Vertical hall element

Abstract

To provide a vertical hall element in which the spread of the current path of the sensing current flowing through the semiconductor region is suppressed.SOLUTION: A vertical hall element 1 comprises a conductive first semiconductor layer 20 defined on both sides by mutually opposing first and second surfaces 201 and 202, and a first magnetic sensitive layer 301 of conductive semiconductor in the shape of a mesa, located above the first surface 201 of the first semiconductor layer 20, with the bottom surface facing the first surface 201. In at least part of the first magnetic sensitive layer 301 from the bottom surface to the top surface opposite the bottom surface, the cross-section parallel to the bottom surface is divided into a first region 321 and a second region 322 that is less conductive than the first region 321.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a vertical Hall element.

Background Art

[0002] A vertical Hall element that detects a magnetic field parallel to a substrate is used for a Hall element that detects a magnetic field using the Hall effect. In the vertical Hall element, a detection current for detecting a magnetic field flows in a direction perpendicular to the substrate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

[0004] [Summary] When a vertical Hall element has a spread in the current path of the detection current flowing through the semiconductor region, the sensitivity decreases. An object of the present disclosure is to provide a vertical Hall element in which the spread of the current path of the detection current flowing through the semiconductor region is suppressed.

[0005] One aspect of the present disclosure is a vertical Hall element including a conductive first semiconductor layer having both a first surface and a second surface that face each other, and a first magnetic-sensitive layer of a mesa-shaped conductive semiconductor disposed above the first surface of the first semiconductor layer and having a bottom surface facing the first surface. In at least a part from the bottom surface to the upper surface facing the bottom surface of the first magnetic-sensitive layer, a cross section parallel to the bottom surface is divided into a first region and a second region having lower conductivity than the first region.

Brief Description of the Drawings

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[0007] [Detailed Description] Next, embodiments will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thicknesses of the respective parts, etc. are different from the actual ones. Also, it goes without saying that there are portions where the dimensional relationships or ratios are different between the drawings.

[0008] Moreover, the embodiments shown below exemplify an apparatus or method for embodying a technical idea, and do not specify the shape, structure, arrangement, etc. of the constituent parts as the following. Various changes can be made to these embodiments within the scope of the claims.

[0009] As shown in FIG. 1, the vertical hall element 1 according to the first embodiment includes a first semiconductor layer 20 having both surfaces defined by a first surface 201 and a second surface 202 facing each other, and a first magnetosensitive layer 301 and second magnetosensitive layers 302A and 302B disposed above the first surface 201. Hereinafter, when not limiting each of the second magnetosensitive layer 302A and the second magnetosensitive layer 302B, they are denoted as the "second magnetosensitive layer 302". The second magnetosensitive layer 302 is disposed above the first surface 201 at a position separated from the first magnetosensitive layer 301. Also, when not limiting each of the first magnetosensitive layer 301 and the second magnetosensitive layer 302, they are denoted as the "magnetosensitive layer 30". The magnetosensitive layer 30 and the first semiconductor layer 20 are electrically connected.

[0010] The magnetosensitive layer 30 has a mesa shape in which the bottom surface faces the first surface 201 and the side surface extends in a direction intersecting the first surface 201. As shown in FIG. 1, the side surface of the magnetosensitive layer 30 is exposed. The direction from the bottom surface to the upper surface of the magnetosensitive layer 30 shown in FIG. 1 is perpendicular to the first surface 201. However, the direction from the bottom surface to the upper surface of the magnetosensitive layer 30 may be oblique rather than perpendicular to the first surface 201.

[0011] The materials of the first semiconductor layer 20 and the magnetosensitive layer 30 are conductive semiconductors. For example, the materials of the first semiconductor layer 20 and the magnetosensitive layer 30 may be Si (silicon) semiconductors, or compound semiconductors such as gallium arsenide (GaAs), indium phosphide (InP), indium antimonide (InSb), aluminum gallium arsenide (AlGaAs), etc. Hereinafter, the case where the materials of the first semiconductor layer 20 and the magnetosensitive layer 30 contain GaAs will be exemplarily described.

[0012] As shown in FIG. 1, the thickness direction of the first semiconductor layer 20 (the direction from the second surface 202 to the first surface 201) is defined as the Z direction. In FIG. 1, the Z direction is the vertical direction of the paper surface. Also, a plane perpendicular to the Z direction is defined as the XY plane defined by the X direction and the Y direction. In FIG. 1, the X direction is the left-right direction of the paper surface, and the Y direction is the depth direction of the paper surface. In the present disclosure, in the Z direction, the direction in which the magnetosensitive layer 30 is located as viewed from the first semiconductor layer 20 is defined as the upward direction, and the direction in which the first semiconductor layer 20 is located as viewed from the magnetosensitive layer 30 is defined as the downward direction. For each layer of the vertical hole element 1, the surface facing upward is also referred to as the upper surface, and the surface facing downward is also referred to as the lower surface or the bottom surface. For example, the first surface 201 is the upper surface of the first semiconductor layer 20, and the second surface 202 is the lower surface of the first semiconductor layer 20.

[0013] The vertical hole element 1 shown in FIG. 1 has a configuration in which two second magnetosensitive layers 302 are arranged with the first magnetosensitive layer 301 interposed therebetween. In other words, along the X direction, the second magnetosensitive layer 302A, the first magnetosensitive layer 301, and the second magnetosensitive layer 302B are arranged in this order.

[0014] The first semiconductor layer 20 may be, for example, a GaAs semiconductor layer doped with an n-type impurity. The impurity concentration of the first semiconductor layer 20 is, for example, 1E17 cm -3 ~1E19 cm -3 . The magnetosensitive layer 30 may be, for example, a GaAs semiconductor layer doped with an n-type impurity. The impurity concentration of the magnetosensitive layer 30 is, for example, 1E16 cm -3 ~1E17 cm -3 . The n-type impurity may be, for example, Si, selenium (Se), or tellurium (Te).

[0015] As shown in Fig. 1, the vertical Hall element 1 includes a first main electrode 401 disposed on the upper surface of the first magnetosensitive layer 301, a second main electrode 402A disposed on the upper surface of the second magnetosensitive layer 302A, and a second main electrode 402B disposed on the upper surface of the second magnetosensitive layer 302B. Hereinafter, when not limiting each of the second main electrode 402A and the second main electrode 402B, it is denoted as "second main electrode 402". Also, when not limiting each of the first main electrode 401 and the second main electrode 402, it is denoted as "main electrode 40". The material of the main electrode 40 may be, for example, gold (Au), gold germanium (AuGe) / nickel (Ni), titanium (Ti) / gold (Au), titanium (Ti) / platinum (Pt) / gold (Au), etc.

[0016] The first main electrode 401 is the first end of the current path of the detection current Is flowing from the first magnetosensitive layer 301 through the first semiconductor layer 20 to the second magnetosensitive layer 302. The second main electrode 402 is the second end of the current path of the detection current Is. For example, a power source for flowing the detection current Is from the first main electrode 401 to the second main electrode 402 is prepared outside the vertical Hall element 1.

[0017] The vertical Hall element 1 shown in Fig. 1 further includes a substrate 10 connected to the second surface 202 of the first semiconductor layer 20. For the substrate 10, for example, a semi-insulating substrate or an insulating substrate may be used. The substrate 10 may be, for example, a GaAs substrate, an InP substrate, an InSb substrate, a Si substrate, etc. By using a semi-insulating substrate or an insulating substrate for the substrate 10, electrical insulation of the substrate 10 with respect to the first semiconductor layer 20 is ensured, and the detection current Is does not flow through the substrate 10.

[0018] As shown in FIG. 1, in at least a part from the bottom surface to the upper surface facing the bottom surface of the first magnetosensitive layer 301, a cross-section parallel to the bottom surface is divided into a first region 321 and a second region 322. The second region 322 is a region with lower conductivity than the first region 321. The detection current Is flows through the first region 321 in the first magnetosensitive layer 301 and does not flow through the second region 322. In other words, in the portion divided into the first region 321 and the second region 322, the region where the detection current Is flows is narrowed. Hereinafter, the portion where the cross-section parallel to the bottom surface is divided into the first region 321 and the second region 322 is also referred to as a "current constriction portion". The first region 321 is disposed directly below along the Z direction of the first main electrode 401, and the second region 322 is disposed around the first region 321 in the current constriction portion. Therefore, the detection current Is can flow in the first magnetosensitive layer 301 in a direction perpendicular to the bottom surface.

