio can be improved while the detection sensitivity in the X, Y, and Z directions is uniform. It is possible to improve the ratio.
[0048]
Although an example in which a circular magnetic converging plate is used has been described, similar effects can be obtained with a cross-shaped magnetic converging plate as shown in FIG. However, in this case, it is necessary to arrange the magnetic detection element at a position where the magnetic convergence effect can be obtained. Thus, it is possible to configure the three-dimensional magnetic sensor according to the present embodiment without depending on the shape of the magnetic converging plate. Further, as shown in FIG. 5B, the element for detecting the magnetic field in the Z direction does not need to be arranged in the end region of the magnetic converging plate. The effect of is obtained.
[0049]
further,
Total number of all magnetic detecting elements ≧ {(magnetic amplification factor of magnetic converging plate with respect to magnetic field in a plane direction parallel to the substrate on which the magnetic detecting elements are formed) × (number of magnetic detecting elements per pair)} − 1
As long as the inequality is satisfied, the element for detecting the magnetic field in the Z direction does not need to be separately provided as an independent magnetic detection element, and it is possible to use a magnetic detection element for detecting the magnetic fields in X and directions. is there.
[0050]
Embodiment 2
FIG. 6 is a plan view showing a three-dimensional magnetic sensor according to another embodiment. In this embodiment, magnetic detection elements (Hall elements) X1a, X1b, X2a, X2b, Y1a, Y1b, Y2a, Y2b formed on a semiconductor substrate are arranged in an end region of a circular magnetic converging plate FC1. ing. Here, the magnetic detecting elements X1a, X1b, X2a, X2b detect the magnetic field in the X direction in the horizontal magnetic field, and the magnetic detecting elements Y1a, Y1b, Y2a, Y2b detect the magnetic field in the Y direction. In the present embodiment, separately from these magnetic detecting elements, magnetic detecting elements Z1 to Z4 for detecting a magnetic field in the Z direction are provided, and a second magnetic converging plate FC2 is locally attached above these elements. It is.
[0051]
Then, by appropriately selecting the aspect ratio (= length / thickness) of the second magnetic focusing plate FC2, it is possible to have a magnetic focusing effect in the Z direction.
[0052]
FIG. 7 is a circuit diagram for processing detection signals from the magnetic detection elements (Hall elements) X1a, X1b, X2a, X2b, Y1a, Y1b, Y2a, Y2b, Z1 to Z4 shown in FIG. As shown in the figure, detection signals from the respective magnetic detection elements are input to a sensor switching circuit 20 ', and in response to output selection signals (1), (2), and (3), three types of sensor outputs X1a. , X1b, X2a, X2b, sensor outputs Y1a, Y1b, Y2a, Y2b, and sensor outputs Z1 to Z4 are selectively transmitted. In the arithmetic circuit 30 'incorporating these sensor outputs, an operation for obtaining an X-direction component, an operation for obtaining a Y-direction component, and a Z operation in accordance with the output selection signals (1), (2), and (3). An operation for obtaining a direction component is performed.
[0053]
That is, to obtain the X-direction component according to the output selection signal (1),
{(X1a + X1b)-(X2a + X2b)} · Am1
Is performed. Here, Am1 is a horizontal magnetic amplification factor of the magnetic converging plate FC1.
[0054]
Similarly, to obtain a Y-direction component according to the output selection signal (2),
{(Y1a + Y1b)-(Y2a + Y2b)} · Am1
Is performed. As described above, Am1 is the horizontal magnetic amplification factor of the magnetic converging plate FC1.
[0055]
In order to obtain the Z-direction component according to the output selection signal (3),
(X1a + X1b + X2a + X2b) + (Y1a + Y1b + Y2a + Y2b) + {(Z1 + Z2 + Z3 + Z4)} · Am2
Is performed. Here, Am2 is the magnetic amplification factor in the vertical direction of the second magnetic converging plate FC2.
[0056]
FIG. 8 shows an analysis result by a magnetic simulation. The magnetic flux concentrator assumed in this simulation is a soft magnetic material having a magnetic permeability of 1400, and has a thickness of about 23 microns. The analysis method is the integral element method. The simulation results indicate that the smaller the aspect ratio, which is the length / thickness of the second magnetic flux concentrator FC2, the larger the magnetic amplification factor in the Z direction. As is apparent from the figure, the aspect ratio of the length / thickness of the second magnetic flux concentrator FC2 is desirably 3 or less.
[0057]
Thus, by giving the magnetic amplification effect in the Z direction as well as in the X and Y directions, it is possible to improve the S / N in the Z direction, and to improve the angle detection resolution in the three-dimensional magnetic sensor. Connect.
