CN108028314B

CN108028314B - Hall element, Hall sensor and lens module

Info

Publication number: CN108028314B
Application number: CN201680055543.0A
Authority: CN
Inventors: 古屋贵明; 赤木刚
Original assignee: Asahi Kasei Microdevices Corp
Current assignee: Asahi Kasei Microdevices Corp
Priority date: 2015-09-24
Filing date: 2016-09-21
Publication date: 2021-08-13
Anticipated expiration: 2036-09-21
Also published as: CN108028314A; JPWO2017051829A1; WO2017051829A1; JP6612887B2

Abstract

Provided are a Hall element, a Hall sensor and a lens module, wherein the variation of the offset voltage of the Hall element can be suppressed. The disclosed device is provided with: a substrate (10); a magnetism sensing unit (20) formed on the upper surface (10a) side of the substrate (10); a first electrode (31) and a second electrode (32), the first electrode (31) and the second electrode (32) being formed on the upper surface (10a) side and electrically connected to the magnetism sensing portion (20), the first electrode (31) and the second electrode (32) facing each other in a first direction; and a third electrode (33) and a fourth electrode (34), wherein the third electrode (33) and the fourth electrode (34) are formed on the upper surface (10a) side and are electrically connected to the magnetism sensing section (20), and the third electrode (33) and the fourth electrode (34) face each other in a second direction intersecting the first direction in plan view. The first electrode (31), the second electrode (32), the third electrode (33), and the fourth electrode (34) extend from the peripheral region of the magnetism sensing portion (20) to the central region of the magnetism sensing portion (20).

Description

Hall element, Hall sensor and lens module

Technical Field

The invention relates to a Hall element, a Hall sensor and a lens module.

Background

Conventionally, magnetic sensors have been applied to a large number of magnetic sensor products such as current detection devices and position detection devices. A hall element using the hall effect is a typical example of the magnetic sensor.

In general, a hall element includes a magnetism sensing portion, a current electrode pair for causing a current to flow through the magnetism sensing portion, and an output electrode pair for detecting a hall electromotive force, and detects the magnitude and direction of a magnetic force applied to the magnetism sensing portion from the hall electromotive force detected by the output electrode pair.

Patent document 1 discloses a hall element including: the semiconductor device includes a semi-insulating GaAs substrate, an N-type operating layer, an N + contact layer, an ohmic-bonding metal film, a bonding metal film, and an insulating film.

Patent document 2 discloses a hall element including: the inner corners of the four positions of the cross hall element are not formed at right angles, but are formed at oblique angles.

Patent document 3 discloses a hall sensor including: the semiconductor device includes a die, a plurality of lead terminals disposed around the die, a plurality of fine metal wires electrically connecting a plurality of electrode portions of the die and the lead terminals, respectively, an insulating paste covering a rear surface of the die, and a molding resin covering the die and the plurality of fine metal wires, wherein at least a portion of the insulating paste and at least a portion of the rear surface of each of the lead terminals are exposed from the molding resin, respectively.

Patent document 4 discloses a hall sensor including: the Hall sensor uses a Hall chip in which a cross-shaped magnetic induction part is formed on a substrate and electrodes are respectively formed on the cross-shaped arms, opposite parts between adjacent electrodes are parallel, and the parallel length of the opposite parts is set to be more than or equal to a value obtained by subtracting the distance between the opposite parts from 40 mu m.

Patent document 1: japanese laid-open patent publication No. 60-175471

Patent document 2: japanese laid-open patent publication No. 1-298354

Patent document 3: international publication No. 2014/091714 pamphlet

Patent document 4: japanese laid-open patent publication No. 2000-294853

Disclosure of Invention

Problems to be solved by the invention

In the conventional technique, the offset voltage of the hall element may vary.

The invention aims to provide a Hall element, a Hall sensor and a lens module which can restrain the variation of offset voltage.

Means for solving the problems

In order to solve the above problem, a hall element according to an aspect of the present invention includes: a substrate; a magnetic induction part formed on one surface side of the substrate; a first electrode and a second electrode formed on the one surface side and electrically connected to the magnetism sensing portion, the first electrode and the second electrode facing each other in a first direction; and a third electrode and a fourth electrode formed on the one surface side and electrically connected to the magnetism sensing portion, the third electrode and the fourth electrode facing each other in a second direction intersecting the first direction in a plan view, wherein the first electrode, the second electrode, the third electrode, and the fourth electrode extend from a peripheral region of the magnetism sensing portion to a central region of the magnetism sensing portion.

A hall element according to another aspect of the present invention includes: a substrate; a magnetic induction part formed on one surface side of the substrate; a first electrode and a second electrode formed on the one surface side and electrically connected to the magnetism sensing portion, the first electrode and the second electrode facing each other in a first direction; and a third electrode and a fourth electrode which are formed on the one surface side and electrically connected to the magnetism sensing portion, the third electrode and the fourth electrode facing each other in a second direction intersecting the first direction in a plan view, wherein the first electrode, the second electrode, the third electrode, and the fourth electrode are each rectangular in shape in a plan view, and a first corner portion of the first electrode, a second corner portion of the second electrode, a third corner portion of the third electrode, and a fourth corner portion of the fourth electrode are each positioned above the magnetism sensing portion.

A hall element according to another aspect of the present invention includes: a substrate; a magnetic induction part which is formed on one surface side of the substrate and has a rectangular shape in a plan view; a first electrode and a second electrode formed on the one surface side and electrically connected to the magnetism sensing portion, the first electrode and the second electrode facing each other in a first direction; and a third electrode and a fourth electrode formed on the one surface side and electrically connected to the magnetism sensing portion, the third electrode and the fourth electrode facing each other in a second direction intersecting the first direction in a plan view, wherein respective outer peripheries of the first electrode, the second electrode, the third electrode, and the fourth electrode are positioned inward of an outer periphery of the magnetism sensing portion in a plan view.

A hall sensor according to an aspect of the present invention includes: the above hall element; a first terminal portion; a second terminal portion; a third terminal portion; a fourth terminal portion; a first fine metal wire connecting the first electrode and the first terminal portion; a second thin metal wire connecting the second electrode and the second terminal portion; a third fine metal wire connecting the third electrode and the third terminal portion; and a fourth metallic thin wire connecting the fourth electrode and the fourth terminal portion, wherein the first to fourth electrodes each have a region to which the first to fourth metallic thin wires are bonded, and a region in which the first to fourth electrodes are in contact with the magnetism-sensitive portion, and the region in which the first to fourth electrodes are in contact with the magnetism-sensitive portion is located outside a center of a bonding region to which the first to fourth metallic thin wires are bonded, when viewed from a center of the magnetism-sensitive portion.

A hall sensor according to another aspect of the present invention includes: a substrate; a magnetic induction part formed on one surface side of the substrate; an insulating film formed on the magnetic induction portion; an electrode formed on the insulating film; a thin metal wire bonded to one end of the thin metal wire on an upper surface of the electrode; and a terminal portion connected to the other end of the thin metal wire, wherein the magnetic induction portion has a stepped shape formed on the substrate, the insulating film is interposed between the electrode and the magnetic induction portion below a bonding region of an upper surface of the electrode to which the thin metal wire is bonded, and the electrode is connected to the magnetic induction portion outside the bonding region to which the thin metal wire is bonded.

A hall sensor according to another aspect of the present invention includes: the above hall element; a first terminal portion; a second terminal portion; a third terminal portion; a fourth terminal portion; a first fine metal wire connecting the first electrode and the first terminal portion; a second thin metal wire connecting the second electrode and the second terminal portion; a third fine metal wire connecting the third electrode and the third terminal portion; a fourth fine metal wire connecting the fourth electrode and the fourth terminal portion; and a molding member that seals at least a part of the hall element, at least a part of the first to fourth terminal portions, and the first to fourth fine metal wires.

A hall sensor according to another aspect of the present invention includes: a substrate; a magnetic induction part formed on one surface side of the substrate; a first electrode and a second electrode formed on the one surface side and electrically connected to the magnetism sensing portion, the first electrode and the second electrode facing each other in a first direction; a third electrode and a fourth electrode formed on the one surface side and electrically connected to the magnetism sensing portion, the third electrode and the fourth electrode facing each other in a second direction intersecting the first direction in a plan view; an insulating film disposed between the magnetic induction portion and the first to fourth electrodes when viewed in cross section; a plurality of terminal portions; and fine metal wires connecting the first to fourth electrodes and the plurality of terminal portions, wherein each of the first, second, third, and fourth electrodes has a region to which the fine metal wire is bonded and a region in contact with the magnetism sensing portion, the region in contact with the magnetism sensing portion is located outside a center of the region to which the fine metal wire is bonded when viewed from a center of the magnetism sensing portion, the insulating film is interposed between the first to fourth electrodes and the magnetism sensing portion in the region to which the fine metal wire is bonded when viewed in cross section, and the insulating film has an opening in the region in contact with the magnetism sensing portion.

A lens module according to an aspect of the present invention includes: the above hall sensor; a lens holder to which a magnet is mounted; and a driving coil that moves the magnet based on output signals output from the plurality of terminal portions of the hall sensor.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the embodiments of the present invention, variations in offset voltage can be suppressed.

Drawings

Fig. 1 is a diagram showing a configuration example of a hall element 100 according to a first embodiment.

Fig. 2 is a diagram obtained by cutting the hall element 100 shown in fig. 1 along lines a1-a '1 and B1-B' 1.

Fig. 3 is a diagram showing a configuration example of the magnetism sensing part 20 according to the first embodiment.

Fig. 4 is a diagram illustrating the central region 23 in the first embodiment.

Fig. 5 is a diagram showing a configuration example of the first electrode 31 to the fourth electrode 34.

Fig. 6 is a schematic view showing first to fourth wire bonding regions 141 to 144.

Fig. 7 is a diagram showing a configuration example of the hall sensor 700 according to the first embodiment.

Fig. 8 is a diagram illustrating a method of manufacturing the hall element 100 in the order of steps.

Fig. 9 is a view showing a process sequence of the method for manufacturing the hall sensor 700.

Fig. 10 is a view showing a process sequence of the method for manufacturing the hall sensor 700.

Fig. 11 is a diagram showing a configuration example of a hall element 200 according to a second embodiment.

Fig. 12 is a diagram obtained by cutting off hall element 200 shown in fig. 11 along lines F11-F '11 and G11-G' 11.

Fig. 13 is a diagram showing a configuration example of a hall element 300 according to a third embodiment.

Fig. 14 is a diagram obtained by cutting the hall element 300 shown in fig. 13 along lines H13-H '13 and J13-J' 13.

Fig. 15 is a diagram showing a configuration example of the magnetism sensing part 20 according to the third embodiment.

Fig. 16 is a diagram illustrating the central region 23 in the third embodiment.

Fig. 17 is a diagram showing a configuration example of a hall element 400 according to the fourth embodiment.

Fig. 18 is a diagram obtained by cutting the hall element shown in fig. 17 along lines K17-K '17 and M17-M' 17.

Fig. 19 is a diagram showing a configuration example of the magnetism sensing portion 20 according to the fourth embodiment.

Fig. 20 is a diagram illustrating the central region 23 in the fourth embodiment.

FIG. 21 is a graph showing the results of tests conducted in examples 1 to 4 and comparative examples 1 to 4. The graph shows the relationship between the inter-electrode distance and the amount of fluctuation of the offset voltage.

Fig. 22 is a diagram showing a configuration example of a hall element 500 according to a fifth embodiment.

Fig. 23 is a diagram obtained by cutting the hall element 500 shown in fig. 22 along the lines N1-N '1 and O1-O' 1.

Fig. 24 is a diagram showing a configuration example of the magnetism sensing part 20 according to the fifth embodiment.

Fig. 25 is a diagram showing a configuration example of the first electrode 31 to the fourth electrode 34.

Fig. 26 is a schematic view showing first to fourth wire bonding regions 141 to 144.

Fig. 27 is a diagram showing a configuration example of a hall sensor 700 according to a fifth embodiment.

Fig. 28 is a diagram illustrating a method of manufacturing the hall element 500 in order of steps.

Fig. 29 is a view showing a process sequence of the method for manufacturing the hall sensor 700.

Fig. 30 is a view showing a process sequence of the method for manufacturing the hall sensor 700.

Fig. 31 is a diagram showing a configuration example of a hall element 600 according to a sixth embodiment.

Fig. 32 is a diagram illustrating the central region 23 in the seventh embodiment.

Fig. 33 is a diagram illustrating the formation positions of the contact regions and the wire bonding regions in the hall sensor 700 including the hall elements according to the first to seventh embodiments.

Fig. 34 is a diagram illustrating the formation positions of the contact regions and the wire bonding regions in the hall sensor 700 including the hall elements according to the first to seventh embodiments.

