JP5463562B2 - Semiconductor device and manufacturing method thereof - Google Patents

Description

  The present invention relates to a semiconductor device and a manufacturing method thereof, and more particularly, to a semiconductor device including a soft magnetic thin film having a low coercive force and a low residual magnetic flux density, and magnetically converging with the soft magnetic thin film, and a manufacturing method thereof. The present invention relates to a magnetic sensor including a Hall element.

  It is known that a conventional magnetic sensor including a Hall element is provided with a soft magnetic thin film immediately above the Hall element for magnetic convergence (see, for example, Patent Document 1). In such a magnetic sensor, a soft magnetic thin film is arranged on the Hall element, so that the Hall element can detect the magnetic flux leaking from the end of the magnetic focusing plate with high sensitivity due to the magnetic convergence effect. The thin film has a feature that a NiFe alloy thin film is formed by electrolytic plating.

  FIG. 1 is a diagram showing a hysteresis curve of a soft magnetic thin film. Since a soft magnetic thin film that performs magnetic convergence is a magnetic material, the saturation flux density output from the magnetic material with respect to an external magnetic field is as shown in FIG. A simple hysteresis curve is shown. Further, the amount of hysteresis can be defined by the magnitude of the residual magnetic flux density at the intersection of the coercive force that is the intersection of the X axis and the Y axis in the hysteresis curve shown in FIG. However, since the amount of hysteresis varies depending on the direction of application of the magnetic field and the magnitude of the external magnetic field even with the same amount of external magnetic field, it is necessary to reduce the amount of hysteresis in order to realize more advanced magnetic sensing.

JP 2003-142752 A

  However, in order to reduce the amount of hysteresis, it is necessary to reduce the coercive force and the residual magnetic flux density. In the conventional technique, the coercive force is 30 to 100 A / m, the residual magnetic flux density is 0.6 to 1.1 T, and the magnetic sensor has a hysteresis of about 0.1 to 1.0 mT. The magnetic field of use of the magnetic sensor is used in a wide range of several mT to several hundreds of mT. In particular, in the magnetic field of use of several mT, an error of about 10% occurs even with a hysteresis of 0.1 mT. There has been a problem that it cannot be applied to applications that require more accurate measurement. Therefore, it is necessary to further reduce the coercive force and the residual magnetic flux density in order to realize more accurate magnetic sensing.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a semiconductor device including a soft magnetic film having a low coercive force and a low residual magnetic flux density, and magnetically converging with the soft magnetic thin film, and It is in providing the manufacturing method.

The present invention has been made to achieve such an object, and the invention according to claim 1 is a semiconductor device comprising a semiconductor substrate, a Hall element provided on the semiconductor substrate, and the hole. It provided on an underlying conductive layer made of Cu-based material on the element, and a soft magnetic thin film formed by electroless plating, with a, a semiconductor device for the magnetic flux concentrator in the soft magnetic thin film, the soft magnetic thin film When the coercive force is 0.1 to 30 A / m, the residual magnetic flux density is 0.05 to 0.6 T, and the total of iron, nickel, and boron contained in the soft magnetic thin film is 100% by weight Further, the iron content is 15 to 30% by weight, the boron content is 0.2 to 0.6% by weight, the balance is nickel, the thickness is 4 to 30 μm, and the crystallites of the soft magnetic thin film The size is 10 nm or less and the crystal Position, characterized in that the oriented direction more than 70% (111).

  According to the present invention, a Hall element provided on a semiconductor substrate and a soft magnetic thin film provided on the Hall element are provided. Since the soft magnetic thin film contains at least boron, low coercive force and A semiconductor device including a soft magnetic film having a low residual magnetic flux density and magnetically converging with the soft magnetic thin film and a method for manufacturing the same can be provided.