[0058]
In addition, in order to improve the thickness of the second magnetic flux concentrator FC2, for example, a method of stacking the magnetic flux concentrators on a stack may be adopted.
[0059]
Embodiment 3
FIG. 9 is a plan view showing a three-dimensional magnetic sensor according to the third embodiment. In this embodiment, magnetic detection elements (Hall elements) X1, X2, Y1, and Y2 formed on a semiconductor substrate are arranged in an end region of a circular magnetic flux concentrator FC. Here, the magnetic detection elements X1 and X2 detect a magnetic field in the X direction in the horizontal magnetic field, and the magnetic detection elements Y1 and Y2 detect a magnetic field in the Y direction. Apart from these magnetic detecting elements X1, X2, Y1 and Y2, magnetic detecting elements ZZ1 to ZZ4 for detecting a magnetic field in the Z direction are arranged, and these magnetic detecting elements are formed of a compound semiconductor.
[0060]
【Example】
FIG. 10A is a cross-sectional view showing one embodiment of a hybrid magnetic sensor to which the present invention is applied. As shown in the figure, a second substrate 6 on which a compound semiconductor element 8 is formed is disposed above a first substrate 2 on which an integrated circuit portion 4 is formed. Magnetic converging plates 14 and 16 are formed on 6 via adhesive layers 10 and 12. In addition, predetermined electrodes are electrically connected to the compound semiconductor element 8 and the integrated circuit portion 4 by wire bonding or the like.
[0061]
FIG. 10B is a cross-sectional view illustrating a hybrid magnetic sensor according to another embodiment. As shown in the figure, a second substrate 6 on which a magnetic converging plate 14 formed by laminating a compound semiconductor element 8 and an adhesive layer 10 via an adhesive layer 10 is disposed so as to face the integrated circuit portion 4, and The electrode 8 and the electrode of the integrated circuit part 4 are connected via conductive bumps 20.
[0062]
As the first substrate 2 on which the integrated circuit portion 4 is formed, it is preferable to use a Si substrate, a sapphire substrate, a GaAs substrate, or the like.
[0063]
(Example 1)
Non-doped InSb was grown to a thickness of 1 μm on a GaAs substrate by MBE. The film characteristics of the InSb thin film are such that the electron mobility is 40,000 cm.²/ Vs. Next, the InSb thin film was processed by a photolithography method into a Hall element having a cross shape as a basic shape, thereby forming a sensor portion. Next, a magnetic converging plate having a desired shape was attached on the sensor unit via an insulating layer. Next, the substrate was diced for each sensor unit to produce a sensor chip.
[0064]
On the other hand, an integrated circuit was formed on a Si substrate by a CMOS process. After forming a protective film on the integrated circuit, a window was opened in an electrode portion. Next, the sensor chip was die-bonded on the protective film, and the electrodes of the sensor chip and the electrodes of the integrated circuit were connected by wire bonding.
[0065]
The integrated circuit board to which the sensor chip was connected was plastic-molded into one package to complete a hybrid magnetic sensor as shown in FIG.
[0066]
The hybrid magnetic sensor of this embodiment has a very high sensitivity of 2 V / Gauss for both the horizontal and vertical magnetic fields including the signal amplification by the integrated circuit. Further, the S / N ratio was improved by a factor of 10 as compared with the case where a similar sensor was prototyped using a silicon Hall element, and the azimuth measurement resolution was improved from 6 degrees to 0.6 degrees.
[0067]
(Example 2)
1nm SiO on Si substrate₂Was formed by chemical treatment, the substrate was placed in an MBE chamber, and the substrate was grown at room temperature at a temperature of 1 nm. Thereafter, the substrate temperature is raised to 850 ° C., annealing is performed for 30 minutes, and γ-Al₂O₃Was formed to about 1 nm. Further, a 1 μm thin film of doped InSb was grown thereon. The film characteristics of the InSb thin film are such that the electron mobility is 35,000 cm.²/ Vs. Next, the InSb thin film was processed by a photolithography method into a Hall element having a cross shape as a basic shape, thereby forming a sensor portion. Next, a magnetic converging plate having a desired shape was attached on the sensor unit via an insulating layer. Next, the substrate was diced for each sensor unit to produce a sensor chip.
[0068]
On the other hand, an integrated circuit was formed on a Si substrate by a CMOS process. After forming a protective film on the integrated circuit, a window was opened in an electrode portion. Next, conductive bumps were formed in the window opening portions, and the sensor chip was connected thereto by flip-chip bonding, followed by plastic molding to complete a hybrid magnetic sensor as shown in FIG.