Fig. 35 is a diagram showing a schematic configuration of the

lens modules

8a and 8b using the hall sensors 700 according to the first to seventh embodiments.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings. In the drawings described below, the same reference numerals are given to corresponding parts, and the description of overlapping parts will be omitted as appropriate. The embodiments of the present invention are configured to embody the technical idea of the present invention, and the material, shape, structure, arrangement, size, and the like of each part are not specified to the material, shape, structure, arrangement, size, and the like of each part described below. The technical idea of the present invention can be variously modified within the technical scope defined by the claims described in the patent claims.

< first embodiment >

[ Structure ]

(1) Hall element

Fig. 1 is a plan view showing a configuration example of a hall element 100 according to a first embodiment of the present invention. Fig. 2 (a) and 2 (B) are cross-sectional views obtained by cutting the hall element 100 shown in fig. 1 along lines a1-a '1 and B1-B' 1.

As shown in fig. 1, 2 (a) and 2 (b), the hall element 100 includes: a substrate 10; a magnetism sensing portion 20 formed on one surface (e.g., upper surface) 10a side of the substrate 10; first to fourth electrodes 31 to 34, the first to fourth electrodes 31 to 34 being formed on one surface side of the substrate 10 and electrically connected to the magnetism sensing portion 20. The first electrode 31 and the second electrode 32 are input electrodes of the hall element 100, and the third electrode 33 and the fourth electrode 34 are output electrodes of the hall element 100.

(1.1) substrate

The substrate 10 is, for example, a compound semiconductor substrate, and one example thereof is a GaAs substrate. The resistivity of the GaAs substrate was 1.0X 10⁵Omega cm or more. The upper limit of the resistivity of the GaAs substrate 10 is not particularly limited, but is 1.0 × 10 by way of example⁹Omega cm or less. The substrate 10 has a rectangular shape in plan view (hereinafter referred to as "plan view shape"). Examples of the rectangular shape include a square shape, a rectangular shape, a rounded square shape, and a rounded rectangular shape. In addition, the top view is a top view.

(1.2) magnetic sensitive part

The magnetic induction portion 20 is formed on the upper surface 10a of the substrate 10, and has a stepped shape in a cross-sectional view (hereinafter referred to as a "cross-sectional shape"). Alternatively, the magnetic induction portion 20 may be formed inside the substrate 10. In the first embodiment of the present invention, the magnetic induction portion 20 has a rectangular shape in plan view. In the embodiments of the present invention, the position where the magnetic induction portion 20 is formed is not limited to the upper surface 10a of the substrate 10. The magnetism sensing portion (active layer) 20 may be formed partially or entirely inside the upper surface 10a side of the substrate 10. In addition, from the viewpoint of temperature characteristics, the magnetism sensing portion 20 is preferably formed of GaAs. However, the present embodiment is not limited to the structure in which the magnetic induction portion 20 is formed of GaAs, and for example, a compound semiconductor such as InSb or InAs may be used.

The magnetic induction portion 20 is a layer having a lower resistance than the substrate 10. The magnetic sensitive part 20 is formed by, for example, a method of implanting impurities such as Si, Sn, S, Se, Te, Ge, or C into the substrate 10 and activating the impurities by heating, or a method of growing a compound semiconductor containing the impurities on the substrate 10 by an epitaxial growth method such as an MOCVD (Metal Organic Chemical Vapor Deposition) method or an MBE (Molecular Beam Epitaxy) method.

For example, the magnetic induction portion 20 includes a conductive layer 21 and a surface layer 22 formed on the conductive layer 21. The conductive layer 21 includes n-type GaAs formed on the substrate 10. The film thickness of the conductive layer 21 is not particularly limited, but is preferably 50nm or more and 2000nm or less, and more preferably 100nm or more and 1000nm or less, from the viewpoint of ease of production.

As the n-type impurity (i.e., donor-type impurity) of the n-type GaAs, a known n-type impurity, for example, Si, Ge, Se, or the like can be used. The concentration of the n-type impurity (effective carrier concentration) is not particularly limited, and the effective carrier concentration is preferably 1.0 × 10 from the viewpoint of the output and temperature characteristics of the hall element¹⁴[cm^-3]Above and 1.0X 10¹⁹[cm^-3]Hereinafter, more preferably 1.0 × 10¹⁵[cm^-3]Above and 1.0X 10¹⁸[cm^-3]Hereinafter, more preferably 1.0 × 10¹⁵[cm^-3]Above and 5.0X 10¹⁷[cm^-3]The following. If the effective carrier concentration is within the above range, the temperature dependence of the output is easily suppressed and the absolute value of the output is easily obtained, which is preferable.

As a method of forming the conductive layer 21, there is a method of forming an n-type GaAs layer near the surface of the substrate 10 or inside the substrate 10 by ion-implanting impurities into the substrate 10. Another method for forming the conductive layer 21 is to dope impurity ions on the substrate 10 by MBE (molecular beam epitaxy) or MOCVD (metal organic chemical vapor deposition) and epitaxially grow a GaAs thin film.

The surface layer 22 is formed on the conductive layer 21, and is a GaAs layer having lower conductivity than the conductive layer 21, or a layer containing a high-resistance crystal such as AlGaAs or AlAs. The film thickness of the surface layer 22 is preferably 150nm or more, preferably 200nm or more, in order to realize a hall element in which variation in sheet resistance is suppressed, and is otherwise 800nm or less, more preferably 600nm or less, from the viewpoint of ease of manufacturing. Furthermore, the surface layer may be absent.

The method for forming the surface layer 22 is not particularly limited, and can be formed by, for example, an ion implantation method or epitaxial growth using an MBE method or an MOCVD method. As a method for obtaining GaAs having lower conductivity than the conductive layer 21 as in the surface layer 22, there can be mentioned a method of making the concentration of impurities lower than the conductive layer 21, a method of intentionally not doping impurities, and the like. In order to directly connect the conductive layer 21 to the first to fourth electrodes 31 to 34 in an ohmic manner, a portion of the surface layer 22 may be etched to be thinned or removed.

Fig. 3 is a plan view showing a configuration example of the magnetism sensing portion 20. As shown in fig. 3, in a plan view, the center position 25 of the rectangular magnetic induction portion 20 substantially coincides with the center position of the rectangular substrate 10. In addition, in a plan view, the first side 26 to the fourth side 29 of the outer periphery of the magnetism sensing part 20 are parallel to two sides of the first side 11 to the fourth side 14 of the outer periphery of the substrate 10, respectively. That is, in a plan view, the first side 26 to the fourth side 29 of the outer periphery of the magnetism sensing part 20 are parallel to or perpendicular to the first side 11 to the fourth side 14 of the outer periphery of the substrate 10. More specifically, the first and

third sides

11 and 13 of the outer periphery of the magnetism sensing part 20 are parallel to the first and

third sides

26 and 28 of the outer periphery of the substrate 10 and perpendicular to the second and

fourth sides

27 and 29 of the outer periphery of the substrate 10. The second and

fourth sides

12 and 14 of the outer periphery of the magnetic induction part 20 are parallel to the second and

fourth sides

27 and 29 of the outer periphery of the substrate 10 and perpendicular to the first and

third sides

26 and 28 of the outer periphery of the substrate 10.

The magnetic sensing portion 20 has a central region 23 including a central position 25 of the magnetic sensing portion 20 in a plan view, and a peripheral region 24 located in the periphery of the central region 23. The central region 23 has a shape of, for example, a perfect circle in a plan view. The magnetic induction portion 20 has a square shape in plan view, for example.

Fig. 4 is a diagram illustrating the central region 23 in the first embodiment. As shown in fig. 4, in the first embodiment, the central region 23 is set to be, for example, an inner region of a circle shown by a broken line. To describe in detail, as shown in fig. 4, an auxiliary circle 30 having a radius equal to the minimum distance from the center of gravity to the contact region is defined as a circle having the same center as the geometric center of gravity (illustrated by a + mark) of the magnetism sensing part 20 in a plan view. The central region 23 is defined as an inner region of a circle having a diameter of 1/2 with respect to the auxiliary circle 30 and having the center of gravity as a center. The geometric center of gravity of the magnetic sensitive portion 20 can be determined in a figure surrounded by the boundary between the magnetic sensitive portion 20 and the substrate 10 in a plan view. The contact regions are portions where the first to fourth electrodes 31 to 34 are connected to the magnetism sensing portion 20, respectively.

The central region (for example, a circular inner region shown by a dotted line) 23 is a main region that contributes to the hall effect in the magnetic induction portion 20. The outer side of the central region 23 is referred to as a peripheral region 24.

The central region 23 may have a rectangular shape in plan view.

(1.3) electrodes

Fig. 5 is a plan view showing a configuration example of the first electrode 31 to the fourth electrode 34. As shown in fig. 5, the first electrode 31 and the second electrode 32 face each other in the first direction. In addition, the third electrode 33 and the fourth electrode 34 face each other in a second direction intersecting (e.g., orthogonal to) the first direction in a plan view. The first to fourth electrodes 31 to 34 extend from the peripheral region 24 to the central region 23 of the magneto-sensitive portion 20.

That is, the first electrode 31 has a main portion 31a and an extension portion 31b extending from the main portion 31a toward the central region 23 of the magnetism sensing portion 20. The second electrode 32 has a main portion 32a and an extension portion 32b extending from the main portion 32a toward the central region 23 of the magnetism sensing portion 20. The third electrode 33 has a main portion 33a and an extension portion 33b extending from the main portion 33a toward the central region 23 of the magnetism sensing portion 20. The fourth electrode 34 has a main portion 34a and an extension portion 34b extending from the main portion 34a toward the central region 23 of the magnetism sensing portion 20.

As shown in fig. 5, when the separation distance between the first electrode 31 and the second electrode 32 in the first direction (i.e., the separation distance between the extending

portions

31b, 32 b) is D1 and the separation distance between the third electrode 33 and the fourth electrode 34 in the second direction (i.e., the separation distance between the extending

portions

33b, 33 c) is D2, D1 and D2 are 1 μm or more and 40 μm or less, respectively.

The shapes and the arrangements of the first to fourth electrodes 31 to 34 will be described more specifically by way of example.

The first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 each have a rectangular shape in plan view. The first corner 31c of the first electrode 31, the second corner 32c of the second electrode 32, the third corner 33c of the third electrode 33, and the fourth corner 34c of the fourth electrode 34 are located above the magnetism sensing portion 20, respectively.

Here, the first corner 31c is a portion included in the extension 31b of the first electrode 31. The second corner portion 32c is a portion included in the extension portion 32b of the second electrode 32. The third corner 33c is a portion included in the extension 33b of the third electrode 33. The fourth corner 34c is a portion included in the extension 34b of the fourth electrode 34. As shown in fig. 5, the first corner portion 31c, the second corner portion 32c, the third corner portion 33c, and the fourth corner portion 34c are disposed adjacent to each other. The first corner 31c is adjacent to the third corner 33c and the fourth corner 34c, the second corner 32c is adjacent to the third corner 33c and the fourth corner 34c, the first corner 31c and the second corner 32c face each other in the first direction, and the third corner 33c and the fourth corner 34c face each other in the second direction.

The center position of the region surrounded by the first corner portion 31c, the second corner portion 32c, the third corner portion 33c, and the fourth corner portion 34c overlaps the center position of the magnetism sensing portion 20 in a plan view. In addition, in a plan view, the outer peripheries of the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 are located inside the region surrounded by the outer periphery of the magnetism sensing portion 20 (i.e., the region surrounded by the first side 26 to the fourth side 29).

As shown in fig. 1, the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 are disposed at four corners of the rectangle of the substrate 10. Further, the respective sides of the outer peripheries of the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 are parallel to two sides of the outer periphery of the substrate 10. That is, in a plan view, the respective sides of the outer peripheries of the first to fourth electrodes 34 are parallel to or perpendicular to the first to fourth sides 11 to 14 of the outer periphery of the substrate 10.

As shown in fig. 2, each of the first to fourth electrodes 31 to 34 includes a first metal film 131 electrically connected to the magnetism sensing portion 20 and a second metal film 132 formed on the first metal film 131. That is, the first metal film 131 is a contact region with the magnetic induction portion 20. Further, an insulating film 40 is formed between the magnetic sensitive portion 20 and the second metal film 132. The insulating film 40 is, for example, a silicon nitride film (Si)₃N₄Film), silicon oxide film (SiO)₂Film), inorganic film (Al)₂O₃) And a polyimide film, a multilayer film in which a plurality of these films are laminated. The insulating film 40 may be formed on the first metal film 131 as shown in fig. 2, may not be formed on the first metal film 131, or may be formed so as to partially enter under the first metal film 131.

In the hall element of the present embodiment, the minimum distance between adjacent electrodes among the plurality of electrodes is preferably 2 μm or more and 11 μm or less in a plan view. The minimum distance is more preferably 4 μm or more and 11 μm or less, still more preferably 4 μm or more and less than 10 μm, and still more preferably 5 μm or more and 9 μm or less. The minimum distance between adjacent electrodes means the smallest distance among all the inter-electrode distances.