  Further, when the total amount of iron, nickel, and boron contained in the soft magnetic thin film is 100% by weight, the iron content is 15 to 30% by weight, the boron content is 0.2 to 0.6% by weight, and the balance Is a nickel, and the soft magnetic thin film has a thickness of 4 to 30 μm. Since the soft magnetic thin film is magnetically collected, magnetic sensing can be performed accurately even in a magnetic field environment of several mT, and the amount of hysteresis is reduced. By reducing it, the absolute value of the unbalanced voltage and its variation can be reduced.

It is a figure which shows the hysteresis curve of a soft-magnetic thin film. It is a block diagram for describing one embodiment of a semiconductor device according to the present invention. FIG. 4 is a process diagram for explaining a method of manufacturing the semiconductor device shown in FIG. 2 and a process diagram for forming a semiconductor circuit. FIG. 5 is a process diagram for explaining a method of manufacturing the semiconductor device shown in FIG. 2 and a process diagram for forming a base conductive layer. FIG. 4 is a process diagram for explaining a method of manufacturing the semiconductor device shown in FIG. 2 and a process diagram for forming a resist pattern on a base conductive layer. FIG. 4 is a process diagram for explaining a method of manufacturing the semiconductor device shown in FIG. 2 and a process diagram for forming a soft magnetic thin film. FIG. 4 is a process diagram for explaining the method of manufacturing the semiconductor device shown in FIG. 2 and a process diagram for removing a resist. FIG. 4 is a process diagram for explaining a method of manufacturing the semiconductor device shown in FIG. 2 and a process diagram for removing a base conductive layer. It is a figure which shows the relationship between the boron content and the coercive force in the soft magnetic thin film in Example 1 and Comparative Example 1. It is a figure which shows the relationship between the boron content and residual magnetic flux density in Example 1 and Comparative Example 1. It is a figure which shows the relationship between the boron content in the soft-magnetic thin film in Example 1 and Comparative Example 1, and a (111) orientation degree (crystal orientation). It is a figure which shows the relationship between the boron content in the soft-magnetic thin film in Example 1 and the comparative example 1, and a crystallite size. It is a figure which shows the relationship between the amount of TMAB addition to the plating solution in Example 1 and Comparative Example 1 and the boron content in the soft magnetic thin film. It is a figure which shows the relationship between the film thickness of a soft-magnetic thin film and coercive force in Example 2 and Comparative Example 2. It is a figure which shows the relationship between the film thickness of the soft-magnetic thin film in Example 2 and Comparative Example 2, and a residual magnetic flux density.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 2 is a block diagram for explaining an embodiment of a semiconductor device according to the present invention, in which reference numeral 1 denotes a semiconductor substrate, 2 denotes a Hall element, 3 denotes an external connection terminal pad, 4 denotes an organic insulating film, 5 Indicates a base conductive layer (metal conductive film), and 6 indicates a soft magnetic thin film.

  The semiconductor device of the present invention is a semiconductor device having a small amount of hysteresis by providing a soft magnetic thin film containing a predetermined amount of boron on a Hall element compared to a semiconductor device that has been magnetically converged by a conventional magnetic material. It is obtained. The semiconductor device of the present invention includes a magnetic sensor provided with a Hall element.

  The semiconductor device of the present invention includes a Hall element 2 provided on a semiconductor substrate 1 and a soft magnetic thin film 6 provided on the Hall element 1, and the soft magnetic thin film 6 contains at least boron. . In addition, an organic insulating film 4 provided on the semiconductor substrate 1 and on the Hall element 2 and a metal conductive layer 5 provided between the organic insulating film 4 and the soft magnetic thin film 6 are provided. A thin film 6 is disposed on the metal conductive layer 5 so as to cover at least one magnetic sensing portion of the Hall element 2.

  That is, the semiconductor device of the present invention is characterized in that the semiconductor substrate 1 is provided with the Hall element 2, the organic insulating film 4 is provided on the semiconductor substrate 1, and the underlying conductive layer 5 and the soft magnetic thin film 6 are provided immediately above the Hall element 1. Is provided.