[0069]
The hybrid magnetic sensor of this embodiment has a very high sensitivity of 2 V / Gauss for both the horizontal and vertical magnetic fields including the signal amplification by the integrated circuit. In addition, the S / N ratio was improved eight times as compared with the case where a similar sensor was fabricated using a silicon Hall element, and the azimuth measurement resolution was improved from 6 degrees to 0.8 degrees.
[0070]
As the magnetic converging plate to which the present invention is applied, a soft magnetic material is preferably used. As the magnetic sensor element, a Hall element and a magnetoresistive element are preferable. As a substrate for forming the magnetic sensor, a Si, sapphire, GaAs substrate or the like is preferable. For the sensor unit, a Si Hall element using a CMOS silicon process or a compound semiconductor can be used. As a material of the compound semiconductor element constituting the sensor section, InSb, InAs, GaAs or the like having extremely high electron mobility is most preferably used. Further, GaSb or InP having an electron mobility higher than that of Si is preferably used. Further, ternary mixed crystals thereof, for example, InGaAs, InAsSb, InGaP, GaAsSb, InGaSb, and InAsP are also preferable. Further, quaternary mixed crystals such as InGaAsSb and InGaAsP are also preferably used. In the case where good temperature characteristics are required, GaN, InN, InGaN, and the like having a large band gap energy have a higher electron saturation speed than Si, and are preferably used.
[0071]
Further, in order to improve the temperature characteristics, it is preferable to dope the compound semiconductor with a donor impurity. As the donor impurity, Si, Te, S, Se, Ge, or the like is preferably used.
[0072]
In order to obtain a higher electron mobility, a heterostructure of the compound semiconductor, for example, AlGaAs / GaAs, AlGaAs / InGaAs, AlGaAsSb / InAs, AlGaAsSb / InGaAs, AlGaAsSb / InAsSb, AlGaAsSb / InGaAsSb, AlGaN / GaN, AlGaN It is also preferable to use / InGaN or the like. As these hetero structures, either a single hetero structure or a double hetero structure may be used. Further, a superlattice structure in which these heterostructures are repeatedly laminated may be formed.
[0073]
【The invention's effect】
As described above, according to the present invention, when detecting the magnetic field in the horizontal direction and the vertical direction, the deviation of the detection sensitivity caused by using the magnetic converging plate is eliminated, and the S to the magnetic field detection in the vertical direction is eliminated. / N ratio can be improved. In other words, according to the present invention, the direction dependency of the magnetic detection sensitivity due to the use of the magnetic converging plate is eliminated, and the calibration becomes unnecessary, and at the same time, the S / N ratio with respect to the magnetic field in the vertical direction is improved. A high-precision, small-sized and inexpensive three-dimensional magnetic sensor can be realized.
[Brief description of the drawings]
FIG. 1 is a plan view showing a three-dimensional magnetic sensor according to a first embodiment.
FIG. 2 is a cross-sectional configuration diagram of the three-dimensional magnetic sensor shown in FIG.
FIG. 3 is a diagram showing a simulation result using the magnetic sensor according to the present embodiment.
FIG. 4 is a circuit diagram for processing detection signals from the magnetic detection elements X1 to X4, Y1 to Y4, and Z1 to Z8 shown in FIG.
FIG. 5 is a view exemplifying magnetic converging plates having different shapes and magnetic detecting elements arranged at different positions.
FIG. 6 is a plan view showing a three-dimensional magnetic sensor according to a second embodiment.
7 is a circuit diagram for processing detection signals from the magnetic detection elements X1a, X1b, X2a, X2b, Y1a, Y1b, Y2a, Y2b, and Z1 to Z4 shown in FIG.
FIG. 8 is a diagram showing an analysis result by a magnetic simulation.
FIG. 9 is a plan view showing a three-dimensional magnetic sensor according to a third embodiment.
FIG. 10 is a sectional view showing one embodiment of a hybrid magnetic sensor to which the present invention is applied.