(1.4) region for connecting fine metallic wires (wire bonding region)

Fig. 6 (a) to 6 (C) are schematic views showing the wire bonding region of the hall element 100, fig. 6 (a) is a plan view, fig. 6 (b) is a sectional view of fig. 6 (a) taken along line C5-C '5, and fig. 6 (C) is a sectional view of fig. 6 (a) taken along line D5-D' 5.

As shown in fig. 6 (a) to 6 (c), the first electrode 31 has a first wire bonding region 141 on its upper surface side to which the thin metal wire is bonded. The first metal film 131 constituting the first electrode 31 is a contact region where the first electrode 31 is in contact with the magnetism sensing part 20.

In addition, the second electrode 32 has a second wire bonding region 142 on the upper surface side thereof to which the thin metal wire is bonded. The first metal film 131 constituting the second electrode 32 is a contact region where the second electrode 32 is in contact with the magnetism sensing part 20.

In addition, the third electrode 33 has a third wire bonding region 143 on its upper surface side to which the thin metal wire is bonded. The first metal film 131 constituting the third electrode 33 is a contact region where the third electrode 33 is in contact with the magnetism sensing part 20.

In addition, the fourth electrode 34 has a fourth wire bonding region 144 on the upper surface side thereof to which the thin metal wire is bonded. The first metal film 131 constituting the fourth electrode 34 is a contact region where the fourth electrode 34 is in contact with the magnetism sensing part 20.

That is, the contact regions of the first electrode 31 to the fourth electrode 34 are located outside the center positions of the first wire bonding region 141 to the fourth wire bonding region 144, respectively, when viewed from the center position 25 of the magnetism sensing portion 20.

As described above, the first electrode 31 and the second electrode 32 are input electrodes of the hall element 100, and thus a signal input path 146 of the hall element 100 is between a contact area of the first electrode 31 and a contact area of the second electrode 32. In addition, since the third electrode 33 and the fourth electrode 34 are output electrodes of the hall element 100, a signal output path 145 of the hall element 100 is formed between a contact area of the third electrode 33 and a contact area of the fourth electrode 34.

(2) Hall sensor

Fig. 7 (a) to 7 (d) are cross-sectional views, plan views, bottom views, and external views showing structural examples of the hall sensor 700 according to the first embodiment of the present invention. Fig. 7 (a) shows a cross section of fig. 7 (b) cut along the broken line E7-E' 7. In fig. 7 (b), the molded member is omitted to avoid complication of the drawing.

As shown in fig. 7 (a) to 7 (d), the hall sensor 700 includes the hall element 100, the lead terminal 520, the first to fourth fine metal wires (conductive connecting members) 531 to 534, the protective layer 540, the mold member 550, and the case plating layer 560. The lead terminal 520 includes first to fourth terminal portions 521 to 524.

The hall sensor 700 has, for example, an island-less structure, and has a plurality of terminal portions 521 to 524 for obtaining electrical connection with the outside. As shown in fig. 7 (b), the first to fourth terminal portions 521 to 524 are disposed around the hall element 100.

For example, the first terminal portion 521 and the second terminal portion 522 are disposed so as to face each other with the hall element 100 interposed therebetween, and the third terminal portion 523 and the fourth terminal portion 524 are disposed so as to face each other with the hall element 100 interposed therebetween. A straight line (virtual line) connecting the first terminal portion 521 and the second terminal portion 522 intersects a straight line (virtual line) connecting the third terminal portion 523 and the fourth terminal portion 524 in a plan view. The lead terminals 520 (the first to fourth terminal portions 521 to 524) include metal such as copper (Cu), for example.

The first to fourth fine metal wires 531 to 534 are wires that electrically connect the first to fourth electrodes 31 to 34 and the first to fourth terminal portions 521 to 524 of the hall element 100, respectively, and include, for example, gold (Au). As shown in fig. 7 (b), the first fine metal wire 531 connects the first terminal portion 521 and the first electrode 31. The second fine metallic wire 532 connects the second terminal portion 522 and the second electrode 32. The third fine metal wire 533 connects the third terminal portion 523 to the third electrode 33. The fourth fine metal wire 534 connects the fourth terminal portion 524 to the fourth electrode 34.

One end of the first fine metal wire 531 is connected to the first electrode 31, and the other end of the first fine metal wire 531 is connected to the first terminal portion 521. One end of the second fine metal wire 532 is connected to the second electrode 32, and the other end of the second fine metal wire 532 is connected to the second terminal portion 522. One end of the third fine metal wire 533 is connected to the third electrode 33, and the other end of the third fine metal wire 533 is connected to the third terminal portion 523. One end of the fourth fine metal wire 534 is connected to the fourth electrode 34, and the other end of the fourth fine metal wire 534 is connected to the fourth terminal portion 524.

The first to fourth wire bonding regions 141 to 144 correspond to partial regions of the upper surfaces of the first to fourth electrodes 31 to 34. The insulating film 40 is interposed between the first to fourth electrodes and the magnetism sensing portion 20 below the bonding regions where the first to fourth fine metal wires 531 to 534 (details will be described later) on the upper surfaces of the first to fourth electrodes 31 to 34 are bonded. Here, the "bonding region" is a region where the first to fourth fine metal wires 531 to 534 actually contact the upper surfaces of the first to fourth electrodes 31 to 34, and is not the spherical diameter of the first to fourth fine metal wires 531 to 534. Therefore, bonding regions where the first to fourth fine metal wires 531 to 534 are bonded to the upper surfaces of the first to fourth electrodes 31 to 34 are present in the first to fourth wire bonding regions 141 to 144. As described above, the contact regions of the first electrode 31 to the fourth electrode 34 are located outside the center positions of the first wire bonding region 141 to the fourth wire bonding region 144, respectively, when viewed from the center position 25 of the magnetism sensing portion 20. Therefore, the first to fourth electrodes 31 to 34 are connected to the magnetism sensing portion 20 outside the bonding regions where the first to fourth fine metal wires 531 to 534 are bonded to the upper surfaces of the first to fourth electrodes 31 to 34.

As described above, the first metal film 131 is a contact region with the magnetic induction portion 20. An opening 401 of the insulating film 40 is provided in the first metal film 131 (see fig. 2). Therefore, the opening 401 of the insulating film 40 is disposed outside the bonding region where the first to fourth fine metal wires 531 to 534 are bonded to the upper surfaces of the first to fourth electrodes 31 to 34 when viewed from the center position 25 of the magnetism sensing portion 20. That is, the insulating film 40 has an opening 401 located outside the bonding region in a plan view. The first to fourth electrodes 31 to 34 are in contact with the magnetism sensing portion 20 at the opening 401. Therefore, the regions of the first to fourth electrodes 31 to 34 in contact with the magnetism sensing portion 20 are disposed outside the region where the first to fourth fine metal wires 531 to 534 are bonded.

The protective layer 540 covers the surface side of the substrate 10 opposite to the surface on which the first to fourth electrodes 31 to 34 are provided.The protective layer 540 is not particularly limited as long as it can protect the substrate 10, and may include at least one of a conductor, an insulator, and a semiconductor. That is, the protective layer 540 may be a film including any one of a conductor, an insulator, and a semiconductor, or may be a film including two or more of these. As the conductor, for example, a conductive resin such as silver paste can be considered. As the insulator, for example, a thermosetting resin containing an epoxy group and Silica (SiO) as a filler can be considered₂) Insulating paste of (1), silicon nitride, silicon dioxide, etc. As the semiconductor, for example, bonding of an Si substrate, a Ge substrate, or the like can be considered. However, the protective layer 540 is preferably an insulator from the viewpoint of preventing leakage current. The protective layer 540 may have a laminated structure.

The molding member 550 molds the hall element 100, the first to fourth terminal portions 521 to 524, and the first to fourth thin metal wires 531 to 534. In other words, the mold member 550 covers and protects (i.e., resin-seals) the hall element 100, at least the surface side (i.e., the surface on the side connected to the thin metal wires) of the first to fourth terminal portions 521 to 524, and the first to fourth thin metal wires 531 to 534. The molding member 550 is made of, for example, thermosetting resin of epoxy system, and can resist high heat during reflow soldering.

As shown in fig. 7 a and 7 c, at least a part of the first surfaces (e.g., the back surfaces) of the first to fourth terminal portions 521 to 524 and at least a part of the first surface (e.g., the back surface) of the GaAs substrate 10 are exposed from the same surface (e.g., the back surface) of the mold member 550 on the bottom surface side of the hall sensor 700 (i.e., the side mounted on the wiring substrate magnetism sensing portion 20). Here, the first surface of the first to fourth terminal portions 521 to 524 is a surface opposite to the surface connected to the first to fourth fine metal wires 531 to 534 among the plurality of surfaces of the first to fourth terminal portions 521 to 524. The first surface of the GaAs substrate 10 is a surface opposite to the surface on which the first to fourth electrodes 31 to 34 are provided, among the plurality of surfaces of the GaAs substrate 10.

The case plating 560 is formed on the back surface of the terminal portions 521 to 524 exposed from the mold member 550. The case plating 560 contains, for example, tin (Sn).

[ act ]

When the hall sensor 700 described above is used to detect magnetism (magnetic field), for example, the first terminal portion 521 is connected to a power supply potential (+), the second terminal portion 522 is connected to a ground potential (GND), and current is caused to flow from the first terminal portion 521 to the second terminal portion 522. Then, the potential difference V1-V2 (hall output voltage VH) between the third terminal portion 523 and the fourth terminal portion 524 is measured. The magnitude of the magnetic field is detected from the magnitude of the hall output voltage VH, and the direction of the magnetic field is detected from the positive and negative of the hall output voltage VH.

That is, the first terminal 521 is a power supply terminal for supplying a predetermined voltage to the hall element 100. The second terminal portion 522 is a ground terminal portion for supplying a ground potential to the hall element 100. The third terminal portion 523 and the fourth terminal portion 524 are signal extracting terminal portions for extracting the hall electromotive force signal of the hall element 100.

[ production method ]

(1) Method for manufacturing Hall element

Fig. 8 (a) to 8 (e) are sectional views illustrating a method for manufacturing the hall element 100 in the order of steps. As shown in fig. 8 (a), first, the substrate 10 is prepared. The substrate 10 is, for example, a GaAs substrate 10. Next, a donor-type impurity is ion-implanted into a position at a predetermined depth from the surface of the substrate 10. Examples of the donor-type impurity include Si, Sn, S, Se, Te, Ge, and C. Next, the substrate 10 is heated to activate the impurities. As a result, as shown in fig. 8 (b), a conductive layer 21 having a lower electrical resistance than that of the substrate 10 is formed in the substrate 10, and a surface layer 22 is formed on the conductive layer 21. The surface layer 22 has a lower impurity concentration than the conductive layer 21, and is therefore a layer having a higher resistance (i.e., a layer having a lower conductivity) than the conductive layer 21.

The step of activating the impurities may be performed after the step of patterning the substrate 10 shown in fig. 8 (c). Further, the heating step may be performed in combination with other heating steps after the step shown in fig. 8 (c). The formation of the conductive layer 21 is not limited to ion implantation. For example, GaAs containing a high concentration of impurities may be epitaxially grown on the substrate 10 by MOCVD to form the conductive layer 21. In this case, after the conductive layer 21 is formed, the surface layer 22 having a higher resistance than the conductive layer 21 can be formed on the conductive layer 21 by epitaxially growing GaAs containing a low concentration of impurities (or containing no impurities).

Next, the substrate 10 is patterned by using a photolithography technique and an etching technique, and as shown in fig. 8 (c), the magnetic induction portion 20 having a step-like shape in cross section is formed.

Next, as shown in fig. 8 (d), a first metal film 131 is partially formed on the substrate 10 on which the magnetic induction portion 20 is formed. Here, as the first metal film 131, for example, an AuGe film, a Ni film, and an Au film are laminated in this order. The first metal film 131 is formed by, for example, peeling or mask evaporation. The peeling was as follows: the metal film is evaporated on the substrate on which the resist pattern is formed, and then the resist pattern is removed, whereby the metal film remains only on the region of the substrate not covered with the resist pattern. Mask evaporation is the following method: the metal film is deposited on the substrate by a plate having a partial through-hole, and thereby the metal film is deposited only in a region directly below the through-hole of the substrate. After the first metal film 131 is formed, the substrate 10 is heated to alloy the interface between the substrate 10 and the first metal film 131.

Next, as shown in fig. 8 (e), the insulating film 40 is formed in a portion exposed from the first metal film 131 of the substrate 10. The insulating film 40 is, for example, a silicon nitride film. The insulating film 40 is formed, for example, by the following method: an insulating film is formed on the entire upper surface of the substrate 10 by a CVD (Chemical Vapor Deposition) method, and then the insulating film formed on the entire upper surface is patterned using a photolithography technique and an etching technique. Note that, after an insulating film is formed over the entire upper surface of the substrate 10 and patterned to form the insulating film 40, the first metal film 131 may be formed.