[0019] In the vertical hall element 1 shown in FIG. 1, the second region 322 of the current constriction portion may be formed of an insulating material. For example, when viewed from the Z direction, the first region 321, which is a conductive semiconductor, is disposed sandwiched between the second regions 322 of the insulating layer. The current constriction portion of the vertical hall element 1 shown in FIG. 1 is formed in a region in contact with the bottom surface of the first magnetosensitive layer 301.

[0020] The current constriction portion shown in FIG. 1 may be formed, for example, by oxidizing a part of the conductive semiconductor layer using a selective oxidation technique. For example, on the first surface 201 of the first semiconductor layer 20, an aluminum arsenide (AlAs) film and a semiconductor film (hereinafter also referred to as a "magnetic sensing layer film") for forming the first magnetic sensing layer 301 are laminated. Then, in the step of etching away a part of the magnetic sensing layer film to form the first magnetic sensing layer 301 in a mesa shape, the AlAs film in the region overlapping the first magnetic sensing layer 301 is left as the bottom of the first magnetic sensing layer 301. Thereafter, the AlAs film is heat-treated in a water vapor atmosphere by a selective oxidation technique to selectively oxidize the AlAs film in the lateral direction. The portion where the AlAs film is oxidized to form an AlOx film in this step is the second region 322. And the unoxidized portion of the AlAs film is the first region 321. Although an example of oxidizing the AlAs film to form the second region 322 has been described above, it goes without saying that a film other than the AlAs film (for example, an AlGaAs film, etc.) may be used.

[0021] FIG. 2 shows a plan view of the first magnetic sensing layer 301 as viewed from the Z direction. The length (hereinafter also referred to as "width") of the first main electrode 401 and the first region 321 along the X direction may be about the same. Alternatively, the width of the first region 321 may be wider than the width of the first main electrode 401, or the width of the first region 321 may be narrower than the width of the first main electrode 401.

[0022] In the vertical Hall element 1, the detection current Is flowing between the first main electrode 401 and the second main electrode 402 flows along the Z direction, which is the normal direction of the first surface 201 of the first semiconductor layer 20 in the first magnetic sensing layer 301. In other words, the detection current Is flows in a direction perpendicular to the main surface of the substrate 10. By the detection current Is flowing in a direction perpendicular to the main surface of the substrate 10, as will be described later, the vertical Hall element 1 can detect a magnetic field in a direction parallel to the main surface of the substrate 10.

[0023] As shown in FIG. 3, the vertical Hall element 1 further includes a pair of first Hall electrodes 501 and second Hall electrodes 502 that are respectively disposed on the upper surface of the first magnetosensitive layer 301 with the first main electrode 401 interposed therebetween. Hereinafter, when not limiting each of the first Hall electrode 501 and the second Hall electrode 502, they are referred to as "Hall electrode 50". The material of the Hall electrode 50 is the same as that of the main electrode 40 described above.

[0024] A Lorentz force is generated in the vertical Hall element 1 by a magnetic field parallel to the first surface 201 of the first semiconductor layer 20 and a detection current Is flowing through the first magnetosensitive layer 301 in a direction perpendicular to the first surface 201. As will be described below, the vertical Hall element 1 is configured such that the Hall output voltage caused by the Lorentz force can be detected by the Hall electrode 50.

[0025] Hereinafter, an operation example of the vertical Hall element 1 will be described with reference to FIG. 3. FIG. 3 shows the first semiconductor layer 20 through the magnetosensitive layer 30, and the side surface of the magnetosensitive layer 30 in the X direction is described perpendicular to the first surface 201 of the first semiconductor layer 20. Also, in FIG. 3, the illustration of the current constriction portion is omitted.

[0026] In order to detect a magnetic field by the vertical Hall element 1, a detection current Is flows between the first main electrode 401 and the second main electrode 402 through the first semiconductor layer 20. As described above, the detection current Is flows in a direction perpendicular to the first surface 201 of the first semiconductor layer 20 through the first magnetosensitive layer 301, and flows in a direction parallel to the first surface 201 of the first semiconductor layer 20. Electrical insulation of the substrate 10 with respect to the first semiconductor layer 20 is ensured so that the detection current Is does not flow through the substrate 10.

[0027] When a magnetic field Bx passes in a direction parallel to the main surface of the substrate 10 while the detection current Is is flowing through the first magnetosensitive layer 301 in a direction perpendicular to the first surface 201, a Lorentz force f is generated according to Fleming's left-hand rule by the detection current Is and the magnetic field Bx. Charged particles (carriers) accumulate in the direction of the Lorentz force f, and a Hall output voltage is generated due to the bias of the charged particles.

[0028] In the vertical Hall element 1, the Hall output voltage generated due to the Lorentz force f directed from the first Hall electrode 501 to the second Hall electrode 502 is detected by the Hall electrode 50. In the manner described above, the magnetic field Bx is detected by the vertical Hall element 1.

[0029] In the vertical Hall element 1, the second magnetosensitive layers 302 are respectively disposed on both sides of the first magnetosensitive layer 301. For this reason, the detection current Is is divided into a component flowing through the second magnetosensitive layer 302A and a component flowing through the second magnetosensitive layer 302B after flowing through the first magnetosensitive layer 301. In other words, in the vertical Hall element 1, a current path that flows from the first magnetosensitive layer 301 through the first semiconductor layer 20 to the second magnetosensitive layer 302A and a current path that flows from the first magnetosensitive layer 301 through the first semiconductor layer 20 to the second magnetosensitive layer 302B are formed.

[0030] Since there are two current paths of the detection current Is, the vertical Hall element 1 is prevented from erroneously detecting a magnetic field (hereinafter also referred to as "vertical magnetic field") passing in a direction perpendicular to the main surface of the substrate 10. For example, as shown in FIG. 4, when the magnetic field Bz passes in a direction perpendicular to the first surface 201, the Lorentz force fa acting on the component parallel to the first surface 201 of the detection current Is flowing through the first semiconductor layer 20 from the first magnetosensitive layer 301 toward the second magnetosensitive layer 302A and the Lorentz force fb acting on the component parallel to the first surface 201 of the detection current Is flowing through the first semiconductor layer 20 from the first magnetosensitive layer 301 toward the second magnetosensitive layer 302B are generated. At this time, as shown in FIG. 4, the directions of the Lorentz force fa and the Lorentz force fb are opposite. For this reason, the directions of the Hall output voltages respectively caused by the Lorentz force fa and the Lorentz force fb are symmetric and cancel each other out, and no Hall output voltage is generated. Therefore, only the magnetic field Bx passing in a direction parallel to the main surface of the substrate 10 is detected by the vertical Hall element 1.

[0031] In order to increase the sensitivity of the vertical Hall element 1, it is effective to increase the distance in which the detection current Is flows in the first magnetic sensing layer 301. That is, increasing the film thickness of the first magnetic sensing layer 301 is effective for increasing the sensitivity. The film thickness of the first magnetic sensing layer 301 is the length along the normal direction (Z direction) of the first surface 201 of the first semiconductor layer 20 from the upper surface to the bottom surface.

[0032] However, when forming the magnetic sensing layer 30 by etching the semiconductor film into a mesa shape, there is a limit to increasing the film thickness of the magnetic sensing layer 30. This is because the film thickness of the magnetic sensing layer 30 is restricted by the film forming apparatus. For example, when forming the magnetic sensing layer 30 by epitaxial growth method, if there is an upper limit of the growth film thickness in the epitaxial growth apparatus, there is a limit to increasing the film thickness of the magnetic sensing layer 30. Therefore, it is preferable to increase the sensitivity of the vertical Hall element 1 by a method other than increasing the film thickness of the magnetic sensing layer 30. Of course, it is also possible to form the magnetic sensing layer 30 by a manufacturing method without a film thickness limit.