  The soft magnetic thin film 6 has an iron content of 15 to 30% by weight and a boron content of 0.2 to 0.6% by weight when the total of iron, nickel and boron contained in the film is 100% by weight. The balance is nickel, and the coercive force and residual magnetic flux density can be reduced by controlling the thickness to 4 to 30 μm. Incidentally, the crystallite size in the soft magnetic thin film at that time is 5 to 10 nm, and the crystal orientation degree of NiFe (111) is 70 to 100%. The coercive force of the soft magnetic thin film is 0.1 to 30 A / m, and the residual magnetic flux density is 0.05 to 0.6 T.

  3 to 8 are process diagrams for explaining a method of manufacturing the semiconductor device shown in FIG. In the method of manufacturing a semiconductor device according to the present invention, an organic insulating film 4 is formed on a semiconductor substrate provided with one or more Hall elements and a semiconductor circuit, and a metal conductive layer 5 is formed on the organic insulating film 4. The soft magnetic thin film 6 containing at least boron is formed on the metal conductive layer 5 and at a position covering the magnetically sensitive portion of one or more Hall elements. The soft magnetic thin film 6 is formed by electrolytic plating using a plating solution containing a boron reducing agent.

Below, the manufacturing method of the semiconductor device which concerns on this invention is demonstrated along process order.
FIG. 3 is a process diagram for explaining a method of manufacturing the semiconductor device shown in FIG. 2, and is a process diagram for forming a semiconductor circuit. First, as shown in FIG. 3, at least one Hall element 2 for magnetic sensing is disposed on the semiconductor substrate 1, and the external connection terminal pad 3 is opened for electrical connection with the external electrode. An organic insulating film 4 is formed. The semiconductor substrate 1 may be either a silicon wafer or a GaAs substrate, and the Hall element 2 is preferably a semiconductor such as Si or a compound semiconductor such as InSb, InAs, or GaAs, and the stacked structure or impurities thereof may be Sn, Zn, Si, or the like. You may use what doped. Further, as the material of the external connection terminal pad 3, an AL-based material or an Au-based material is generally used. The organic insulating film 4 is preferably made of an organic material such as polyimide, polybenzoxazole, or benzocyclobutene.

  FIG. 4 is a process diagram for explaining the method of manufacturing the semiconductor device shown in FIG. 2, and is a process diagram for forming a base conductive layer. Next, as shown in FIG. 4, the base conductive layer 5 is disposed on the organic insulating film 4 and the external connection terminal pads 3. A laminated film is used as the base energizing layer 5, a Ti-based material such as Ti or TiW as the first layer, a Cu-based material, an AL material, or a NiFe-based material as the second layer by vacuum evaporation, sputtering, It is formed by electrolytic / electroless plating. The Ti-based material desirably has a thickness of at least 0.1 μm or more as a diffusion barrier layer of the Al-based material of the external connection terminal pad 3 and the Cu-based material of the ground conductive layer 5.

  Further, the second layer, Cu-based material, AL material, and NiFe-based material are preferably thicker in order to lower the electrical resistance, and preferably 0.1 to 10 μm. Cu is oriented in the crystal orientation of (111). In order to reduce the mismatch of the crystal orientation of the soft magnetic thin film 6, it is better to use Cu having the crystal orientation of (111) as a layer for depositing the soft magnetic thin film 6.

  FIG. 5 is a process diagram for explaining a method of manufacturing the semiconductor device shown in FIG. 2, and is a process diagram for forming a resist pattern on the underlying conductive layer. Next, as shown in FIG. 5, a resist 7 is formed on the underlying conductive layer 5 in order to form a pattern of the soft magnetic thin film 6, and exposure and development are performed to form a resist gap 7a. As the resist material, either a positive resist or a negative resist may be used, but in general, a naphthoquinone diazo type positive resist capable of satisfying both acid resistance and releasability during plating is desirable. The resist 7 can be formed to a maximum film thickness of 40 μm by using a positive resist of ftquinone diazo type. Further, since the resist 7 needs to be thicker than the soft magnetic thin film 6, it is preferably 5 to 40 μm.