Next, as shown in fig. 8 (e), a second metal film 132 is partially formed on the substrate 10 on which the insulating film 40 is formed. Here, as the second metal film 132, for example, a Ti film and an Au film are laminated in this order. The second metal film 132 is formed by, for example, lift-off or mask evaporation.

Then, a protective film (not shown) or the like is formed on the substrate 10. Then, the substrate 10 is cut, and the substrate 10 is singulated for each of the plurality of hall elements 100. Through the above steps, the hall element 100 shown in fig. 1 and the like is completed.

(2) Manufacturing method of Hall sensor

Fig. 9 (a) to 9 (e) and fig. 10 (a) to 10 (d) are a plan view and a cross-sectional view showing a process sequence of the method for manufacturing the hall sensor 700. Note that, in fig. 9 (a) to 9 (e), the blade width of the dicing (i.e., the notch width) is not shown.

As shown in fig. 9 (a), a lead frame 620 is first prepared. The lead frame 620 is a substrate in which a plurality of lead terminals 520 shown in fig. 7 (b) are connected in the vertical direction and the horizontal direction in a plan view.

Next, as shown in fig. 9 (b), one surface of a heat-resistant film 580 as a base material is attached to the back surface of the lead frame 620. An insulating adhesive layer is applied to one surface of the heat-resistant film 580, for example. The adhesive layer is made of, for example, silicone resin as a base material. The lead frame 620 can be easily attached to the heat-resistant film 580 by the adhesive layer. By attaching the heat-resistant film 580 to the back surface side of the lead frame 620, the through region penetrating the lead frame 620 is sealed from the back surface side by the heat-resistant film 580.

Next, as shown in fig. 9 (c), the hall element 100 having the protective layer 540 is placed (i.e., die-bonded) on the surface of the heat-resistant film 580 having the adhesive layer in the region surrounded by the first to fourth terminal portions 521 to 524. Here, the first surface of the substrate 10 is opposed to the surface of the heat-resistant film 580 having the adhesive layer, and die bonding is performed.

Next, as shown in fig. 9 (d), one ends of the first to fourth fine metal wires 531 to 534 are connected to the first to fourth terminal portions 521 to 524, respectively, and the other ends of the first to fourth fine metal wires 531 to 534 are connected to the first to fourth electrodes 31 to 34 of the hall element 100, respectively (that is, wire-bonded).

The wire bonding may be a forward bonding in which a thin metal wire is extended from each electrode of the hall element 100 to each terminal portion of the lead terminal 520, or conversely a reverse bonding in which a thin metal wire is extended from each terminal portion of the lead terminal 520 to each electrode of the hall element 100. The reverse bonding can reduce the loop height after bonding of the thin metal wire as compared with the forward bonding, and therefore can contribute to thinning of the hall element.

Then, as shown in fig. 9 (e), a molding member 550 is formed (i.e., resin molding is performed). The resin molding is performed, for example, using a transfer molding technique.

For example, as shown in fig. 10 (a), a mold 590 including a lower mold 591 and an upper mold 592 is prepared, and a lead frame 620 after wire bonding is disposed in a cavity of the mold 590. Next, the molding member 550 heated and melted is injected and filled into one side of the heat-resistant film 580 in the cavity, which has the surface having the adhesive layer (i.e., the surface to be adhered to the lead frame 620). Thus, the Hall element 100, the lead frame 620 and the thin metal wires 531 to 534 are molded. That is, the hall element 100, at least the surface side of the lead frame 620, and the fine metal wires 531 to 534 are covered and protected by the mold member 550. When the molding member 550 is further heated to be cured, the molding member 550 is removed from the molding die.

Next, as shown in fig. 10 (b), the heat-resistant film 580 is peeled off from the molding member 550. Thereby, the substrate 10 of the hall element 100 is exposed from the molding member 550. Then, as shown in fig. 10 c, a surface of the lead frame 620 exposed from the mold member 550 (at least a back surface of each of the terminal portions 521 to 524 exposed from the mold member 550) is coated with a plating film to form a plated case layer 560.

Next, as shown in fig. 10 (d), a dicing tape 593 is stuck on the upper surface of the molding member 550 (i.e., the surface of the hall sensor 700 opposite to the surface having the case plating 560). Then, for example, along a virtual two-dot chain line shown in fig. 9 (e), the blade is moved relatively to the lead frame 620 to cut (i.e., cut) the molding member 550 and the lead frame 620. That is, the molding member 550 and the lead frame 620 are cut to be singulated for each of the plurality of hall elements 100. Through the above steps, the hall sensor 700 shown in fig. 7 is completed.

[ Effect of the first embodiment ]

(1) In a thinned hall sensor, since a mold member on a hall element is thin, electromagnetic waves including light incident on a magnetism sensing portion of the hall element cause local variations in electrical conductivity of the magnetism sensing portion due to a photoelectric effect. In addition, the hall element generates an offset voltage Vu due to the fluctuation.

In contrast, according to the first embodiment, the first to fourth electrodes 31 to 34 extend from the peripheral region 24 to the central region 23 of the magnetism sensing portion 20 in a plan view, and a part of the central region 23 is covered with the first to fourth electrodes 31 to 34.

For example, the first to fourth electrodes 31 to 34 are formed to extend from four corners of the rectangular substrate 10 toward the central region 23 of the magnetism sensing portion 20. In the central region 23, the extending portions 31b to 34b of the first electrode 31 to the fourth electrode 34 are disposed close to each other, and the gap between the adjacent electrodes is narrowed. Thereby, a part of the central region 23 of the magnetism sensing part 20 is covered with the first to fourth electrodes 31 to 34.

Here, the metal as the electrode member excellently absorbs the electromagnetic wave containing light. Therefore, the first to fourth electrodes 31 to 34 can shield electromagnetic waves incident on the magnetism sensing portion 20 of the hall element 100, and can suppress local conductivity variation of the magnetism sensing portion 20. This has the effect of suppressing the variation of the offset voltage Vu.

In particular, if the ratio of the total area of the first to fourth electrodes 31 to 34 in the central region to the area of the central region of the magnetism sensing portion 20 in plan view is 10% or more and less than 100%, the effect of suppressing the variation in the offset voltage Vu is high. The ratio is preferably 20% to 99%, more preferably 40% to 95%.

In addition, the ratio of the area of the effective region under the first to fourth electrodes 31 to 34 to the entire area of the effective region of the magnetism sensing portion 20 is preferably 40% to 99% in a plan view. Here, the "area of the effective region" refers to the area obtained by dividing the total area of the first to fourth contact regions where the magnetic sensitive portion 20 is in contact with the first to fourth electrodes 31 to 34, out of the area of the magnetic sensitive portion 20 in a plan view.

(2) In addition, local stress is applied to the magnetism sensing portion due to a filler or the like in a mold member constituting the package. When the stress is received, the electrical conductivity locally fluctuates due to the piezoresistive effect of the semiconductor which is the material of the magnetosensitive portion. As a result, the hall element generates an offset voltage Vu.

In contrast, according to the first embodiment, since the metal serving as the electrode member is plastically deformed flexibly according to the stress, the local stress from the mold member 550 can be relaxed, and the local variation in the electrical conductivity of the magnetism sensing portion 20 can be suppressed. This has the effect of suppressing the fluctuation of the offset voltage Vu of the hall element.

(3) The heat generated in the magnetism sensing unit 20 is discharged from the magnetism sensing unit 20 to the outside of the package through the first to fourth electrodes 31 to 34, the first to fourth fine metal wires 531 to 534, and the first to fourth terminal units 521 to 524. The magnetism sensing part 20 is covered with the first to fourth electrodes 31 to 34 made of metal having high conductivity, and thereby a heat extraction path from the magnetism sensing part 20 through the insulating film 40, the first to fourth electrodes 31 to 34, and the first to fourth thin metal wires 531 to 534 is newly increased. This has the effect of improving the heat dissipation characteristics of the hall element.

(4) Further, when viewed from the center position of the magnetism sensing part 20, the contact regions of the first to fourth electrodes 31 to 34 (i.e., the positions where the first metal films 131 are formed) are located outside the centers of the first to fourth wire bonding regions 141 to 144, respectively. Accordingly, the distances between the signal output path 145 and the signal input path 146 can be made longer without increasing the chip area of the hall element as compared with the case where the contact region is present directly below the wire bonding region, and therefore, the improvement in the magnetic detection accuracy of the hall element can be contributed.

In particular, in the hall element 100, the magnetic induction portion 20 has a rectangular shape in plan view, and the contact regions of the first electrode 31 to the fourth electrode 34 are disposed at the corners of the magnetic induction portion 20. This makes it possible to maximize the respective signal output path 145 and signal input path 146 in a limited chip area, and to greatly contribute to the improvement of the magnetic detection accuracy.

(5) Unlike electrostatic discharge (human body mode ESD) caused by a human body, electrostatic discharge (machine-Static discharge) caused by a machine in an assembly process generates a rapid discharge in an extremely short time. Specifically, at the time of electrostatic discharge caused by a human body, the accumulated electric charge is applied to the hall element via the human body (high resistance). Therefore, equivalent to an RC circuit (Resistance-Capacitance Circuits), it takes time associated with a large time constant for discharge transfer. On the other hand, when static electricity is discharged by a machine, the static electricity is applied to the hall element through the machine (low resistance or wiring), and thus the discharge is instantaneously transmitted to the hall element. Thus, electrostatic discharge caused by the human body is completely different from electrostatic discharge caused by machinery.

When the discharge current caused by the machine flows through the magnetism sensing portion of the hall element, the hall element is rapidly heated and the characteristics of the hall element change.

In embodiment 1, if the minimum distance between adjacent electrodes among the plurality of electrodes is 11 μm or less in a plan view, a path through which a discharge current flows directly from the electrode to the adjacent electrode without passing through the magnetism sensing portion can be obtained. This reduces the influence of the discharge current on the magnetic induction portion, and can sufficiently cope with ESD. As described above, as a countermeasure against the machine mode ESD, the present inventors have found that a countermeasure against the mechanical ESD can be taken by forming a path for a discharge current to flow from an electrode by reducing the inter-electrode distance with a challenge.

In embodiment 1, if the minimum distance between adjacent electrodes among the plurality of electrodes is 2 μm or more in a plan view, it is possible to suppress a leakage current from flowing from the electrode to the adjacent electrode.

As described above, the formation of the leakage current path can be prevented, the countermeasure against ESD can be improved, and the offset voltage variation of the hall element can be suppressed satisfactorily.

< second embodiment >

In the first embodiment described above, the case where the outer peripheries of the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 are located inside the region surrounded by the outer periphery of the magnetism sensing portion 20 in a plan view is described. However, the present invention is not limited thereto.

Fig. 11 is a plan view showing a configuration example of a hall element 200 according to a second embodiment of the present invention. Fig. 12 (a) and 12 (b) are cross-sectional views obtained by cutting the hall element 200 shown in fig. 11 along lines F11-F '11 and G11-G' 11. As shown in fig. 11, 12 (a), and 12 (b), in the hall element 200 according to the second embodiment, at least a part of the outer periphery of each of the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 may be located outside the region surrounded by the outer periphery of the magnetism sensing portion 20 in a plan view. In the second embodiment, as in the first embodiment, the center area may be defined by using the auxiliary circle.

Even with such a configuration, in a plan view, the first to fourth electrodes 31 to 34 extend from the peripheral region 24 to the central region 23 of the magnetism sensing portion 20, and a part of the central region 23 is covered with the first to fourth electrodes 31 to 34. Therefore, the second embodiment achieves the same effects as the effects (1) to (5) of the first embodiment.

< third embodiment >

In the first and second embodiments described above, the case where the magnetic induction portion 20 has a rectangular shape in a plan view has been described. However, the present invention is not limited thereto.

Fig. 13 is a plan view showing a configuration example of a hall element 300 according to a third embodiment of the present invention. Fig. 14 (a) and 14 (b) are cross-sectional views obtained by cutting the hall element 300 shown in fig. 13 along lines H13-H '13 and J13-J' 13. Fig. 15 is a plan view showing a configuration example of the magnetism sensing part 20 according to the third embodiment.

As shown in fig. 13 to 15, the magnetic induction portion 20 may include a main magnetic induction portion 120 having a rectangular shape in plan view, and first to fourth extending portions 121 to 124 extending outward from the four corners of the main magnetic induction portion 120. In a plan view, the first extension portion 121 and the second extension portion 122 are respectively located on an extension line of the first diagonal line 126 of the main magnetic induction portion 120. In addition, the third extension portion 123 and the fourth extension portion 124 are respectively located on an extension line of the second diagonal line 127 of the main magnetic induction portion 120.

As shown in fig. 13, the first extension 121 is electrically connected to the first electrode 31. The second extension portion 122 is electrically connected to the second electrode 32. The third extension 123 is electrically connected to the third electrode 33. The fourth extension 124 is electrically connected to the fourth electrode 34. In the third embodiment, the center area may be defined by using the auxiliary circle, as in the first embodiment.