[0033] Hereinafter, with reference to the magnetic sensing layer model 30M shown in FIG. 5, the sensitivity of the vertical Hall element 1 will be examined. The size of the magnetic sensing layer model 30M is the thickness L along the Z direction in which the detection current Is flows, the length t along the X direction in which the magnetic field B is directed, and the width W along the Y direction perpendicular to the thickness L and the length t. The thickness L corresponds to the film thickness of the magnetic sensing layer 30. The length t and the width W depend on the cross-sectional area of the region in which the detection current Is flows.

[0034] When the detection current Is and the magnetic field B are applied to the magnetic sensing layer model 30M, the carriers receive the Lorentz force of f = q × v × B. q is the charge of an electron and v is the drift velocity. A steady state is reached where the force F received from the electric field generated by the bias of the carriers due to the Lorentz force f balances the Lorentz force f. The force F received from the electric field is expressed by the following formula (1): F = q × (Vh / W) ···(1) In formula (1), Vh is the Hall output voltage. On the other hand, the detection current Is is expressed by formula (2): Is = q × n × v × W × t ···(2) In Equation (2), n is the carrier concentration.

[0035] When removing the drift velocity v in Equation (2) from f = F, the Hall output voltage Vh when driving the magnetosensitive layer model 30M with a constant current is expressed by the following Equation (3): Vh = I × B / (q × n × t) ···(3)

[0036] The Hall output voltage Vh when driving the vertical Hall element with a constant voltage is expressed by Equation (4) obtained by substituting the input voltage Vin = Rs × (L / W) × I when the sheet resistance of the magnetosensitive layer model 30M is Rs into Equation (3): Vh = μ × (W / L) × Vin × B ···(4) In Equation (4), μ is the carrier mobility. Also, the sheet resistance Rs = 1 / (q × n × μ × t).

[0037] The sensitivity Kh of the magnetosensitive layer model 30M is expressed by the following Equation (5) using the resistivity ρ: Kh = 1 / (q × n × t) = Rs × μ = ρ × μ / t ···(5)

[0038] Note that when the thickness L is short compared to the width W of the magnetosensitive layer 30, the sensitivity Kh is expressed by Equation (6) obtained by multiplying the sensitivity Kh shown in Equation (5) by the shape effect coefficient K: Kh = 1 / (q × n × t) × K ···(6) For example, when L >> W, K = 1, and when L < W, K = 0.74 × L / W.

[0039] The length t and the width W depend on the size of the main electrode 40, and the thickness L corresponds to the film thickness of the magnetosensitive layer 30. In the vertical Hall element 1 where the thickness L is short, it is preferable that the shape effect coefficient K does not affect the sensitivity Kh. Hereinafter, the improvement of the sensitivity Kh of the vertical Hall element 1 will be examined.

[0040] From Equation (5), it can be seen that in order to increase the sensitivity Kh, it is sufficient to decrease the carrier concentration n and the length t. Therefore, using Si as the material of the magnetosensitive layer 30 to decrease the carrier concentration n is effective for increasing the sensitivity Kh.

[0041] On the other hand, since compound semiconductors such as GaAs have a higher mobility μ compared to Si, the length t can be decreased. Therefore, by using a compound semiconductor as the material of the magnetosensitive layer 30, the length t can be decreased to increase the sensitivity Kh. For example, when the resistance value of the magnetosensitive layer 30 is determined, the length t may be decreased to increase the sensitivity Kh.

[0042] Since the sensitivity Kh depends on the carrier concentration n, by using a compound semiconductor for the magnetosensitive layer 30, a vertical Hall element 1 with less change in sensitivity with respect to temperature can be obtained. Also, by using a compound semiconductor with a lower resistance value than Si for the magnetosensitive layer 30, a vertical Hall element 1 having the same resistance value and temperature characteristics as a planar Hall element using a compound semiconductor may be realized.

[0043] In order to increase the sensitivity of the magnetosensitive layer model 30M, it is effective to decrease the length t and set L ≥ W. For example, by increasing the thickness L and decreasing the width W, the sensitivity of the magnetosensitive layer model 30M can be increased.

[0044] Incidentally, as shown in Expressions (5) and (6), the sensitivity Kh depends on the length t and width W of the magnetosensitive layer 30 along the direction in which the magnetic field is directed. Therefore, the size of the magnetosensitive layer 30 may be set according to the sensitivity required for the vertical Hall element 1. However, as shown in FIG. 6, in the magnetosensitive layer of the comparative example that does not include a current constriction portion (hereinafter referred to as "comparative magnetosensitive layer 301M"), the current path of the detection current Is flowing through the comparative magnetosensitive layer 301M spreads inside the comparative magnetosensitive layer 301M.

[0045] FIG. 7 shows an example of the spread of the current path of the detection current Is flowing through the comparative magnetosensitive layer 301M. In the example shown in FIG. 7, the length of the main electrode 40 in the X direction is 5 μm, and the length from the upper surface to the bottom surface of the comparative magnetosensitive layer 301M is 15 μm. The X-axis in FIG. 7 is the distance in the direction from the center of the main electrode 40 toward the side surface. The Y-axis in FIG. 7 is the distance from the upper surface to the bottom surface of the comparative magnetosensitive layer 301M. Also, the ratio (10% to 90%) of the detection current Is shown in FIG. 7 is the ratio with respect to the entire detection current Is flowing through the comparative magnetosensitive layer 301M. For example, focusing on the 90% graph, at a depth of 15 μm from the upper surface of the comparative magnetosensitive layer 301M, 90% of the detection current Is spreads in the range of about 20 μm in the X direction from the center.

[0046] When the current path of the detection current Is flowing through the magnetosensitive layer in the vertical Hall element spreads, the length t and width W increase, and the sensitivity decreases from Expressions (5) and (6). Therefore, suppressing the spread of the current path of the detection current Is is effective in improving the sensitivity of the vertical Hall element.

[0047] As already described, the first magnetosensitive layer 301 of the vertical Hall element 1 includes a current constriction portion. In the first magnetosensitive layer 301 of the vertical Hall element 1, as shown in FIG. 8, the detection current Is flows through the first region 321 in the current constriction portion and does not flow through the second region 322. Therefore, according to the vertical Hall element 1, the spread of the current path of the detection current Is in the first magnetosensitive layer 301 is suppressed.

[0048] As described above, in the vertical Hall element 1 according to the first embodiment, since the first magnetosensitive layer 301 includes a current constriction portion, the spread of the current path of the detection current Is is suppressed. Therefore, according to the vertical Hall element 1, the sensitivity can be improved.

[0049] Further, in the vertical Hall element 1 having the mesa-shaped magnetosensitive layer 30, by forming the mesa-shaped magnetosensitive layer 30, it is easy to configure a vertical Hall element using a material for which it is difficult to form the magnetosensitive layer as an embedded region in the semiconductor substrate or semiconductor layer. Also, the vertical Hall element 1 suppresses the generation of leakage current and parasitic capacitance as compared with, for example, a vertical Hall element having a configuration in which a p-type semiconductor region and an n-type semiconductor region are adjacent. Therefore, according to the vertical Hall element 1, a magnetic field can be detected with high accuracy.

[0050] By the way, when forming the mesa-shaped magnetosensitive layer 30 by etching the semiconductor film, there is a possibility that a magnetosensitive layer film of the material of the magnetosensitive layer 30 remains on the first surface 201 of the first semiconductor layer 20 in the remaining region excluding the region where the magnetosensitive layer 30 is formed. If the magnetosensitive layer film remains on the first surface 201 of the first semiconductor layer 20, a part of the detection current Is may flow between the first magnetosensitive layer 301 and the second magnetosensitive layer 302 via the magnetosensitive layer film. When the detection current Is flows through the magnetosensitive layer film, the resistance value of the detection current Is flowing parallel to the first surface 201 of the first semiconductor layer 20 increases, or a vertical magnetic field is detected, etc., and the sensitivity accuracy of the vertical Hall element 1 decreases.

[0051] Therefore, as shown in FIG. 9, the magnetosensitive layer 30 may be formed by over-etching to etch a part of the upper portion of the first semiconductor layer 20. By this over-etching, the magnetosensitive layer film does not remain in the remaining region of the first surface 201 excluding the region in contact with the mesa-shaped magnetosensitive layer 30.