  FIG. 6 is a process diagram for explaining a method of manufacturing the semiconductor device shown in FIG. 2, and is a process diagram for forming a soft magnetic thin film. Next, as shown in FIG. 6, a soft magnetic thin film 6 made of boron, nickel and iron is formed in the resist opening 7a by electrolytic plating. The soft magnetic thin film 6 is preferably thicker in order to achieve the magnetic convergence effect. However, if the film is thicker than the resist 7, the soft magnetic thin film 6 does not grow vertically but grows in a mushroom shape. Therefore, the film thickness of the soft magnetic thin film 6 is desirably smaller than the film thickness of the resist 7, and is particularly preferably in the range of 4 to 30 μm.

  In order to perform electroplating, the cathode on which the conductive layer 5 is formed is used as a cathode, and a soluble or insoluble metal plate such as nickel, iron, or platinum is used as an anode. A soft magnetic thin film can be formed on the portion to be plated. As the plating solution, nickel sulfate, nickel chloride, iron sulfate, boric acid, saccharin, sodium chloride and boron-based reducing agents such as tetramethylamine borane (TMAB) and dimethylamine borane (DMAB) were used. Boron was co-deposited in the soft magnetic thin film by adding TMAB or DMAB to the plating solution.

  In addition, when electrolytic plating is performed using this plating solution, the deposition potential of the plating film changes depending on the temperature of the plating solution, so the temperature of the plating solution must be heated and cooled using a thermocouple, heater, or chiller. is there. The temperature of the plating solution varies greatly depending on plating conditions such as current density and pH, but is preferably 20 to 60 ° C. Also, it is necessary to optimize the cathode current density and pH during plating. The cathode current density is preferably 1 to 70 mA / cm 2. When the pH is lowered to 2.0 or less, the amount of hydrogen generated increases, and the plating thickness becomes thin even during the same plating time. Therefore, the pH is preferably 2.0 or more.

  FIG. 7 is a process diagram for explaining the method of manufacturing the semiconductor device shown in FIG. 2, and is a process diagram for removing the resist. Next, as shown in FIG. 7, the resist 7 is removed. As a result, the soft magnetic thin film 6 remains on the underlayer conductive layer 5.

  FIG. 8 is a process diagram for explaining the method of manufacturing the semiconductor device shown in FIG. 2, and is a process diagram for removing the underlying conductive layer. Finally, as shown in FIG. 8, the base conductive layer 5 that is no longer needed is removed by a dry etching method or a wet etching method using the soft magnetic thin film 6 as a mask. At that time, it is important to prevent the magnetic material from being etched at the same time.

  As an evaluation method for soft magnetic thin films formed by electroplating, boron content is calculated using inductively coupled plasma emission spectrometry (ICP), and NiFe orientation and crystallite size are calculated using X-ray diffraction. did. Further, the magnetic characteristics were measured using a vibrating sample magnetometer (VSM).

  The amount of boron in the soft magnetic thin film 6 was measured using inductively coupled plasma emission spectrometry (ICP). A soft magnetic thin film is put into hydrochloric acid (1 + 1) and nitric acid, heated on a heater, the soft magnetic film and the base energizing layer are dissolved, and the emission intensity of nickel, iron and boron is measured by ICP, and the concentration is known. The content of each element was calculated from a calibration curve in which standard samples of nickel, iron and boron were dissolved. The content in the soft magnetic thin film was expressed in terms of wt% of the content of each element when the total of nickel, iron and boron was 100 wt%.