Fig. 16 is a diagram illustrating the central region 23 in the third embodiment. As shown in fig. 16, also in the third embodiment, similarly to the first embodiment, an inner region of a circle having a diameter 1/2 compared to the auxiliary circle 30 and having a geometric center of gravity (illustrated by a + mark) of the magnetism sensing part 20 as a center is set as the central region 23.

Even with such a configuration, in a plan view, the first to fourth electrodes 31 to 34 extend from the peripheral region 24 to the central region 23 of the magnetism sensing portion 20, and a part of the central region 23 is covered with the first to fourth electrodes 31 to 34. Therefore, the third embodiment achieves the same effects as the effects (1) to (5) of the first embodiment.

< fourth embodiment >

In the first and second embodiments described above, the case where the magnetic induction portion 20 has a rectangular shape in a plan view has been described. In the third embodiment, the case where the main magnetic induction portion 120 has a rectangular shape is described. However, the present invention is not limited thereto.

Fig. 17 is a plan view showing a configuration example of a hall element 400 according to a fourth embodiment of the present invention. Fig. 18 (a) and 18 (b) are cross-sectional views obtained by cutting the hall element shown in fig. 17 along the lines K17-K '1 and M17-M' 17. Fig. 19 is a plan view showing a configuration example of the magnetism sensing part 20 according to the fourth embodiment.

As shown in fig. 17 to 19, the magnetic induction portion 20 has a cross shape in plan view, and includes a central portion 220 and first to fourth peripheral portions 221 to 224 located around the central portion 220.

The first peripheral portion 221 is located on one side in the first direction in the periphery of the central portion 220 in a plan view. The second peripheral portion 222 is located on the other side in the first direction in the periphery of the central portion 220. The third peripheral portion 223 is located on one side of the second direction orthogonal to the first direction in the periphery of the central portion 220. The fourth peripheral portion 224 is located on the other side of the second direction in the periphery of the central portion 220.

The first peripheral portion 221 is electrically connected to the first electrode 31, the second peripheral portion 222 is electrically connected to the second electrode 32, the third peripheral portion 223 is electrically connected to the third electrode 33, and the fourth peripheral portion 224 is electrically connected to the fourth electrode 34. In the fourth embodiment, the center portion of the cross portion having a cross shape may correspond to the central region of the magnetic sensitive portion 20, and the first to fourth peripheral portions 221 to 224 may correspond to the peripheral region of the magnetic sensitive portion 20.

Alternatively, in the fourth embodiment, the center area may be defined using an auxiliary circle, as in the first embodiment.

Fig. 20 is a diagram illustrating the central region 23 in the fourth embodiment. As shown in fig. 20, an inner region of a circle having a diameter 1/2 with respect to the auxiliary circle 30 and having a geometric center of gravity (exemplified by a + mark) of the magnetism sensing part 20 as a center may be set as the central region 23.

Even with such a configuration, the first to fourth electrodes 31 to 34 cover the first to fourth peripheral portions 221 to 223, which are the peripheral regions of the magnetism sensing portion 20, in a plan view. The first to fourth electrodes 31 to 34 extend from the peripheral region of the magnetism sensing portion 20 to the central portion 220, which is a central region, and a part of the central portion 220 is covered with the first to fourth electrodes 31 to 34. Therefore, the fourth embodiment achieves the same effects as the effects (1) to (5) of the first embodiment.

Hereinafter, the hall element according to the above-described embodiment will be described in detail by way of examples.

[ example 1]

In this embodiment, an ion implantation method is used to form the active layer. First, silicon ions (Si +) are implanted into a semi-insulating GaAs substrate (hereinafter referred to as a "GaAs substrate"). Next, the silicon ions are activated, and a GaAs active layer having n-type conductivity is formed on the GaAs substrate.

Next, a photoresist is applied to the GaAs substrate to form a predetermined pattern, and the GaAs substrate is etched to a predetermined depth using the pattern as a mask. Next, by using a resist stripping liquid or using O₂The photoresist is removed by ashing using plasma, and the magnetic sensitive portion of the hall element is formed.

After the magnetic sensitive portion of the hall element is formed, a photoresist is applied to the GaAs substrate and patterned, and then a metal film is evaporated. After that, the photoresist and the metal film on the photoresist are removed by a lift-off method, and the base electrode is formed. Next, an alloying treatment is performed to obtain ohmic contact between the GaAs substrate and the base electrode.

Thereafter, an insulating film (Si) having a film thickness of 0.3 μm was formed over the entire surface above the GaAs substrate by a plasma CVD method₃N₄)。

Next, an insulating film (Si) of a portion where connection between the base electrode and the electrode is performed is applied₃N₄) Etching is performed, thereby forming an insulating film (Si)₃N₄) A photoresist is coated thereon, and a pattern is formed so as to open a hole at a portion where the above-described connection is ensured (i.e., a contact portion). Then, the photoresist is used as a mask to apply an insulating film (Si)₃N₄) Reactive dry etching is performed, thereby opening the contact portion.

Next, the photoresist is patterned so as to overlap the underlying base electrode, and a metal film is evaporated again on the underlying base electrode. After that, the photoresist and the metal film on the photoresist are removed by a lift-off method, thereby forming a plurality of electrodes. In example 1, each electrode was formed so that the minimum distance between adjacent electrodes was 6.0 μm. In this way, a plurality of GaAs hall elements are formed on one GaAs substrate. After that, the GaAs substrate is diced, thereby producing a plurality of GaAs hall elements that are singulated. Three hall elements were selected from the plurality of hall elements singulated, and an ESD test was performed.

[ example 2]

In example 2, each electrode was formed so that the minimum distance between adjacent electrodes was 8.0 μm. Except for this, a GaAs hall element was manufactured in the same manner as in example 1.

[ example 3]

In example 3, each electrode was formed so that the minimum distance between adjacent electrodes was 9.7 μm. Except for this, a GaAs hall element was manufactured in the same manner as in example 1.

[ example 4]

In example 4, each electrode was formed so that the minimum distance between adjacent electrodes was 4.0 μm. Except for this, a GaAs hall element was manufactured in the same manner as in example 1.

Comparative example 1

In comparative example 1, each electrode was formed so that the minimum distance between adjacent electrodes was 12.0 μm. Except for this, a GaAs hall element was manufactured in the same manner as in example 1.

Comparative example 2

In comparative example 2, each electrode was formed so that the minimum distance between adjacent electrodes was 14.5 μm. Except for this, a GaAs hall element was manufactured in the same manner as in example 1.

Comparative example 3

In comparative example 3, each electrode was formed so that the minimum distance between adjacent electrodes was 16.5 μm. Except for this, a GaAs hall element was manufactured in the same manner as in example 1.

Comparative example 4

In comparative example 4, each electrode was formed so that the minimum distance between adjacent electrodes was 18.5 μm. Except for this, a GaAs hall element was manufactured in the same manner as in example 1.

[ machine mode ESD test ]

In the machine mode ESD test of the hall element, based on the test standard JESD22-a115-a, after charging a charge into a charge-discharge capacitor of 200pF by a variable voltage power supply via a protection resistor of 1M Ω, a switch was switched to set a closed circuit electrically connecting adjacent terminals of the hall element and the charge-discharge capacitor, thereby flowing the charged charge to the hall element. Thus, a test for the electrostatic discharge phenomenon in the assembly process or the like was performed in a virtual manner.

Then, the offset voltage value before the ESD test and the offset voltage value after the ESD test were measured at an input voltage of 3V, and the fluctuation amount thereof was calculated. The results of the tests conducted in examples 1 to 4 and comparative examples 1 to 4 are shown in Table 1 and FIG. 21.

FIG. 21 is a graph showing the results of tests conducted in examples 1 to 4 and comparative examples 1 to 4. In fig. 21, the abscissa represents the inter-electrode distance and the ordinate represents the fluctuation amount Δ Vu of the offset voltage.

As is clear from fig. 21, when the inter-electrode distance is 11 μm or less, the fluctuation amount of the offset voltage is significantly reduced. In addition, it is found that the fluctuation amount of the offset voltage is further reduced particularly when the value is 9 μm or less.

[ Table 1]

< fifth embodiment >

[ Structure ]

(1) Hall element

Fig. 22 is a plan view showing a configuration example of a hall element 500 according to a fifth embodiment of the present invention. Fig. 23 (a) and 23 (b) are cross-sectional views obtained by cutting the hall element 500 shown in fig. 22 along the lines N22-N '22 and O22-O' 22. Fig. 23 (c) is an enlarged cross-sectional view of a portion surrounded by a broken line in fig. 23 (a).

As shown in fig. 22 and fig. 23 (a) to 23 (b), the hall element 500 includes: a substrate 10; a magnetism sensing portion 20 formed on one surface (e.g., upper surface) 10a side of the substrate 10; and first to fourth electrodes 31 to 34, the first to fourth electrodes 31 to 34 being formed on one surface side of the substrate 10 and electrically connected to the magnetism sensing portion 20. The first electrode 31 and the second electrode 32 are input electrodes of the hall element 500, and the third electrode 33 and the fourth electrode 34 are output electrodes of the hall element 500. In each embodiment of the present invention, the outer peripheries of the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 are located inward of the outer periphery of the magnetism sensing portion 20 in a plan view.

(1.1) substrate

The substrate 10 is, for example, a compound semiconductor substrate, and one example of the substrate is a GaAs substrate. The resistivity of the GaAs substrate was 1.0X 10⁵Omega cm or more. The upper limit of the resistivity of the GaAs substrate 10 is not particularly limited, but is 1.0 × 10 by way of example⁹Omega cm or less. The substrate 10 has a rectangular shape in plan view (hereinafter referred to as a planar shape). Examples of the rectangular shape include a square shape, a rectangular shape, a rounded square shape, and a rounded rectangular shape. In addition, the top view means a top view.

(1.2) magnetic sensitive part

The magnetic induction portion 20 is formed on the upper surface 10a of the substrate 10, and has a stepped shape in a cross-sectional view (hereinafter, referred to as a cross-sectional shape). In the fifth embodiment of the present invention, the magnetic induction portion 20 has a rectangular shape in plan view. In the embodiments of the present invention, the position where the magnetic induction portion 20 is formed is not limited to the upper surface 10a of the substrate 10. The magnetism sensing portion (active layer) 20 may be formed partially or entirely inside the upper surface 10a side of the substrate 10. In addition, from the viewpoint of temperature characteristics, the magnetism sensing portion 20 is preferably formed of GaAs. However, the present embodiment is not limited to the structure in which the magnetic sensing portion 20 is formed of GaAs, and, for example, a compound semiconductor such as InSb or InAs may be used.

The magnetic induction portion 20 is a layer having a lower resistance than the substrate 10. The magnetic sensitive part 20 is formed, for example, by a method of implanting impurities such as Si, Sn, S, Se, Te, Ge, or C into the substrate 10 and activating the impurities by heating, or by a method of growing a compound semiconductor containing the impurities on the substrate 10 by an epitaxial growth method such as an MOCVD (Metal Organic Chemical Vapor Deposition) method or an MBE (Molecular Beam Epitaxy) method.

As the n-type impurity (i.e., donor-type impurity) of the n-type GaAs, a known n-type impurity, for example, Si, Ge, Se, or the like can be used. The concentration of the n-type impurity (effective carrier concentration) is not particularly limited, but the effective carrier concentration is preferably 1.0 × 10 from the viewpoint of the output and temperature characteristics of the hall element¹⁴[cm^-3]Above and 1.0X 10¹⁹[cm^-3]Hereinafter, more preferably 1.0 × 10¹⁵[cm^-3]Above and 1.0X 10¹⁸[cm^-3]Hereinafter, more preferably 1.0 × 10¹⁵[cm^-3]Above and 5.0X 10¹⁷[cm^-3]The following. If the effective carrier concentration is within the above range, the temperature dependence of the output is easily suppressed and the absolute value of the output is easily obtained, which is preferable.

The surface layer 22 is formed on the conductive layer 21, and is a GaAs layer having lower conductivity than the conductive layer 21, or a layer including a high-resistance crystal layer such as an AlGaAs or AlAs layer. The film thickness of the surface layer 22 is preferably 150nm or more, preferably 200nm or more, in order to realize a hall element in which variation in sheet resistance is suppressed, and is otherwise 800nm or less, more preferably 600nm or less, from the viewpoint of ease of manufacturing. Furthermore, the surface layer may be absent.

The method for forming the surface layer 22 is not particularly limited, and can be formed by, for example, an ion implantation method or epitaxial growth using an MBE method or an MOCVD method. As a method for obtaining GaAs having lower conductivity than the conductive layer 21 as in the surface layer 22, there can be mentioned a method of making the concentration of impurities lower than the conductive layer 21, a method of intentionally not doping impurities, and the like. In order to directly connect the conductive layer 21 to the first to fourth electrodes 31 to 34 in an ohmic manner, a part of the surface layer 22 may be etched to be thinned or removed.