[0052] In the vertical hall element 1 shown in Fig. 9, by forming the magnetosensitive layer 30 by over-etching, a convex portion is formed in the region where the bottom surface of the magnetosensitive layer 30 of the first semiconductor layer 20 comes into contact without being etched. Therefore, the vertical hall element 1 has a configuration in which the first magnetosensitive layer 301 and the second magnetosensitive layer 302 are disposed on the top surface of the convex portion formed on the first surface 201 of the first semiconductor layer 20.

[0053] Hereinafter, with reference to FIGS. 10A, 10B to 20A, and 20B, a method for manufacturing the vertical hall element 1 according to the first embodiment will be described. FIGS. 10A to 20A are plan views seen from the Z direction, and FIGS. 10B to 20B are cross-sectional views taken along the B-B direction of FIGS. 10A to 20A. Note that the method for manufacturing the vertical hall element 1 described below is an example, and including this modification example, it can be realized by various other manufacturing methods. Hereinafter, the case of forming the magnetosensitive layer 30 by over-etching described with reference to Fig. 9 will be described.

[0054] First, as shown in FIGS. 10A and 10B, for example, by an epitaxial growth method or the like, the first semiconductor layer 20 and the magnetosensitive layer film 300 are sequentially formed on the main surface of the substrate 10. At this time, as shown in FIG. 10B, in the region where the first magnetosensitive layer 301 is formed, a semiconductor film 320 is formed between the first semiconductor layer 20 and the magnetosensitive layer film 300. For example, a GaAs(n-GaAs) layer doped with an n-type impurity is formed as the first semiconductor layer 20 on the main surface of the GaAs substrate of the substrate 10. Then, a semiconductor film 320 of an AlAs film is formed in the region where the first magnetosensitive layer 301 of the first semiconductor layer 20 is formed. For example, after forming an AlAs film on the entire first surface 201 of the first semiconductor layer 20, the AlAs film may be patterned using photolithography technology to form the semiconductor film 320. Thereafter, an n-type impurity-doped GaAs(n-GaAs) film is formed as the magnetosensitive layer film 300 on the upper surface of the first semiconductor layer 20 so as to cover the semiconductor film 320. The n-type impurity is, for example, Si. The impurity concentration of the first semiconductor layer 20 is, for example, 1E17 cm + ~1E19 cm -3 ~1E19 cm -3and the film thickness is about 1 to 5 μm, for example. The impurity concentration of the magnetosensitive layer film 300 is, for example, 1E16 cm -3 ~1E17 cm -3 and the film thickness is about 15 μm, for example. The semiconductor film 320 is a conductive semiconductor having the same conductivity type as the magnetosensitive layer film 300 and may have an impurity concentration comparable to that of the magnetosensitive layer film 300.

[0055] Next, as shown in FIGS. 11A and 11B, a part of the magnetosensitive layer film 300 is selectively etched and removed to form a mesa-shaped magnetosensitive layer 30. At this time, as shown in FIG. 11B, by forming a groove between the mesa shapes (hereinafter referred to as "mesa groove 310") by overetching, a part of the upper part of the first semiconductor layer 20 from the first surface 201 is etched. For the etching of the magnetosensitive layer film 300, a dry etching method such as reactive ion etching (RIE) may be used.

[0056] After forming the magnetosensitive layer 30, the semiconductor film 320 is heat-treated in a steam atmosphere at 350 to 450 degrees by a selective oxidation technique to be selectively oxidized from the side direction, and an AlOx film is formed as the second region 322 as shown in FIG. 12B. The region where the semiconductor film 320 remains unoxidized is the first region 321. Then, as shown in FIGS. 12A and 12B, an insulating film 60 is formed on the upper surface of the magnetosensitive layer 30. The insulating film 60 may be, for example, a SiN film. Next, as shown in FIGS. 13A and 13B, the insulating film 60 in the region where the main electrode 40 and the hall electrode 50 are arranged is removed. For example, an opening 600 is provided in the insulating film 60 by photolithography technology and a dry etching method.

[0057] Thereafter, as shown in FIGS. 14A and 14B, the first metal film 410 is formed on the upper surface of the insulating film 60 so as to fill the opening 600 of the insulating film 60. At this time, the first metal film 410 is also formed on the wall surface of the mesa groove 310. For example, the first metal film 410 may be formed by laminating an AuGe film and a Ni film in this order.

[0058] After forming the first metal film 410, as shown in FIGS. 15A and 15B, the first metal film 410 is selectively removed so that only the regions of the main electrode 40 and the hole electrode 50 remain. Thereafter, the laminated film of the AuGe film and the Ni film may be made into an AuGe / Ni film by alloying through heat treatment.

[0059] Next, as shown in FIGS. 16A and 16B, a second metal film 420 is formed on the upper surface of the insulating film 60 and the wall surface of the mesa groove 310 so as to cover the upper surface of the first metal film 410. The second metal film 420 may be, for example, a TiAu film.

[0060] Next, as shown in FIGS. 17A and 17B, a third metal film 430 is formed on the upper surface of the second metal film 420 above the first metal film 410. The third metal film 430 may be, for example, Au plating. Thereafter, as shown in FIGS. 18A and 18B, the second metal film 420 is selectively removed except for the regions of the main electrode 40 and the hole electrode 50. Through the above steps, the main electrode 40 and the hole electrode 50 having a laminated structure of, for example, an AuGe / Ni film, a TiAu film, and Au plating are formed.

[0061] Thereafter, as shown in FIGS. 19A and 19B, the insulating film 60 of the dicing street portion, which is the outer edge portion of the vertical hole element 1, is removed. Next, as shown in FIGS. 20A and 20B, back lapping for polishing the lower surface of the substrate 10 is performed. Thereafter, the first semiconductor layer 20 and the substrate 10 are cut in the Z direction in the dicing street portion, and the vertical hole element 1 is diced into chips.

[0062] Through the above steps, a vertical hole element 1 is completed in which the bottom surface of the mesa-shaped first magnetosensitive layer 301 is in contact with the first surface 201 of the first semiconductor layer 20 and the current constriction portion divided into the first region 321 and the second region 322 is included in the first magnetosensitive layer 301. Since the first magnetosensitive layer 301 and the second magnetosensitive layer 302 are in direct contact with the first semiconductor layer 20, the electrical resistance of the detection current Is flowing in the direction perpendicular to the first surface 201 of the first semiconductor layer 20 can be reduced.

[0063] In the above description, a method of forming the semiconductor film 320 between the first semiconductor layer 20 and the magnetosensitive layer film 300 in the region where the first magnetosensitive layer 301 is formed has been exemplarily described. However, as shown in FIG. 21, the semiconductor film 320 may be formed over the entire surface between the first semiconductor layer 20 and the magnetosensitive layer film 300. Then, after forming the magnetosensitive layer 30, the semiconductor film 320 may be selectively oxidized from the side direction in each of the first magnetosensitive layer 301 and the second magnetosensitive layer 302 by a selective oxidation technique to form the second region 322. By the above process, as shown in FIG. 22, current constriction portions are formed in each of the first magnetosensitive layer 301 and the second magnetosensitive layer 302.

[0064] The carrier mobility of an n-type semiconductor into which n-type impurities are implanted can be made higher than that of a p-type semiconductor into which p-type impurities are implanted. For this reason, in the vertical hole element 1, it is preferable to use n-type impurities as the impurities of the semiconductor in order to increase the sensitivity to the magnetic field. Further, the detection current Is flowing parallel to the first surface 201 is not directly involved in the detection of the magnetic field B. For this reason, in order to reduce the electrical resistance of the detection current Is flowing parallel to the first surface 201, the impurity concentration of the first semiconductor layer 20 is made higher than the impurity concentration of the magnetosensitive layer 30.

[0065] As already described, since the directions of the Lorentz forces f generated with respect to the components of the detection current Is flowing through the second magnetosensitive layer 302A and the second magnetosensitive layer 302B are opposite to each other, it is possible to prevent the vertical magnetic field from being erroneously detected. Therefore, in order to make the components of the detection current Is flowing through the second magnetosensitive layer 302A and the second magnetosensitive layer 302B equal to each other, it is preferable that the electrical resistances of the current paths in the second magnetosensitive layer 302A and the current paths in the second magnetosensitive layer 302B are equal.