  The crystal orientation of the soft magnetic thin film was measured by an X-ray diffraction method at 2θ / ω in the out of plane direction using Cu Kα ray as an excitation line, and (111) and (200 ) To calculate the integrated value of the peak intensities of (111) and (111) by evaluating how much of the peak integrated value of (111) is relative to the sum of the peak integrated values of (111) and (200). The degree (%) was evaluated. The crystallite size was calculated using the Scherrer equation from the half-value width of the (111) peak of the alloy of Ni and Fe obtained from X-ray diffraction.

  Magnetic characteristic measurement is performed by setting a semiconductor device chip on which a soft magnetic thin film is formed on a sample table and drawing a magnetization curve generated when the sample is vibrated while generating a magnetic field by an electromagnet. Density was calculated.

  Hereinafter, each example will be described in detail based on the embodiment of the present invention. Note that the present invention is not limited to these examples.

[Example 1 and Comparative Example 1]
First, Example 1 and Comparative Example 1 of the soft magnetic thin film according to the semiconductor device of the present invention will be described.
Using a silicon substrate as the semiconductor substrate 1, an IC in which a signal processing circuit and a Hall element are combined is formed. The external connection terminal pad 3 of the IC is formed using Al, and the Al pad is opened to form polyimide with a thickness of 5 μm.

  On top of that, the base energizing layer 5 was formed by sputtering using Ti of 1500 mm and Cu of 6000 mm, and using a 20 μm positive rest, a 300 μm circular opening was opened by exposure and development processing for each chip unit of the IC.

  The semiconductor substrate 1 in which the resist was opened was set as a cathode in a plating holder, and a nickel plate having a purity of 4N was used as an anode. The substrate was immersed in electrolytic plating and energized to perform electroplating. As a plating solution for electrolysis, added to a plating solution containing 5 g / L of iron sulfate heptahydrate, 35 g / L of nickel sulfate hexahydrate, and 85 g / L of nickel chloride hexahydrate As a chemical agent, boric acid and sodium chloride were mixed at 25 g / L and sodium saccharate at 1.5 g / L respectively. Finally, a chemical solution in which the pH of the plating solution was adjusted with p3.6 using 1N hydrochloric acid was used for plating. The cathode current density at the time was fixed at 6 mA / cm 2, and the liquid temperature was fixed at 30 ° C. As Example 1, TMAB was 0.3, 2.5, 4.0, 8.0, 12.0, 15.0 g. Electrolytic plating was performed by adding / L.

  Further, as Comparative Example 1, without adding TMAB, the plating time was adjusted so that the thickness of the soft magnetic thin film was 13 μm as in the example, and electrolytic plating was performed.

  Next, the resist was removed with an organic solvent made of NMP, and Ti and Cu were removed by a wet etching method to produce a semiconductor device of the present invention.

  The soft magnetic thin film of the prepared semiconductor device was dissolved in hydrochloric acid (1 + 1) and nitric acid, and ICP measurement was performed to identify the boron content in the soft magnetic thin film. In addition, X-ray diffraction is performed with the soft magnetic thin film attached to the semiconductor device, the magnetic orientation is evaluated by crystal orientation and crystal size, and VSM, and the amount of TMAB added is changed to change the amount of the soft magnetic thin film. The effect of magnetic properties and crystal structure by changing boron content was experimentally confirmed.

  FIG. 9 is a diagram showing the relationship between the boron content and the coercive force in the soft magnetic thin film in Example 1 and Comparative Example 1, and FIG. 10 shows the boron content and the residual magnetic flux density in Example 1 and Comparative Example 1. It is a figure which shows a relationship.