Fig. 24 is a plan view showing a configuration example of the magnetism sensing portion 20. As shown in fig. 24, in a plan view, the center position 25 of the rectangular magnetic induction portion 20 substantially coincides with the center position of the rectangular substrate 10. In addition, in a plan view, the first side 26 to the fourth side 29 of the outer periphery of the magnetism sensing part 20 are parallel to two sides of the first side 11 to the fourth side 14 of the outer periphery of the substrate 10, respectively. That is, in a plan view, the first side 26 to the fourth side 29 of the outer periphery of the magnetism sensing part 20 are parallel to or perpendicular to the first side 11 to the fourth side 14 of the outer periphery of the substrate 10. More specifically, the first and

third sides

fourth sides

27 and 29 of the outer periphery of the substrate 10. The second and

fourth sides

third sides

26 and 28 of the outer periphery of the substrate 10.

The magnetic sensing portion 20 has a central region 23 including a central position 25 of the magnetic sensing portion 20 in a plan view, and a peripheral region 24 located in the periphery of the central region 23. In the present embodiment, the shape of the central region 23 in plan view is, for example, a perfect circle. The magnetic induction portion 20 has a square shape in plan view, for example. In the present embodiment, when the diameter of the central region 23 is L1 and the length of one side of the outer periphery of the magnetism sensing part 20 (i.e., one of the first side 26 to the fourth side 29) is L2, the ratio of L1 to L2 (L1/L2) is, for example, 1/4 or more and less than 1, or 1/3 or more and 1/2 or less.

In the present embodiment, the central region 23 may have a rectangular shape in a plan view. When the central region 23 is rectangular, one side of the outer periphery of the rectangle corresponds to the above-described L1.

(1.3) electrodes

Fig. 25 is a plan view showing a configuration example of the first electrode 31 to the fourth electrode 34. First, the positional relationship between the first to fourth electrodes 31 to 34 and the magnetism sensing portion 20 will be described.

As shown in fig. 25, the outer peripheries 31e to 34e of the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 are located inward of the outer periphery 20e of the magnetism sensing portion 20 in a plan view. That is, the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 are located inside the region surrounded by the outer periphery e of the magnetism sensing part 20 in a plan view and are located in regions not overlapping with the outer periphery e of the magnetism sensing part 20.

Here, the outer periphery of the magnetic sensitive portion 20 is a contour line that is the outermost side of the magnetic sensitive portion 20 in a plan view. For example, as shown in fig. 23 (a) to 23 (c), when the cross-sectional shape of the magnetic sensitive portion 20 is a stepped shape, there are a contour line (hereinafter, referred to as a "stepped upper contour line") 202 on the upper end side of a side surface (hereinafter, referred to as a "stepped side surface") 201 of the magnetic sensitive portion 20 and a contour line (hereinafter, referred to as a "stepped lower contour line") 203 on the lower end side of the stepped side surface 201 as contour lines when the magnetic sensitive portion 20 is viewed in a plan view. The step upper contour line 202 is a boundary line between the upper surface 20a of the magnetism sensing part 20 and the step side surface 201. The step lower contour line 203 is a boundary line between the step side surface 201 and the upper surface 10a of the substrate 10. In the embodiments of the present invention, the stepped lower contour line 203 corresponds to the outer periphery of the magnetism sensing portion 20.

Therefore, in the embodiments of the present invention, even when the first to fourth electrodes 31 to 34 extend from the upper surface 20a of the magnetism sensing portion 20 to the step side surface 201, they do not extend to the step lower side contour line 203. The step lower side contour lines 203 are exposed from below the first to fourth electrodes 31 to 34.

In each embodiment of the present invention, the first to fourth electrodes 31 to 34 are preferably provided only on the upper surface 20a side of the magnetism sensing portion 20 and not provided extending on the step side surface 201. That is, the step side surface 201 of the magnetism sensing portion 20 is preferably exposed from the lower side of the first electrode 31 to the fourth electrode 34. This further improves wire bondability, which will be described later.

Next, the shapes and the arrangements of the first to fourth electrodes 31 to 34 on the upper surface 20a side of the magnetism sensing portion 20 will be described. As shown in fig. 25, the first electrode 31 and the second electrode 32 face each other in the first direction. In addition, the third electrode 33 and the fourth electrode 34 face each other in a second direction intersecting (e.g., orthogonal to) the first direction in a plan view. Further, on the upper surface side of the magnetism sensing portion 20, the first electrode 31 to the fourth electrode 34 extend from the peripheral region 24 to the central region 23 of the magnetism sensing portion 20, respectively.

As shown in fig. 25, when the separation distance between the first electrode 31 and the second electrode 32 in the first direction (i.e., the separation distance between the extending

portions

33b, 33 c) is D2, D1 and D2 are 1 μm or more and 40 μm or less.

Here, the first corner 31c is a portion included in the extension 31b of the first electrode 31. The second corner portion 32c is a portion included in the extension portion 32b of the second electrode 32. The third corner 33c is a portion included in the extension 33b of the third electrode 33. The fourth corner 34c is a portion included in the extension 34b of the fourth electrode 34. As shown in fig. 25, the first corner portion 31c, the second corner portion 32c, the third corner portion 33c, and the fourth corner portion 34c are disposed adjacent to each other. The first corner 31c is adjacent to the third corner 33c and the fourth corner 34c, the second corner 32c is adjacent to the third corner 33c and the fourth corner 34c, the first corner 31c and the second corner 32c face each other in the first direction, and the third corner 33c and the fourth corner 34c face each other in the second direction.

As shown in fig. 22, the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 are disposed at four corners of the rectangle of the substrate 10. Further, the respective sides of the outer peripheries of the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 are parallel to two sides of the outer periphery of the substrate 10. That is, in a plan view, the respective sides of the outer peripheries of the first to fourth electrodes 34 are parallel to or perpendicular to the first to fourth sides 11 to 14 of the outer periphery of the substrate 10.

As shown in fig. 23, each of the first to fourth electrodes 31 to 34 includes a first metal film 131 electrically connected to the magnetism sensing portion 20 and a second metal film 132 formed on the first metal film 131. That is, the first metal film 131 is a contact region with the magnetic induction portion 20.

Further, an insulating film 40 is formed between the magnetic sensitive portion 20 and the second metal film 132. The insulating film 40 is, for example, a silicon nitride film (Si)₃N₄Film), silicon oxide film (SiO)₂Film), inorganic film (Al)₂O₃) And a polyimide film, a multilayer film in which a plurality of these films are laminated. That is, the insulating film 40 is disposed between the magnetism sensing portion 20 and the first to fourth electrodes when viewed in cross section. The insulating film 40 has openings 401 at positions overlapping the four corners of the rectangle of the magnetism sensing portion 20. The magnetism sensing portion 20 is in contact with the first electrode 31 to the fourth electrode 34 in the opening 401. The insulating film 40 may be formed on the first metal film 131 as shown in fig. 23, may not be formed on the first metal film 131, or may be formed so as to partially enter under the first metal film 131.

(1.4) region for bonding fine metal wire (wire bonding region)

Fig. 26 (a) to 26 (c) are schematic views showing the wire bonding region of the hall element 500, fig. 26 (a) is a plan view, fig. 26 (b) is a sectional view of fig. 26 (a) taken along line P26-P '26, and fig. 26 (c) is a sectional view of fig. 26 (a) taken along line Q26-Q' 26.

As shown in fig. 26 (a) to 26 (c), the first electrode 31 has a first wire bonding region 141 on the upper surface side thereof to which the thin metal wire is bonded. The first metal film 131 constituting the first electrode 31 serves as a contact region where the first electrode 31 is in contact with the magnetism sensing part 20.

In addition, the second electrode 32 has a second wire bonding region 142 on the upper surface side thereof to which the thin metal wire is bonded. The first metal film 131 constituting the second electrode 32 serves as a contact region where the second electrode 32 is in contact with the magnetism sensing part 20.

In addition, the third electrode 33 has a third wire bonding region 143 on its upper surface side to which the thin metal wire is bonded. The first metal film 131 constituting the third electrode 33 serves as a contact region where the third electrode 33 is in contact with the magnetism sensing portion 20.

In addition, the fourth electrode 34 has a fourth wire bonding region 144 on the upper surface side thereof to which the thin metal wire is bonded. The first metal film 131 constituting the fourth electrode 34 serves as a contact region where the fourth electrode 34 contacts the magnetism sensing portion 20.

When viewed in cross section, the insulating film 40 is interposed between the first to fourth electrodes 31 to 34 and the magnetism sensing portion 20 in a region where the thin metal wires are bonded (wire bonding region), and the insulating film 40 has an opening 401 in a region in contact with the magnetism sensing portion 20.

In the region where the thin metal wire is bonded, the magnetism sensing portion 20 has a flat surface with a flat upper surface. The insulating film 40 may be a stress relaxation insulating film.

As described above, the first electrode 31 and the second electrode 32 are input electrodes of the hall element 500, and thus the signal input path 146 of the hall element 500 is between the contact area of the first electrode 31 and the contact area of the second electrode 32. In addition, since the third electrode 33 and the fourth electrode 34 are output electrodes of the hall element 500, a signal output path 145 of the hall element 500 is formed between a contact area of the third electrode 33 and a contact area of the fourth electrode 34.

(2) Hall sensor

Fig. 27 (a) to 27 (d) are cross-sectional views, plan views, bottom views and external views showing structural examples of the hall sensor 700 according to the fifth embodiment of the present invention. Fig. 27 (a) shows a cross section of fig. 27 (b) cut along the broken line R27-R' 27. In fig. 27 (b), the molded member is omitted to avoid complication of the drawing.

As shown in fig. 27 (a) to 27 (d), the hall sensor 700 includes a hall element 500, a lead terminal 520, first to fourth fine metal wires (conductive connecting members) 531 to 534, a protective layer 540, a mold member 550, and a case plating layer 560. The lead terminal 520 includes first to fourth terminal portions 521 to 524.

The hall sensor 700 has, for example, an island-less structure, and has a plurality of terminal portions 521 to 524 for obtaining electrical connection with the outside. As shown in fig. 27 (b), the first to fourth terminal portions 521 to 524 are disposed around the hall element 500.

For example, the first terminal portion 521 and the second terminal portion 522 are disposed so as to face each other with the hall element 500 interposed therebetween, and the third terminal portion 523 and the fourth terminal portion 524 are disposed so as to face each other with the hall element 500 interposed therebetween. A straight line (virtual line) connecting the first terminal portion 521 and the second terminal portion 522 intersects a straight line (virtual line) connecting the third terminal portion 523 and the fourth terminal portion 524 in a plan view. The lead terminals 520 (the first to fourth terminal portions 521 to 524) include metal such as copper (Cu), for example.

The first to fourth fine metal wires 531 to 534 are lead wires that electrically connect the first to fourth electrodes 31 to 34 and the first to fourth terminal portions 521 to 524 of the hall element 500, respectively, and include, for example, gold (Au). As shown in fig. 27 (b), the first fine metal wire 531 connects the first terminal portion 521 to the first electrode 31. The second fine metallic wire 532 connects the second terminal portion 522 and the second electrode 32. The third fine metal wire 533 connects the third terminal portion 523 to the third electrode 33. The fourth fine metal wire 534 connects the fourth terminal portion 524 to the fourth electrode 34. The first to fourth fine metal wires 531 to 534 are bonded to the first to fourth electrodes 31 to 34 of the hall element in the wire bonding region.

The first to fourth wire bonding regions 141 to 144 correspond to partial regions of the upper surfaces of the first to fourth electrodes 31 to 34. The insulating film 40 is interposed between the first to fourth electrodes and the magnetism sensing portion 20 below the bonding regions where the first to fourth fine metal wires 531 to 534 (details will be described later) on the upper surfaces of the first to fourth electrodes 31 to 34 are bonded. Here, the "bonding region" is a region where the first to fourth fine metal wires 531 to 534 actually contact the upper surfaces of the first to fourth electrodes 31 to 34, and is not the spherical diameter of the first to fourth fine metal wires 531 to 534. Therefore, bonding regions where the first to fourth fine metal wires 531 to 534 are bonded to the upper surfaces of the first to fourth electrodes 31 to 34 are present in the first to fourth wire bonding regions 141 to 144. As described above, the contact regions of the first electrode 31 to the fourth electrode 34 are located outside the center positions of the first wire bonding region 141 to the fourth wire bonding region 144, respectively, when viewed from the center position 25 of the magnetism sensing portion 20. Therefore, the first to fourth electrodes 31 to 34 are connected to the magnetism sensing portion 20 outside the bonding regions where the first to fourth fine metal wires 531 to 534 are bonded to the upper surfaces of the first to fourth electrodes 31 to 34. The centers of the contact regions of the first to fourth electrodes 31 to 34 are preferably located outside the centers of the first to fourth electrodes 31 to 34.