[0066] Therefore, the magnetosensitive layer 30 is formed such that the heights and cross-sectional areas of the second magnetosensitive layer 302A and the second magnetosensitive layer 302B are equal. The height of the magnetosensitive layer 30 is the size in the direction perpendicular to the first surface 201 of the first semiconductor layer 20, and the cross-sectional area is the area of the cross-section perpendicular to the height direction. Further, with respect to other mesa-shaped parameters that affect the electrical resistance of the second magnetosensitive layer 302, such as the inclination of the side surface with respect to the first surface 201, the widths of the bottom surface and the top surface, etc., it is preferable that they are made equal between the second magnetosensitive layer 302A and the second magnetosensitive layer 302B.

[0067] In forming the magnetosensitive layer 30, for example, a silicon oxide film or a photoresist film patterned by photolithography technology may be used as an etching mask. By using a silicon oxide film or the like having a higher hardness than the photoresist film as an etching mask, the shape stability of the etching mask can be improved.

[0068] Each side surface of the magnetosensitive layer 30 may extend in a direction perpendicular to the first surface 201 of the first semiconductor layer 20, or may extend in a direction intersecting obliquely with the first surface 201. For example, as shown in FIG. 23, by extending the side surface of the magnetosensitive layer 30 perpendicular to the first surface 201 of the first semiconductor layer 20, the size of the vertical hole element 1 as viewed from the Z direction can be reduced.

[0069] Incidentally, the size of the main electrode 40 is limited by the lower limit of the manufacturing limit in the electrode process design. Also, in order to electrically connect the main electrode 40 to an external power source, for example, by wire bonding or the like, a certain area is required for the main electrode 40. Therefore, as shown in FIG. 24, a main electrode 40 having an area required for wire bonding or the like is formed on the upper surface of the insulating film 60 formed on the upper surface of the magnetosensitive layer 30, and the main electrode 40 and the magnetosensitive layer 30 may be brought into contact at the opening 600 of the insulating film 60. In other words, the size of the opening 600 of the insulating film 60 (hereinafter, "pitch size D") is designed to correspond to the size of the magnetosensitive layer 30 according to the required sensitivity.

[0070] As described above, it is preferable to form the insulating film 60 on the upper surface of the magnetosensitive layer 30 and electrically connect the main electrode 40 to the magnetosensitive layer 30 through the opening 600 provided in the insulating film 60. The aperture size D of the opening 600 of the insulating film 60 is preferably set in consideration of the size of the magnetosensitive layer 30 that affects the sensitivity Kh of the vertical Hall element 1, the size of the main electrode 40, and the relationship between the aperture size D. The aperture size D and the width of the first region 321 of the current constriction portion are the substantial sizes of the main electrode 40 of the vertical Hall element 1 that affect the sensitivity Kh.

[0071] <First Modified Example> In the above, a configuration in which a pair of second magnetosensitive layers 302 are arranged with the first magnetosensitive layer 301 interposed therebetween was shown. As already described, it is preferable that the current paths of the detection current Is are symmetrically configured along the direction in which the magnetic field Bx passes so as not to erroneously detect the vertical magnetic field. For this reason, the detection current Is may be branched into two or more in a symmetric manner with respect to the first magnetosensitive layer 301. In other words, if the symmetry of the detection current Is is maintained, the number of the second magnetosensitive layers 302 may be other than two.

[0072] For example, as shown in FIG. 25A, there may be a plurality of pairs of second magnetosensitive layers 302 arranged on both sides of the first magnetosensitive layer 301. Alternatively, as shown in FIG. 25B, the vertical Hall element 1 may include a plurality of electromagnetic layer units 30A having a configuration in which a pair of second magnetosensitive layers 302 are arranged with the first magnetosensitive layer 301 interposed therebetween.

[0073] According to the vertical Hall element 1 shown in FIGS. 25A and 25B, a large detection current Is can be passed to improve the sensitivity. In addition, by increasing the current paths of the detection current Is, the electrical resistance of the current paths can be reduced. For this reason, the degree of freedom in design regarding the detection current Is can be increased.

[0074] In FIG. 25A, a configuration is shown in which there are two pairs of the second magnetosensitive layers 302 sandwiching the first magnetosensitive layer 301, but there may be three or more pairs of the second magnetosensitive layers 302. In FIG. 25B, a configuration is shown in which the vertical Hall element 1 includes two electromagnetic layer units 30A, but the number of the electromagnetic layer units 30A may be three or more.

[0075] <Second Modification Example> In FIG. 1, a configuration is shown in which the current constriction portion divided into the first region 321 and the second region 322 is at one location between the bottom surface and the top surface of the first magnetosensitive layer 301. However, a plurality of current constriction portions may be arranged at intervals from each other between the bottom surface and the top surface of the first magnetosensitive layer 301. For example, as shown in FIG. 26, the current constriction portions may be arranged at three locations between the bottom surface and the top surface of the first magnetosensitive layer 301. By arranging a plurality of current constriction portions in multiple stages in the first magnetosensitive layer 301, the spread of the current path of the detection current Is can be more reliably suppressed. Note that the widths of the first regions 321 may be the same for each current constriction portion, or may be different from each other. For example, the width of the first region 321 of the current constriction portion may be widened as it is closer to the top surface of the first magnetosensitive layer 301, and narrowed as it is closer to the bottom surface.

[0076] <Third Modification Example> The vertical Hall element 1 according to the third modification example shown in FIG. 27 further includes a second semiconductor layer 70 disposed between the magnetosensitive layer 30 and the first surface 201 of the first semiconductor layer 20. The second semiconductor layer 70 is a semiconductor layer made of a material having a different composition from that of the magnetosensitive layer 30. The second semiconductor layer 70 functions as an etching stop layer in the process of etching the magnetosensitive layer film 300 to form the mesa groove 310.

[0077] Hereinafter, with reference to the drawings, a manufacturing method of the vertical Hall element 1 according to the third modification example will be described.

[0078] First, a first semiconductor layer 20 is formed on the upper surface of a substrate 10. Next, a second semiconductor layer 70 is formed on a first surface 201 of the first semiconductor layer 20 by, for example, an epitaxial growth method or the like. Then, after forming a semiconductor film 320 in a region where a first magnetosensitive layer 301 is to be formed, a magnetosensitive layer film 300 is formed on the upper surface of the second semiconductor layer 70 so as to cover the semiconductor film 320 as shown in FIG. 28. The second semiconductor layer 70 is a material having an etching rate lower than that of the magnetosensitive layer film 300.

[0079] For example, when the magnetosensitive layer film 300 is a GaAs film doped with an n-type impurity, the second semiconductor layer 70 may be a phosphorus (P)-based compound semiconductor such as InGaP doped with an n-type impurity. The film thickness of the second semiconductor layer 70 is, for example, about 10 nm or less.

[0080] Thereafter, a mesa-shaped magnetosensitive layer 30, a main electrode 40, and a Hall electrode 50 are formed in the same manner as the above-described steps described with reference to FIGS. 11A, 11B to 20A, and 20B.

[0081] However, unlike the steps described with reference to FIGS. 11A and 11B, in the step of etching the magnetosensitive layer film 300 to form a mesa groove 310, the second semiconductor layer 70 functions as an etching stop layer. For this reason, as shown in FIG. 27, a vertical Hall element 1 having a configuration in which the second semiconductor layer 70 is disposed on the first surface 201 of the first semiconductor layer 20 is completed. By using the second semiconductor layer 70 as an etching stop layer, it is possible to sufficiently etch the magnetosensitive layer film 300 without considering that the upper portion of the first semiconductor layer 20 is etched due to over-etching of the magnetosensitive layer film 300. Thereby, it is possible to prevent the magnetosensitive layer film 300 from remaining on the first surface 201 of the first semiconductor layer 20 between the first magnetosensitive layer 301 and the second magnetosensitive layer 302.