  It was found that the coercive force and the residual magnetic flux density decrease as the amount of boron in the soft magnetic thin film 6 increases. In Comparative Example 1 in which boron is not contained in the soft magnetic thin film 6, the coercive force is 37 A / m, the residual magnetic flux density is 0.67 T, and the soft magnetic thin film 6 contains 0.2 wt% of boron. The magnetic force decreases to 22 A / m, the residual magnetic flux density decreases to 0.35 T, and the coercive force and residual magnetic flux density decrease as the boron content increases until the boron content reaches 0.4 wt%. However, when the boron content is 0.62 wt%, the coercive force is slightly increased to 15 A / m and the residual magnetic flux density is slightly increased to 0.20 T, but it has been confirmed that hysteresis can be reduced as compared with the prior art. Thus, in order to reduce the hysteresis, it was experimentally confirmed that the boron content in the soft magnetic thin film 6 is preferably 0.2 to 0.6 wt%.

  FIG. 11 is a diagram showing the relationship between the boron content in the soft magnetic thin film and ((111) degree of orientation (crystal orientation) by X-ray diffraction in Example 1 and Comparative Example 1, and FIG. It is a figure which shows the relationship between the boron content and the crystallite size in the soft-magnetic thin film in the comparative example 1.

  It can be seen that the greater the amount of boron incorporated into the soft magnetic thin film 6, the more the crystal orientation is oriented in the (111) direction and the crystallite size is smaller. Therefore, if the amount of boron in the soft magnetic thin film 6 is 0.2 wt% or more, regardless of the amount of boron incorporation, 70% or more is oriented in the direction of (111) and the crystallite size is 10 nm or less. It was confirmed experimentally that the magnetic thin film 6 can be formed.

  FIG. 13 is a diagram showing the relationship between the amount of TMAB added to the plating solution and the boron content in the soft magnetic thin film in Example 1 and Comparative Example 1. The boron content in the soft magnetic thin film 6 depends on the amount of TMAB that is a boron-based reducing agent added to the plating solution. By adding TMAB to the plating solution in an amount of 2 g / L or more, 0.2 wt% of boron is contained in the soft magnetic thin film 6, and by increasing the amount of TMAB, the amount of boron in the film increases. In this experiment, it was confirmed that 0.62 wt% boron can be contained in the soft magnetic thin film 6 when TMAB is added as a maximum addition amount of 15 g / L.

  Thus, a soft magnetic film having a small coercive force and residual magnetic flux density could be obtained by adding TMAB to the plating solution and containing boron in the film.

[Example 2 and Comparative Example 2]
Next, Example 2 and Comparative Example 2 according to the semiconductor device of the present invention will be described.
When used as a magnetic sensing application, the soft magnetic thin film 6 is preferably thick in order to prevent magnetic saturation. Only in the electroplating process, the amount of TMAB added was fixed at 12.0 g / L, the current density was fixed at 6 mA / cm2, the liquid temperature was fixed at 30 ° C., and the film thickness was changed by changing the plating time. Example 2 was performed. Similarly, an experiment was conducted as Comparative Example 2 in which the film thickness was changed by changing the plating time without adding TMAB.

  14 is a diagram showing the relationship between the thickness of the soft magnetic thin film and the coercive force in Example 2 and Comparative Example 2, and FIG. 15 is the thickness and residual magnetic flux density of the soft magnetic thin film in Example 2 and Comparative Example 2. It is a figure which shows the relationship.

  When the film thickness is changed, the coercive force and the saturation magnetic flux density change greatly. When TMAB is not added, the coercive force is 120 A / m for a 1 μm thin film, and the coercive force decreases as the film thickness increases. While it is saturated at about 40 A / m at a thickness of 8 μm or more, by adding 12.0 g / L of TMAB, the coercive force can be reduced to 40 A / m even at 1 μm, and at about 20 A / m or less at a thickness of 4 μm or more. It turns out that it becomes constant. Further, the saturation magnetic flux density is 0.9 T for a thin film having a thickness of 1 μm, and is slightly reduced as the film thickness is increased, but only decreases to about 0.7 T. On the other hand, the saturation magnetic flux density is 0.6T even at 1μm by adding 12.0g / L of TMAB, and it is reduced to about 0.1T by increasing TMAB, and the residual magnetic flux density changes to the film thickness of 32μm. I confirmed that I did not.