As described above, the first metal film 131 is a contact region with the magnetic induction portion 20. An opening 401 of the insulating film 40 is provided in the first metal film 131. Therefore, the opening 401 of the insulating film 40 is disposed outside the bonding region where the first to fourth fine metal wires 531 to 534 are bonded to the upper surfaces of the first to fourth electrodes 31 to 34 when viewed from the center position 25 of the magnetism sensing portion 20. That is, the insulating film 40 has an opening 401 located outside the bonding region in a plan view. The first to fourth electrodes 31 to 34 are in contact with the magnetism sensing portion 20 at the opening 401. Therefore, in a plan view, the regions of the first to fourth electrodes 31 to 34 in contact with the magnetism sensing portion 20 are disposed outside the regions to which the first to fourth fine metal wires 531 to 534 are bonded.

The protective layer 540 covers the surface side of the substrate 10 opposite to the surface on which the first to fourth electrodes 31 to 34 are provided. The protective layer 540 is not particularly limited as long as it can protect the substrate 10, and may be formed of a material having a low thermal conductivitySo as to include at least any one of a conductor, an insulator, and a semiconductor. That is, the protective layer 540 may be a film including any one of a conductor, an insulator, and a semiconductor, or may be a film including two or more of these. As the conductor, for example, a conductive resin such as silver paste can be considered. As the insulator, for example, a thermosetting resin containing an epoxy group and Silica (SiO) as a filler can be considered₂) Insulating paste of (1), silicon nitride, silicon dioxide, etc. As the semiconductor, for example, bonding of an Si substrate, a Ge substrate, or the like can be considered. However, the protective layer 540 is preferably an insulator from the viewpoint of preventing leakage current. The protective layer 540 may have a laminated structure.

The molding member 550 molds the hall element 500, the first to fourth terminal portions 521 to 524, and the first to fourth thin metal wires 531 to 534. In other words, the mold member 550 covers and protects (i.e., resin-seals) the hall element 500, at least the surface side (i.e., the surface on the side connected to the thin metal wires) of the first to fourth terminal portions 521 to 524, and the first to fourth thin metal wires 531 to 534. The molding member 550 is made of, for example, thermosetting resin of epoxy system, and can resist high heat during reflow soldering.

As shown in fig. 27 a and 27 c, at least a part of the first surfaces (e.g., the back surfaces) of the first to fourth terminal portions 521 to 524 and at least a part of the first surface (e.g., the back surface) of the GaAs substrate 10 are exposed from the same surface (e.g., the back surface) of the mold member 550 on the bottom surface side of the hall sensor 700 (i.e., the side mounted on the wiring substrate magnetism sensing portion 20). Here, the first surface of the first to fourth terminal portions 521 to 524 is a surface opposite to the surface connected to the first to fourth fine metal wires 531 to 534 among the plurality of surfaces of the first to fourth terminal portions 521 to 524. The first surface of the GaAs substrate 10 is a surface opposite to the surface on which the first to fourth electrodes 31 to 34 are provided, among the plurality of surfaces of the GaAs substrate 10.

[ act ]

That is, the first terminal 521 is a power supply terminal for supplying a predetermined voltage to the hall element 500. The second terminal portion 522 is a ground terminal portion for supplying a ground potential to the hall element 500. The third terminal portion 523 and the fourth terminal portion 524 are signal extracting terminal portions for extracting the hall electromotive force signal of the hall element 500.

[ production method ]

(1) Method for manufacturing Hall element

Fig. 28 (a) to 28 (e) are sectional views illustrating a method for manufacturing the hall element 500 in the order of steps. As shown in fig. 28 (a), first, the substrate 10 is prepared. The substrate 10 is, for example, a GaAs substrate 10. Next, a donor-type impurity is ion-implanted into a position at a predetermined depth from the surface of the substrate 10. Examples of the donor-type impurity include Si, Sn, S, Se, Te, Ge, and C. Next, the substrate 10 is heated to activate the impurities. As a result, as shown in fig. 28 (b), a conductive layer 21 having a lower electrical resistance than that of the substrate 10 is formed in the substrate 10, and a surface layer 22 is formed on the conductive layer 21. The surface layer 22 has a lower impurity concentration than the conductive layer 21, and is therefore a layer having a higher resistance (i.e., a layer having a lower conductivity) than the conductive layer 21.

The step of activating the impurities may be performed after the step of patterning the substrate 10 shown in fig. 28 (c). Further, the heating step may be performed in combination with other heating steps after the step shown in fig. 28 (c). The formation of the conductive layer 21 is not limited to ion implantation. For example, GaAs containing a high concentration of impurities may be epitaxially grown on the substrate 10 by MOCVD to form the conductive layer 21. In this case, after the conductive layer 21 is formed, the surface layer 22 having a higher resistance than the conductive layer 21 can be formed on the conductive layer 21 by epitaxially growing GaAs containing a low concentration of impurities (or containing no impurities).

Next, the substrate 10 is patterned by using a photolithography technique and an etching technique, and as shown in fig. 28 (c), the magnetic induction portion 20 having a step-like shape in cross section is formed.

Next, as shown in fig. 28 (d), a first metal film 131 is partially formed on the substrate 10 on which the magnetic induction portion 20 is formed. Here, as the first metal film 131, for example, an AuGe film, a Ni film, and an Au film are laminated in this order. The first metal film 131 is formed by, for example, peeling or mask evaporation. The peeling was as follows: the metal film is evaporated on the substrate on which the resist pattern is formed, and then the resist pattern is removed, whereby the metal film remains only on the region of the substrate not covered with the resist pattern. Mask evaporation is the following method: the metal film is deposited on the substrate by a plate having a partial through-hole, and thereby the metal film is deposited only in a region directly below the through-hole of the substrate. After the first metal film 131 is formed, the substrate 10 is heated to alloy the interface between the substrate 10 and the first metal film 131.

Next, as shown in fig. 28 (e), the insulating film 40 is formed in a portion exposed from the first metal film 131 of the substrate 10. The insulating film 40 is, for example, a silicon nitride film. The insulating film 40 is formed, for example, by the following method: an insulating film is formed on the entire upper surface of the substrate 10 by a CVD (Chemical Vapor Deposition) method, and then the insulating film formed on the entire upper surface is patterned using a photolithography technique and an etching technique. Note that, after an insulating film is formed over the entire upper surface of the substrate 10 and patterned to form the insulating film 40, the first metal film 131 may be formed.

Next, as shown in fig. 28 (e), a second metal film 132 is partially formed on the substrate 10 on which the insulating film 40 is formed. Here, as the second metal film 132, for example, a Ti film and an Au film are laminated in this order. The second metal film 132 is formed by, for example, lift-off or mask evaporation.

Then, a protective film (not shown) or the like is formed on the substrate 10. Then, the substrate 10 is cut, and the substrate 10 is singulated for each of the plurality of hall elements 500, i.e., for each hall element 100. Through the above steps, the hall element 500 shown in fig. 22 and the like is completed.

(2) Manufacturing method of Hall sensor

Fig. 29 (a) to 29 (e) and fig. 30 (a) to 30 (d) are a plan view and a cross-sectional view showing a process sequence of the method for manufacturing the hall sensor 700. Note that, in fig. 29 (a) to 29 (e), the blade width of the dicing (i.e., the notch width) is not shown.

As shown in fig. 29 (a), a lead frame 620 is first prepared. The lead frame 620 is a substrate in which a plurality of lead terminals 520 shown in fig. 27 (b) are connected in the vertical direction and the horizontal direction in a plan view.

Next, as shown, one surface of a heat-resistant film 580 as a base material is attached to the back surface of the lead frame 620. An insulating adhesive layer is applied to one surface of the heat-resistant film 580, for example. The adhesive layer is made of, for example, silicone resin as a base material. The lead frame 620 can be easily attached to the heat-resistant film 580 by the adhesive layer. By attaching the heat-resistant film 580 to the back surface side of the lead frame 620, the through region penetrating the lead frame 620 is sealed from the back surface side by the heat-resistant film 580.

Next, as shown in fig. 29 (c), the hall element 500 having the protective layer 540 is placed (i.e., die-bonded) on the surface of the heat-resistant film 580 having the adhesive layer in the region surrounded by the first to fourth terminal portions 521 to 524. Here, the first surface of the substrate 10 is opposed to the surface of the heat-resistant film 580 having the adhesive layer, and die bonding is performed.

Next, as shown in fig. 29 (d), one ends of the first to fourth fine metal wires 531 to 534 are connected to the first to fourth terminal portions 521 to 524, respectively, and the other ends of the first to fourth fine metal wires 531 to 534 are connected to the first to fourth electrodes 31 to 34 of the hall element 500, respectively (that is, wire-bonded). The other ends of the first to fourth fine metal wires 531 to 534 are bonded to the wire bonding regions of the first to fourth electrodes 31 to 34 of the hall element 500.

The wire bonding may be a forward bonding in which a thin metal wire is extended from each electrode of the hall element 500 to each terminal portion of the lead terminal 520, or conversely a reverse bonding in which a thin metal wire is extended from each terminal portion of the lead terminal 520 to each electrode of the hall element 500. The reverse bonding can reduce the loop height after bonding of the thin metal wire as compared with the forward bonding, and therefore can contribute to thinning of the hall element.

Then, as shown in fig. 29 (e), a molding member 550 is formed (i.e., resin molding is performed). The resin molding is performed, for example, using a transfer molding technique.

For example, as shown in fig. 30 (a), a mold 590 including a lower mold 591 and an upper mold 592 is prepared, and a lead frame 620 after wire bonding is disposed in a cavity of the mold 590. Next, the molding member 550 heated and melted is injected and filled into one side of the heat-resistant film 580 in the cavity, which has the surface having the adhesive layer (i.e., the surface to be adhered to the lead frame 620). Thus, the Hall element 500, the lead frame 620 and the thin metal wires 531 to 534 are molded. That is, the hall element 500, at least the surface side of the lead frame 620, and the fine metal wires 531 to 534 are covered and protected by the mold member 550. When the molding member 550 is further heated to be cured, the molding member 550 is removed from the molding die.

Next, as shown in fig. 30 (b), the heat-resistant film 580 is peeled off from the molding member 550. Thereby, the substrate 10 of the hall element 500 is exposed from the molding member 550. Then, as shown in fig. 30 (c), a surface of the lead frame 620 exposed from the mold member 550 (at least a back surface of each of the terminal portions 521 to 524 exposed from the mold member 550) is coated with a plating, thereby forming a case plating layer 560.

Next, as shown in fig. 30 (d), a dicing tape 593 is stuck on the upper surface of the molding member 550 (i.e., the surface of the hall sensor 700 opposite to the surface having the case plating 560). Then, the molding member 550 and the lead frame 620 are cut (i.e., cut) by relatively moving the blade with respect to the lead frame 620, for example, along a virtual two-dot chain line shown in fig. 29 (e). That is, the molding member 550 and the lead frame 620 are cut to be singulated for each of the plurality of hall elements 500. Through the above steps, the hall sensor 700 shown in fig. 27 is completed.

[ Effect of the fifth embodiment ]

The fifth embodiment of the present invention achieves the following effects.

(1) The magnetism sensing portion 20 is formed not only between the electrodes (i.e., between the first electrode 31 and the second electrode 32 and between the third electrode 33 and the fourth electrode 34), but also directly below each of the first electrode 31 to the fourth electrode 34. Therefore, compared to the case where the magnetic sensitive portion is formed only between the electrodes, the space on the substrate 10 can be effectively used, and both the miniaturization of the hall element and the improvement of the S/N (Signal to Noise ratio) can be achieved.

(2) The step side surface 201 of the magnetism sensing portion 20 is formed to be located outside the outer peripheries 31e to 34e of the first electrode 31 to the fourth electrode 34, respectively. Therefore, the wire bondability in the packaging process can be improved, and the yield and the conduction defect can be improved. This can suppress a decrease in the reliability of the hall sensor. In addition, the reliability of the hall sensor can be improved.

Specifically, the step side surface 201 of the magnetic sensing portion 20 formed on the upper surface 10a of the substrate 10 is inclined or stepped from the upper surface 20a of the magnetic sensing portion 20 toward the upper surface 10a of the substrate 10. In the wire bonding step of connecting the first to fourth electrodes 31 to 34 included in the hall element 500 and the first to fourth terminal portions 521 to 524 included in the lead terminal 520 with the first to fourth fine metal wires 531 to 534, respectively, spherical balls are formed at one ends of the first to fourth fine metal wires 531 to 534, respectively, by spark discharge, and the balls are pressed against the first to fourth electrodes 31 to 34 to be bonded to the first to fourth electrodes 31 to 34, respectively, or are vibrated by ultrasonic waves to be bonded to the first to fourth electrodes 31 to 34, respectively.

Here, if the slope structure, which is a stepped side surface of the magnetic induction portion, and the stepped structure are located below the electrode, wire bondability is deteriorated in the wire bonding step. This causes a reduction in the yield of the wire bonding process and a failure in the conduction between the hall element and the terminal portion.

In contrast, according to the fifth embodiment of the present invention, the slope structure or the step structure as the step side surface 201 of the magnetism sensing portion 20 is formed outside the outer peripheries of the first electrode 31 to the fourth electrode 34. That is, the first to fourth electrodes 31 to 34 are formed on the flat upper surface 20a of the magnetism sensing portion 20. As a result, the first electrode 31 to the fourth electrode 34 are also formed flat.