[0082] In the manufacturing process of the vertical hall element 1 shown in FIG. 27, the mesa groove 310 may be formed in two steps of a dry etching method and a wet etching method. For example, after etching the magnetosensitive layer film 300 to a certain depth using the dry etching method, the magnetosensitive layer film 300 may be etched using the wet etching method until the second semiconductor layer 70 is exposed. Thereby, while shortening the etching time using the dry etching method, the second semiconductor layer 70 can be used as an etching stop layer of the wet etching method.

[0083] The film thickness of the second semiconductor layer 70 may be as thin as, for example, about 10 nm. Therefore, the electrical resistance of the current flowing through the second semiconductor layer 70 in parallel with the first surface 201 of the first semiconductor layer 20 is high, and it is possible to suppress the detection current Is from flowing in parallel with the first surface 201 through the second semiconductor layer 70. As a result, the current path of the detection current Is flowing between the first magnetosensitive layer 301 and the second magnetosensitive layer 302 can be limited to the first semiconductor layer 20. After the magnetosensitive layer 30 is formed, a part of the second semiconductor layer 70 may be removed so as to expose the first surface 201 of the first semiconductor layer 20.

[0084] In the above, the case where the second semiconductor layer 70 is used as an etching stop layer in the process of forming the magnetosensitive layer 30 has been described. The second semiconductor layer 70 may be used for end point detection (End Point Detection; EPD) in etching by the dry etching method.

[0085] For example, in the etching process of the magnetosensitive layer film 300 by the dry etching method, by detecting the change in the reflectivity of light due to the difference in the composition elements of the magnetosensitive layer film 300 and the second semiconductor layer 70, it is possible to detect the end point of etching. When the magnetosensitive layer film 300 is a GaAs film, by using the second semiconductor layer 70 as an InGaP film, the end point of the etching process can be detected by the change in the reflectivity of light.

[0086] (Second Embodiment) As shown in FIG. 29, in the vertical Hall element 1 according to the second embodiment, a laminate 330 in which a first layer 331 and a second layer 332 are laminated on a first magnetosensitive layer 301 is formed. The laminate 330 is a tunnel junction region in which the first layer 331 of the first conductivity type semiconductor region and the second layer 332 of the second conductivity type semiconductor region are laminated. For example, the first layer 331 is a p-type semiconductor region, and the second layer 332 is an n-type semiconductor region. In this case, the first semiconductor layer 20 needs to be a p-type semiconductor. The vertical Hall element 1 shown in FIG. 29 includes a structure in which an n-type semiconductor layer (first magnetosensitive layer 301), an n+-type semiconductor layer (second layer 332), a p+-type semiconductor layer (first layer 331), and a p-type semiconductor layer (first semiconductor layer 20) are arranged in this order from the upper surface to the bottom surface of the first magnetosensitive layer 301.

[0087] The impurity concentration of the laminate 330 is set higher than that of other regions of the first magnetosensitive layer 301. For example, the impurity concentration of the first magnetosensitive layer 301 is 1E16 cm -3 ~1E17 cm -3 On the other hand, the first layer 331 is, for example, a p-type semiconductor region having a film thickness of about 15 nm and an impurity concentration of about 1E20 cm -3 with impurities such as carbon (C). The second layer 332 is, for example, an n-type semiconductor region having a film thickness of about 15 nm and an impurity concentration of about 1E19 cm -3 with impurities such as Te. Therefore, the laminate 330 of the tunnel junction region functions as the first region 321 of the current constriction portion, and the region sandwiching the laminate 330 of the first magnetosensitive layer 301 functions as the second region 322.

[0088] As described above, the vertical Hall element 1 according to the second embodiment is different from the vertical Hall element 1 according to the first embodiment in that the first region 321 of the current constriction portion is constituted by a tunnel junction region. Regarding other configurations, the second embodiment is the same as the first embodiment shown in FIG. 1.

[0089] In the vertical Hall element 1 including the first region 321 which is a tunnel junction region in which the first layer 331 and the second layer 332 each having an impurity concentration higher than that of the second region 322 are stacked, the spread of the current path of the detection current Is is suppressed.

[0090] Others, the vertical Hall element 1 according to the second embodiment is substantially the same as the first embodiment, and redundant descriptions are omitted. For example, as shown in FIG. 25A, a plurality of pairs of the second magnetic sensing layers 302 disposed on both sides of the first magnetic sensing layer 301 may be provided. Alternatively, as shown in FIG. 25B, a plurality of electromagnetic layer units 30A having a configuration in which a pair of second magnetic sensing layers 302 are disposed with the first magnetic sensing layer 301 interposed therebetween may be included. Further, as shown in FIG. 27, a second semiconductor layer 70 may be further provided as an etching stop layer between the magnetic sensing layer 30 and the first semiconductor layer 20. Further, a current constriction portion including a tunnel junction region may also be formed in the second magnetic sensing layer 302.

[0091] (Third Embodiment) As shown in FIG. 30, in the vertical Hall element 1 according to the third embodiment, the second region 322 is continuously formed in the outer edge region of the first magnetic sensing layer 301 from the upper surface to a certain range. The region inside the second region 322 of the first magnetic sensing layer 301 is the first region 321. The vertical Hall element 1 according to the third embodiment is different from the vertical Hall element 1 according to the first embodiment in that the second region 322 of the current constriction portion is formed at a certain depth in the outer edge region of the first magnetic sensing layer 301. Regarding other configurations, the third embodiment is the same as the first embodiment shown in FIG. 1.

[0092] The second region 322 of the vertical Hall element 1 shown in FIG. 30 is an insulating region where the detection current Is does not flow. For example, the crystal structure of the outer edge region of the first magnetic sensing layer 301 may be destroyed by ion implantation of hydrogen (H), argon (Ar), helium (He), etc. to form the second region 322. In other words, the second region 322 may be made a region having more crystal defects than the first region 321 to suppress the spread of the current path of the detection current Is.

[0093] FIG. 30 shows an example in which the region from the upper surface to the middle of the bottom surface of the first magnetosensitive layer 301 is the second region 322, but the range from the upper surface of the second region 322 can be arbitrarily set. The closer the position of the lower surface of the second region 322 is to the bottom surface of the first magnetosensitive layer 301, the more the spread of the current path of the detection current Is can be suppressed. For example, the second region 322 may be continuously formed from the upper surface to the bottom surface of the first magnetosensitive layer 301.

[0094] In the vertical hall element 1 shown in FIG. 30, the width of the first region 321 sandwiched between the second regions 322 is constant. However, the width of the first region 321 sandwiched between the second regions 322 may be changed between the upper surface and the bottom surface of the first magnetosensitive layer 301. For example, as shown in FIG. 31, the width of the first region 321 may be gradually narrowed from the upper surface toward the bottom surface.

[0095] Other than that, the vertical hall element 1 according to the third embodiment is substantially the same as the first embodiment, and redundant descriptions are omitted. For example, as shown in FIG. 25A, there may be a plurality of pairs of the second magnetosensitive layers 302 arranged on both sides of the first magnetosensitive layer 301. Alternatively, as shown in FIG. 25B, a plurality of electromagnetic layer units 30A having a configuration in which a pair of second magnetosensitive layers 302 are arranged with the first magnetosensitive layer 301 interposed therebetween may be included. Further, as shown in FIG. 27, a second semiconductor layer 70 may be further provided as an etching stop layer between the magnetosensitive layer 30 and the first semiconductor layer 20. Also, a current constriction portion may be formed at a certain depth in the outer edge region of the second magnetosensitive layer 302.

[0096] <Modification example> FIG. 30 shows a configuration in which a second region 322 formed in the outer edge region of the first magnetosensing layer 301 is an insulating region. In the vertical hole element 1 according to the modified example shown in FIG. 32, a third region 323 having a conductivity type different from that of the first region 321 of the first magnetosensing layer 301 is formed in the outer edge region of the first magnetosensing layer 301. In other words, a current constriction portion is formed in which the first region 321 is a first conductivity type semiconductor region and the third region 323 is a second conductivity type semiconductor region. When the first region 321 is an n-type semiconductor region, the third region 323 is a p-type semiconductor region. For example, p-type impurities such as zinc (Zn) and magnesium (Mg) are implanted into the outer edge region of the first magnetosensing layer 301 by an ion implantation method to form the third region 323 of the p-type semiconductor region. The third region 323 may be formed by using a thermal diffusion method instead of the ion implantation method.