[Explanation of symbols]
X, Y, Z Magnetic sensing element (Hall element)
FC magnetic focusing plate

Claims (20)

A three-dimensional magnetic detecting device having a magnetic converging plate and a plurality of magnetic detecting elements formed on a substrate,
When arranging at least two pairs of magnetic detection elements in the vicinity of the end region of the magnetic converging plate and sequentially or simultaneously obtaining magnetic detection signals from the magnetic detection elements included in each magnetic detection element pair,
Total number of all magnetic sensing elements ≧ {(magnetic amplification factor of the magnetic converging plate with respect to a magnetic field in a plane direction parallel to the substrate) × (number of magnetic sensing elements per pair)} − 1
A three-dimensional magnetic detection device characterized by satisfying the following conditions. The three-dimensional magnetic detection device according to claim 1,
An integer closest to the value of (the number of magnetic sensing elements included in a pair of magnetic sensing elements) × (magnetic amplification factor of the magnetic converging plate with respect to a magnetic field in a plane direction parallel to the substrate), or an integer number or more. A three-dimensional magnetic detecting device, wherein a magnetic detecting element is selected, and a magnetic field intensity in a direction perpendicular to the substrate is detected using the selected magnetic detecting element. The three-dimensional magnetic detection device according to claim 1,
By detecting the X-direction component and the Y-direction component horizontal to the substrate by using the at least two pairs of magnetic detection elements, and providing a magnetic detection element provided in addition to the at least two pairs of magnetic detection elements. 3. A three-dimensional magnetic detector, wherein a Z-direction component perpendicular to the substrate is detected. The three-dimensional magnetic detection device according to claim 1,
3. The three-dimensional magnetic detection device according to claim 1, wherein the magnetic detection element is a Hall element formed on a silicon substrate. The three-dimensional magnetic detection device according to claim 1,
A three-dimensional magnetic detecting device, wherein all of the magnetic detecting elements or a part of the magnetic detecting elements are formed of a compound semiconductor. A three-dimensional magnetic detection device having a plurality of magnetic detection elements formed on a substrate,
At least two pairs of magnetic detecting elements for detecting components in two directions horizontal to the substrate are arranged close to an end region of the first magnetic converging plate, and
Separately from the at least two pairs of magnetic detecting elements, a magnetic detecting element for detecting a magnetic field strength in a direction perpendicular to the substrate is arranged, and a second magnetic converging plate is provided near and above the magnetic detecting elements. A three-dimensional magnetic detection device, characterized in that: The three-dimensional magnetic detection device according to claim 6,
An aspect ratio defined by (the length of the second magnetic converging plate) / (the thickness of the second magnetic converging plate) is 3 or less, wherein the three-dimensional magnetic detection device is characterized in that: The three-dimensional magnetic detection device according to claim 6 or 7,
3. The three-dimensional magnetic detection device according to claim 1, wherein the magnetic detection element is a Hall element formed on a silicon substrate. The three-dimensional magnetic detection device according to claim 6 or 7,
A three-dimensional magnetic detecting device, wherein all of the magnetic detecting elements or a part of the magnetic detecting elements are formed of a compound semiconductor. A three-dimensional magnetic detection device having a plurality of magnetic detection elements formed on a substrate,
At least two pairs of magnetic detecting elements for detecting components in two directions horizontal to the substrate are arranged close to an end region of the magnetic converging plate, and
A three-dimensional magnetic detecting device, comprising: a magnetic detecting element formed of a compound semiconductor for detecting a magnetic field strength in a direction perpendicular to the substrate, separately from the at least two pairs of magnetic detecting elements. . The three-dimensional magnetic detection device according to claim 10,
A three-dimensional magnetic detection device, wherein the magnetic detection element other than the magnetic detection element for detecting a magnetic field strength in a direction perpendicular to the substrate is a Hall element formed on a silicon substrate. The three-dimensional magnetic detection device according to claim 1, further comprising:
A three-dimensional magnetism detection device, comprising: a signal processing circuit that receives magnetism detection signals sequentially or simultaneously output from the magnetism detection element and performs predetermined signal processing or data processing. The three-dimensional magnetic detection device according to claim 12,
A three-dimensional magnetic detection device, wherein the signal processing circuit is formed on the same substrate on which the magnetic detection element is formed. 14. A semiconductor device, wherein the three-dimensional magnetic detection device according to claim 1 is formed on a semiconductor substrate. The semiconductor device having the three-dimensional magnetic detection device according to claim 5, wherein the compound semiconductor is formed on a separate substrate. 10. The semiconductor device according to claim 9, wherein the compound semiconductor is formed on a separate substrate. 11. The semiconductor device having the three-dimensional magnetic detection device according to claim 10, wherein the compound semiconductor is formed on a separate substrate. 13. The semiconductor device having the three-dimensional magnetic detection device according to claim 12, wherein the signal processing circuit is formed on a substrate separate from the magnetic detection element. 14. The three-dimensional magnetism detection device according to claim 1, wherein the magnetism is detected using the magnetism detection element. 19. The semiconductor device according to claim 14, wherein geomagnetism is detected by using the magnetic detection element.

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