  Thereby, in order to realize a coercive force of 30 A / m or less and a residual magnetic flux density of 0.6 T or less, it was experimentally confirmed that the thickness of the soft magnetic thin film 6 is desirably 4 to 30 μm.

[Example 3]
Next, a third embodiment according to the semiconductor device of the present invention will be described.
When the soft magnetic thin film 6 is produced using electrolytic plating, the current density at the time of plating is an important factor in determining the productivity. By increasing the current density, the plating time can be shortened, which directly improves productivity. Therefore, as Example 3, plating was performed with a current density of 30 mA / cm 2 which is five times that of Examples 1 and 2, a TMAB addition amount of 12.0 g / L, and a film thickness of 13 μm. The boron content by ICP was 0.5 wt%, the coercive force was 15 A / m, and the residual magnetic flux density was 0.12 T. Even when the current density was increased, the soft magnetic thin film 6 with low hysteresis could be produced. At that time, the NiFe (111) orientation degree of the soft magnetic thin film 6 was 95%, and the crystallite size was 8.5 nm.

[Example 4 and Comparative Example 3]
Next, Example 4 and Comparative Example 3 according to the semiconductor device of the present invention will be described.
GaAs was used as the semiconductor substrate 1, and a compound semiconductor made of InAs was used as the Hall element 2. The external electrode was formed by depositing a laminated structure of Ti and Au. A polyimide is formed in a thickness of 5 μm immediately above the Hall element 2, and a resist pattern is formed on the base energizing layer 5 formed by sputtering with Ti of 1500 mm and Cu of 6000 mm. A soft magnetic thin film 6 having a thickness of 13 μm was formed using a plating solution containing 12 g / L of TMAB described in Example 3.

  Moreover, the soft magnetic thin film 6 was formed in thickness of 13 micrometers using the plating solution which does not add TMAB as the comparative example 2. FIG. The hysteresis width of the Hall electromotive force when 3 V was applied was evaluated while changing the magnetic field from +40 mT → −40 mT → + 40 mT on the element formed by resist stripping and etching.

  The hysteresis widths of Example 4 and Comparative Example 3 were compared. The hysteresis width is the difference between the amount of magnetic field where the Hall output becomes zero when the magnetic field is changed from +40 mT to −40 mT, and the magnetic field amount when the Hall output becomes zero when the magnetic field is changed from −40 mT to +40 mT. When defined, the hysteresis width of 0.01 mT in Example 4 is 0.1 mT in Comparative Example 3, and that the hysteresis width is reduced to about 1/10 by adding TMAB as an experimental Hall element. It could be confirmed.

  By doing so, it is possible to perform magnetic sensing with high accuracy even in a magnetic field environment of several mT. Moreover, it can be expected that the absolute value of the unbalanced voltage and its variation can be reduced by reducing the amount of hysteresis.

DESCRIPTION OF SYMBOLS 1 Semiconductor substrate 2 Hall element 3 External connection terminal pad 4 Organic insulating film 5 Ground conductive layer (metal conductive film)
6 Soft magnetic thin film 7 Resist 7a Resist gap

Claims (1)

A semiconductor substrate;
Hall elements provided on the semiconductor substrate;
A soft magnetic thin film provided on an underlying conductive layer made of a Cu-based material on the Hall element and formed by electrolytic plating ;
A semiconductor device that converges magnetically with the soft magnetic thin film,
The coercive force of the soft magnetic thin film is 0.1 to 30 A / m, the residual magnetic flux density is 0.05 to 0.6 T, and the total of iron, nickel, and boron contained in the soft magnetic thin film is 100 wt. %, The iron content is 15-30 wt%, the boron content is 0.2-0.6 wt%, the balance is nickel, the thickness is 4-30 μm, and the soft magnetic thin film The size of the crystallite is 10 nm or less, and the crystal orientation is 70% or more oriented in the direction of (111).

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