[0097] In the vertical hole element 1 shown in FIG. 32, a depletion layer is formed as the second region 322 between the first region 321 and the third region 323. By forming a depletion layer outside the first region 321, the detection current Is flowing through the first region 321 does not spread beyond the depletion layer, and the spread of the current path of the detection current Is is suppressed.

[0098] (Other Embodiments) Although described by way of embodiments as above, it should not be understood that the discussions and drawings forming a part of this disclosure limit the embodiments. Various alternative embodiments, examples and operation techniques will be apparent to those skilled in the art from this disclosure.

[0099] For example, above, the vertical hole element 1 having a configuration in which the second main electrode 402 is disposed on the upper surfaces of a pair of second magnetosensing layers 302 disposed with the first magnetosensing layer 301 therebetween has been described. However, the vertical hole element 1 may not include the second magnetosensing layer 302. For example, as shown in FIG. 33, the second main electrode 402A and the second main electrode 402B may be directly disposed on the first surface 201 of the first semiconductor layer 20 at positions separated from the first magnetosensing layer 301 with the first magnetosensing layer 301 therebetween.

[0100] The vertical Hall element 1 shown in FIG. 33 is different from the vertical Hall element 1 according to the first embodiment in that it does not include the second magnetosensitive layer 302, but is otherwise substantially the same as the first embodiment. For example, there may be a plurality of pairs of second main electrodes 402 disposed on both sides of the first magnetosensitive layer 301. Alternatively, it may include a plurality of units configured to dispose a pair of second main electrodes 402 with the first magnetosensitive layer 301 interposed therebetween. Further, as shown in FIG. 27, a second semiconductor layer 70 may be further provided as an etching stop layer between the first magnetosensitive layer 301 and the first semiconductor layer 20. Further, a plurality of current constriction portions may be arranged to be spaced apart from each other between the bottom surface and the top surface of the first magnetosensitive layer 301. Alternatively, the vertical Hall element 1 in which the first region 321 is a tunnel junction region may not include the second magnetosensitive layer 302, similar to the second embodiment. Further, the vertical Hall element 1 in which the second region 322 is formed at a certain depth in the outer edge region of the first magnetosensitive layer 301 may not include the second magnetosensitive layer 302, similar to the third embodiment.

[0101] As described above in detail about the present disclosure, it is clear to those skilled in the art that the present disclosure is not limited to the embodiments described in the present disclosure. One or more elements of one embodiment can be combined with one or more elements of another embodiment. The present disclosure can be implemented as modified and changed aspects without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the description of the present disclosure is for illustrative purposes and has no restrictive meaning for the present disclosure.

[0102] [Appendix] The technical idea that can be grasped from the present disclosure is described below. Note that, for the purpose of assisting understanding rather than limiting, the components described in the appendix are assigned the reference numerals of the corresponding components in the embodiments. The reference numerals are shown as examples for assisting understanding, and the components described in each appendix should not be limited to the components indicated by the reference numerals.

[0103] (Appendix 1) The vertical Hall element 1 includes a conductive first semiconductor layer 20 defined on both sides by a first surface 201 and a second surface 202 facing each other, and a first magnetosensitive layer 301 of a mesa-shaped conductive semiconductor disposed above the first surface 201 of the first semiconductor layer 20 and having a bottom surface facing the first surface 201. At least a part from the bottom surface to the upper surface facing the bottom surface of the first magnetosensitive layer 301, a cross-section parallel to the bottom surface is divided into a first region 321 and a second region 322 having lower conductivity than the first region 321. According to the vertical Hall element 1 described in Appendix 1, since the detection current Is flows through the first region 321 and does not flow through the second region 322 in the first magnetosensitive layer 301, the spread of the current path of the detection current Is can be suppressed.

[0104] (Appendix 2) In the vertical Hall element 1 described in Appendix 1, the second region 322 is disposed sandwiching the first region 321. According to the vertical Hall element 1 described in Appendix 2, the detection current Is can flow in a direction perpendicular to the bottom surface in the first magnetosensitive layer 301.

[0105] (Appendix 3) In the vertical Hall element 1 described in Appendix 1 or 2, the second region 322 is formed of an insulating material. According to the vertical Hall element 1 described in Appendix 3, a current constriction portion where the detection current Is flows through the first region 321 can be formed in the first magnetosensitive layer 301.

[0106] (Appendix 4) In the vertical Hall element 1 described in Appendix 1 or 2, the first region 321 is a tunnel junction region in which a first layer 331 of a first conductivity type semiconductor region and a second layer 332 of a second conductivity type semiconductor region, each having a higher impurity concentration than the second region 322, are stacked. According to the vertical Hall element 1 described in Appendix 4, a current constriction portion where the detection current Is flows through the first region 321, which is a tunnel junction region, can be formed in the first magnetosensitive layer 301.

[0107] (Appendix 5) In the vertical Hall element 1 described in Supplementary Note 1 or 2, the second region 322 is continuously formed in the outer edge region of the first magnetosensitive layer 301 up to a certain range from the upper surface. According to the vertical Hall element 1 described in Supplementary Note 5, the first magnetosensitive layer 301 can be configured with a current constriction portion through which the detection current Is flows in the first region 321 which is a region excluding the outer edge region.

[0108] (Supplementary Note 6) In the vertical Hall element 1 described in Supplementary Note 5, the second region 322 is a region having more crystal defects than the first region 321. According to the vertical Hall element 1 described in Supplementary Note 6, by forming the second region 322 in which the crystal structure is destroyed in the outer edge region, the first magnetosensitive layer 301 can be configured with a current constriction portion.

[0109] (Supplementary Note 7) In the vertical Hall element 1 described in Supplementary Note 5, the first region 321 is a first conductivity type semiconductor region, and the second region 322 is a depletion layer formed between the second conductivity type semiconductor region formed in the outer edge region and the first region 321. According to the vertical Hall element 1 described in Supplementary Note 7, the first magnetosensitive layer 301 can be configured with a current constriction portion in which a depletion layer is formed outside the first region 321.

[0110] (Supplementary Note 8) In the vertical Hall element 1 described in any one of Supplementary Notes 1 to 3 or Supplementary Notes 5 to 7, a plurality of portions divided into the first region 321 and the second region 322 are arranged separately from each other between the bottom surface and the upper surface of the first magnetosensitive layer 301. According to the vertical Hall element 1 described in Supplementary Note 8, by forming a plurality of current constriction portions in multiple stages in the first magnetosensitive layer 301, the spread of the current path of the detection current Is can be more reliably suppressed.

[0111] (Supplementary Note 9) In the vertical Hall element 1 according to any one of Supplementary Notes 1 to 8, it further includes a first main electrode 401 disposed on the upper surface of the first magnetosensitive layer 301, and a second main electrode 402 disposed above the first surface 201 at a position separated from the first magnetosensitive layer 301. According to the vertical Hall element 1 described in Supplementary Note 9, with the first main electrode 401 as the first end of the current path and the second main electrode 402 as the second end of the current path, the detection current Is flows in a direction perpendicular to the main surface of the substrate 10.

[0112] (Supplementary Note 10) In the vertical Hall element 1 described in Supplementary Note 9, it further includes a pair of Hall electrodes 50 disposed on the upper surface of the first magnetosensitive layer 301 with the first main electrode 401 interposed therebetween. According to the vertical Hall element 1 described in Supplementary Note 10, the Hall output voltage caused by the Lorentz force f generated by the magnetic field in the direction parallel to the first surface 201 of the first semiconductor layer 20 and the detection current Is flowing through the first magnetosensitive layer 301 can be detected by the Hall electrodes 50.

[0113] (Supplementary Note 11) In the vertical Hall element 1 described in Supplementary Note 9 or 10, it further includes a second magnetosensitive layer 302 of a mesa-shaped conductive semiconductor disposed above the first surface 201 of the first semiconductor layer 20 at a position separated from the first magnetosensitive layer 301, and the bottom surface thereof faces the first surface 201. In the vertical Hall element 1 described in Supplementary Note 11, the second main electrode 402 is disposed on the upper surface of the mesa-shaped second magnetosensitive layer 302.

[0114] (Supplementary Note 12) In the vertical Hall element 1 described in Supplementary Note 11, two second magnetosensitive layers 302 are disposed with the first magnetosensitive layer 301 interposed therebetween. According to the vertical Hall element 1 described in Supplementary Note 12, since there are two current paths of the detection current Is, it is possible to prevent erroneously detecting a magnetic field passing in a direction perpendicular to the main surface of the substrate 10.

[0115] (Supplementary Note 13) In the vertical Hall element 1 described in any one of Supplementary Notes 1 to 12, the bottom surface of the first magnetosensitive layer 301 is in contact with the first surface 201 of the first semiconductor layer 20. According to the vertical Hall element 1 described in Supplementary Note 13, since the first magnetosensitive layer 301 is in direct contact with the first semiconductor layer 20, the electrical resistance of the detection current Is flowing in the direction perpendicular to the first surface 201 of the first semiconductor layer 20 can be reduced.

[0116] (Supplementary Note 14) In the vertical Hall element 1 described in Supplementary Note 13, the first magnetosensitive layer 301 is disposed on the top surface of the convex portion formed on the first surface 201 of the first semiconductor layer 20. In the vertical Hall element 1 described in Supplementary Note 14, by forming the magnetosensitive layer 30 by overetching so that a convex portion is formed on the first surface 201 of the first semiconductor layer 20, the magnetosensitive layer film 300 does not remain in the remaining region of the first surface 201 except for the region in contact with the magnetosensitive layer 30.

[0117] (Supplementary Note 15) In the vertical Hall element 1 described in any one of Supplementary Notes 1 to 12, a second semiconductor layer 70 having a composition different from that of the first magnetosensitive layer 301 is further provided between the first magnetosensitive layer 301 and the first surface 201 of the first semiconductor layer 20. In the vertical Hall element 1 described in Supplementary Note 15, the magnetosensitive layer film 300 does not remain between the first magnetosensitive layer 301 and the first semiconductor layer 20. Therefore, it is possible to prevent the detection current Is from flowing through the magnetosensitive layer film 300 formed on the surface of the first semiconductor layer 20.

[0118] (Supplementary Note 16) In the vertical Hall element 1 described in Supplementary Note 15, the etching rate of the second semiconductor layer 70 is lower than that of the first magnetosensitive layer 301. According to the vertical Hall element 1 of Supplementary Note 16, by using the second semiconductor layer 70 as an etching stop layer, it is possible to prevent the magnetosensitive layer film 300 from remaining on the first surface 201 of the first semiconductor layer 20.

[0119] (Supplementary Note 17) In the vertical Hall element 1 described in any one of Supplementary Notes 1 to 16, the material of the first region 321 of the first magnetic-sensitive layer 301 contains a compound semiconductor. According to the vertical Hall element 1 described in Supplementary Note 17, since the material of the first region 321 is a compound semiconductor, a vertical Hall element 1 with high sensitivity and good temperature characteristics with less change in sensitivity with respect to temperature compared to the case where the material of the first region 321 is silicon can be obtained.

[0120] (Supplementary Note 18) In the vertical Hall element 1 described in Supplementary Note 17, the material of the first region 321 of the first magnetic-sensitive layer 301 contains gallium arsenide. Since the material of the first region 321 is the compound semiconductor gallium arsenide, a vertical Hall element 1 with high sensitivity and good temperature characteristics can be obtained.

[0121] (Supplementary Note 19) The vertical Hall element 1 described in any one of Supplementary Notes 1 to 18 further includes an insulating substrate 10 connected to the second surface 202 of the first semiconductor layer 20. In the vertical Hall element 1 described in Supplementary Note 19, electrical insulation of the substrate 10 with respect to the first semiconductor layer 20 is ensured, and the detection current Is does not flow through the substrate 10.

Explanation of Reference Signs

[0122] 1 Vertical Hall element 10 Substrate 20 First semiconductor layer 60 Insulating film 70 Second semiconductor layer 201 First surface 202 Second surface 301 First magnetic-sensitive layer 302A, 302B Second magnetic-sensitive layer 320 Semiconductor film 321 First region 322 Second region 330 Laminate 331 First layer 332 Second layer 401 First main electrode 402A, 402B Second main electrodes 501 First Hall electrode 502 Second Hole Electrode

Claims

1. A conductive first semiconductor layer having a first surface and a second surface that face each other and define both surfaces, A first magnetosensitive layer of a mesa-shaped conductive semiconductor disposed above the first surface of the first semiconductor layer and having a bottom surface facing the first surface, Comprising, A vertical Hall element in which, in at least a part from the bottom surface to the upper surface of the first magnetosensitive layer, a cross section parallel to the bottom surface is divided into a first region and a second region having lower conductivity than the first region.

2. The vertical Hall element according to claim 1, wherein the second region is disposed with the first region interposed therebetween.

3. The vertical Hall element according to claim 1 or 2, wherein the second region is made of an insulating material.

4. The vertical Hall element according to claim 1 or 2, wherein the first region is a tunnel junction region in which a first layer of a first conductivity type semiconductor region having a higher impurity concentration than the second region and a second layer of a second conductivity type semiconductor region are stacked.

5. The vertical Hall element according to claim 1 or 2, wherein the second region is continuously formed in an outer edge region of the first magnetosensitive layer up to a certain range from the upper surface.

6. The vertical Hall element according to claim 5, wherein the second region is a region having more crystal defects than the first region.

7. The first region is a first conductivity type semiconductor region, The vertical Hall element according to claim 5, wherein the second region is a depletion layer formed between a second conductivity type semiconductor region formed in the outer edge region and the first region.

8. The vertical Hall element according to claim 1 or 2, wherein a plurality of portions divided into the first region and the second region are arranged separately from each other between the bottom surface and the upper surface of the first magnetosensitive layer.

9. A first main electrode disposed on the upper surface of the first magnetosensitive layer, A second main electrode disposed above the first surface at a position separated from the first magnetosensitive layer, The vertical Hall element according to claim 1 or 2, further comprising.

10. Further comprising a pair of Hall electrodes disposed on the upper surface of the first magnetosensitive layer with the first main electrode interposed therebetween, The vertical Hall element according to claim 9, wherein a Hall output voltage caused by a Lorentz force generated by a magnetic field in a direction parallel to the first surface of the first semiconductor layer and a detection current flowing between the first main electrode and the second main electrode via the first region of the first magnetosensitive layer is configured to be detectable by the Hall electrodes.

11. A second magnetosensitive layer, which is a mesa-shaped conductive semiconductor, is further provided above the first surface at a position separated from the first magnetosensitive layer, and the bottom surface thereof faces the first surface. The second main electrode is disposed on the upper surface of the second magnetosensitive layer facing the bottom surface. The vertical Hall element according to claim 9.

12. The vertical Hall element according to claim 11, wherein two of the second magnetosensitive layers are disposed with the first magnetosensitive layer interposed therebetween.

13. The vertical Hall element according to claim 1 or 2, wherein the bottom surface of the first magnetosensitive layer is in contact with the first surface of the first semiconductor layer.

14. The vertical Hall element according to claim 13, wherein the first magnetosensitive layer is disposed on the top surface of the convex portion formed on the first surface of the first semiconductor layer.

15. The vertical Hall element according to claim 1 or 2, further comprising a second semiconductor layer having a composition different from that of the first magnetosensitive layer, the second semiconductor layer being disposed between the first magnetosensitive layer and the first surface of the first semiconductor layer.

16. The vertical Hall element according to claim 15, wherein the second semiconductor layer has an etching rate lower than that of the first magnetosensitive layer.

17. The vertical Hall element according to claim 1 or 2, wherein the material of the first region of the first magnetosensitive layer includes a compound semiconductor.

18. The vertical Hall element according to claim 17, wherein the material of the first region of the first magnetosensitive layer includes gallium arsenide.

19. The vertical Hall element according to claim 1 or 2, further comprising an insulating substrate connected to the second surface of the first semiconductor layer.

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