Therefore, the balls formed at the ends of the first to fourth fine metal wires 531 to 534 at the time of wire bonding are pressed against the flat first to fourth electrodes 31 to 34. Therefore, wire bondability is improved, yield is improved, and conduction failure can be improved. Even if Si is formed between the first to fourth electrodes 31 to 34 and the magnetism sensing part 20₃N₄ The insulating film 40 has no step side surface 201 of the magnetism sensing portion 20 under the first electrode 31 to the fourth electrode 34, and thus has good wire bondability.

(3) Further, the contact regions of the first to fourth electrodes 31 to 34 (i.e., the positions where the first metal films 131 are formed) are located outside the centers of the first to fourth wire bonding regions 141 to 144, respectively, as viewed from the center position of the magnetism sensing part 20. Accordingly, as compared with the case where the contact region exists directly below the wire bonding region, the distances between the signal output path 145 and the signal input path 146 can be made longer without increasing the chip area of the hall element, and thus, the improvement in the magnetic detection accuracy of the hall element can be contributed.

In particular, in the hall element 500, the magnetic induction portion 20 has a rectangular shape in plan view, and the contact regions of the first electrode 31 to the fourth electrode 34 are disposed at the corners of the magnetic induction portion 20. This makes it possible to maximize the respective signal output path 145 and signal input path 146 in a limited chip area, and thus greatly contributes to the improvement of the magnetic detection accuracy.

That is, after the insulating film 40 is formed on the magnetic sensitive part 20 having a rectangular shape in a plan view, holes are provided at four positions of the insulating film 40 which overlap with the diagonal corners of the magnetic sensitive part 20. The first to fourth electrodes 31 to 34 are electrically connected to the magnetism sensing portion 20 through the four holes. This allows a current to flow from one end to the other end of the diagonal line of the magnetic induction unit 20. Accordingly, the regions under the first to fourth electrodes 31 to 34 can contribute to the hall electromotive force, and thus the S/N of the hall element can be improved.

(4) In the thinned hall sensor, since the thickness of the mold member on the hall element is small, the electromagnetic wave including light incident on the magnetism sensing portion of the hall element fluctuates the local electrical conductivity of the magnetism sensing portion due to the photoelectric effect. In addition, the hall element generates an offset voltage Vu due to the fluctuation.

In contrast, according to the fifth embodiment, the first to fourth electrodes 31 to 34 extend from the peripheral region 24 to the central region 23 of the magnetism sensing portion 20 in a plan view, and a part of the central region 23 is covered with the first to fourth electrodes 31 to 34.

Here, the metal as the electrode member excellently absorbs the electromagnetic wave containing light. Therefore, the first to fourth electrodes 31 to 34 can shield electromagnetic waves incident on the magnetism sensing portion 20 of the hall element 500, and can suppress local conductivity variation of the magnetism sensing portion 20. This has the effect of suppressing the variation of the offset voltage Vu.

In particular, if the ratio of the total area of the first to fourth electrodes 31 to 34 in the central region to the area of the central region of the magnetism sensing portion 20 in plan view is 10% or more and less than 100%, the effect of suppressing the variation in the offset voltage Vu is high. Preferably 20% or more and 99% or less, and more preferably 40% or more and 95% or less.

(5) In addition, local stress is applied to the magnetism sensing portion due to a filler or the like in a mold member constituting the package. When the stress is received, the electrical conductivity locally fluctuates due to the piezoresistive effect of the semiconductor which is the material of the magnetosensitive portion. As a result, the hall element generates an offset voltage Vu.

In contrast, according to the fifth embodiment, since the metal serving as the electrode member is plastically deformed flexibly according to the stress, the local stress from the mold member 550 can be relaxed, and the local variation in the electrical conductivity of the magnetism sensing portion 20 can be suppressed. This has the effect of suppressing the variation of the offset voltage Vu of the hall element.

(6) The heat generated in the magnetism sensing unit 20 is discharged from the magnetism sensing unit 20 to the outside of the package through the first to fourth electrodes 31 to 34, the first to fourth fine metal wires 531 to 534, and the first to fourth terminal units 521 to 524. The magnetism sensing part 20 is covered with the first to fourth electrodes 31 to 34 made of metal having high conductivity, and thereby a heat extraction path from the magnetism sensing part 20 through the insulating film 40, the first to fourth electrodes 31 to 34, and the first to fourth thin metal wires 531 to 534 is newly increased. This has the effect of improving the heat dissipation characteristics of the hall element.

(7) Further, the insulating film 40 is provided between the magnetism sensing portion 20 and the first to fourth electrodes 31 to 34 when viewed in cross section, and when viewed in cross section, the insulating film 40 is in a region where the first to fourth thin metal wires 531 to 534 are bonded, the insulating film 40 is interposed between the first to fourth electrodes 31 to 34 and the magnetism sensing portion 20, and the opening 401 is provided in a region in contact with the magnetism sensing portion 20, whereby when the first to fourth thin metal wires 531 to 534 are bonded, the upper surface of the magnetism sensing portion 20 is made flat via the insulating film 40 under the region where the first to fourth thin metal wires 531 to 534 are bonded, and therefore, the wire bondability is further improved.

< sixth embodiment >

In the fifth embodiment described above, the case where each of the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 extends from the peripheral region 24 to the central region 23 of the magnetism sensing portion 20 in a plan view is described. However, the present invention is not limited thereto.

Fig. 31 is a plan view showing a configuration example of a hall element 600 according to a sixth embodiment of the present invention. As shown in fig. 31, in the hall element 600 according to the sixth embodiment, the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 are formed only in the peripheral region 24 of the magneto-sensitive portion 20. The first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 do not extend to the central region 23.

Even with such a configuration, the outer periphery 31e of the first electrode 31, the outer periphery 32e of the second electrode 32, the outer periphery 33e of the third electrode 33, and the outer periphery 34e of the fourth electrode 34 are located inward of the outer periphery 20e of the magnetism sensing portion 20 in a plan view. Therefore, the sixth embodiment achieves the same effects as the effects (1) to (7) of the fifth embodiment.

< seventh embodiment >

In the fifth embodiment, the central region 23 of the magnetism sensing part 20 defined by L1 and L2 is described with reference to fig. 24. In the sixth embodiment, the central region 23 can be defined as in the fifth embodiment.

However, in the invention according to the fifth to seventh embodiments, the central region 23 may be defined by a method different from the above.

Fig. 32 is a diagram illustrating the central region 23 in the seventh embodiment. As shown in fig. 32, the central region 23 may be, for example, a circular inner region shown by a broken line. To describe in detail, as shown in fig. 32, in a plan view, a circle having the same center as the geometric center of gravity (illustrated by a + mark) of the magnetism sensing part 20 is defined, and an auxiliary circle 30 having a radius equal to the minimum distance from the center of gravity to the contact region is defined. The central region 23 is defined as an inner region of a circle having a diameter of 1/2 with respect to the auxiliary circle 30 and having the center of gravity as a center. The geometric center of gravity of the magnetic sensitive portion 20 can be determined in a figure surrounded by the boundary between the magnetic sensitive portion 20 and the substrate 10 in a plan view. The contact regions are portions where the first to fourth electrodes 31 to 34 are connected to the magnetism sensing portion 20, respectively.

The central region (for example, a circular inner region shown by a dotted line) 23 is a main region that contributes to the hall effect in the magnetic induction portion 20. The outer side of the central region 23 is referred to as a peripheral region 24. The shape of the central region 23 in plan view is not limited to a circle. The central region 23 may have a rectangular shape in plan view.

As described above, even when the center region 23 is defined by using the auxiliary circle 30, the same effects as the effects (1) to (7) of the fifth embodiment are obtained.

In fig. 32, the center region 23 is defined by using the auxiliary circle 30 for the hall element 500 described in the fifth embodiment, and the center region 23 can be defined by the same method as that for the hall element 600 described in the sixth embodiment.

< example of Hall sensor Structure having Hall element >

Next, the positional relationship between the first to fourth electrodes 31 to 34, the contact regions of the first to fourth electrodes 31 to 34, and the first to fourth wire bonding regions 141 to 144 in the hall sensor 700 (see fig. 7 and 27) including any one of the hall elements according to the first to seventh embodiments described above will be described in detail with reference to fig. 33 and 34.

In fig. 33 and 34, the formation position of the first metal film 131 as a contact region of the first electrode 31 is described as an example, but the formation positions of the contact regions described below are also the same for the second electrode 32 to the fourth electrode 34. In fig. 33 and 34, the first electrode 31 and the magnetism sensing portion 20 are described as being rectangular (square), but the shapes of the first electrode 31 and the magnetism sensing portion 20 are not limited thereto, and may be the shapes described in the above embodiments. Similarly, the shape of the contact region is not limited to the shape described in fig. 33 and 34, and may be the shape described in each of the above embodiments.

First, a first example and a second example of the formation positions of the contact regions will be described. In the first and second examples, the case where the bonding region F extends outward from the center O2 of the first electrode 31 when viewed from the center of the magnetism sensing portion 20 will be described with reference to fig. 33.

(first example)

Fig. 33 illustrates contact regions (first metal films 131a to 131e) formed at a plurality of positions. In the first example, the

first metal films

131a, 131b, and 131c shown in fig. 33 show the positions of the preferable contact regions. In particular, the

first metal films

131a and 131b show the position of a contact region more preferable as a first example, and the first metal film 131a shows the position of a contact region more preferable as a first example. On the other hand, the

first metal films

131b, 131c, and 131d show the positions of contact regions that are not preferable as a second example.

In each of the hall sensors 700 according to the above-described embodiments, the region (contact region) where the first electrode 31 contacts the magnetism sensing portion 20 is located outside the center O1 of the bonding region F where the first thin metal wire 531 (see fig. 7) is bonded, as viewed from the center position 25 of the magnetism sensing portion 20. That is, as the first metal film 131, the

first metal film

131a, 131b, or 131c is provided. Thus, the contact region is located outside the center O1 of the joining region F when viewed from the center position 25 of the magnetism sensing part 20.

Therefore, fluctuation of the offset voltage of the hall element included in the hall sensor 700 can be suppressed.

This is because the contact region is arranged outside the center O1 of the bonding region F, whereby a main region (for example, the central region 23 shown in fig. 4) contributing to the hall effect can be made wide within a limited chip area. By increasing the main region contributing to the hall effect, the influence of the resistance variation per unit area is reduced, and the variation of the offset voltage can be suppressed.

Further, the variation of the offset voltage of the hall element is sensitive to the local resistance variation of the contact region, and the bonding region F causes stress to be generated thereunder, and the semiconductor which is the material of the magnetism sensing portion generates resistance variation due to the piezoresistive effect due to the stress. In particular, the stress generated below the center O1 of the joining region F is large. Therefore, by locating the contact region outside the center O1 of the bonding region F, the stress acting on the contact region can be reduced, and the variation in offset voltage can be suppressed.

Preferably, the center of the region (contact region) where the first electrode 31 contacts the magnetically sensitive part 20 is located outside the center O2 of the first electrode 31, and the center O1 of the region where the first thin metal wire 531 is bonded is located inside the center O2 of the first electrode 31. That is, it is preferable to provide the

first metal film

131a or 131b as the first metal film 131. Thus, the contact region is located outside the center O1 of the bonding region F when viewed from the center position 25 of the magnetism sensing part 20, and the center of the contact region is located outside the center O2 of the first electrode 31.

Therefore, the contact region can be formed at a position away from the center O1 of the bonding region F where the generated stress is particularly large, and the variation in the offset voltage of the hall element can be further reduced.

In addition, in a plan view, a region (contact region) where the first electrode 31 contacts the magnetism sensing portion 20 is preferably disposed outside the bonding region F where the first thin metal wire 531 is bonded. That is, it is preferable to provide the first metal film 131a as the first metal film 131. Thus, the contact region is located outside the center O1 of the bonding region F when viewed from the center position 25 of the magnetism sensing part 20, and the center of the contact region is located outside the center O2 of the first electrode 31 and is arranged outside the bonding region F in plan view.

Therefore, a contact region can be formed outside the bonding region F where the generated stress is large, and the variation in the offset voltage of the hall element can be further suppressed.

(second example)

Fig. 33 illustrates contact regions (first metal films 131a to 131e) formed at a plurality of positions.

In the second example, the

first metal films

131a and 131e shown in fig. 33 show the positions of preferable contact regions. In particular, the first metal film 131a shows a position of a contact region which is more preferable as the second example. On the other hand, the

first metal films

In each of the hall sensors 700 according to the above-described embodiments, the first electrode 31 is connected to the magnetism sensing portion 20 outside the bonding region F where the thin metal wire 531 is bonded. The insulating film 40 has an opening 401 located outside the bonding region F in a plan view, and thus the first electrode 31 is in contact with the magnetism sensing part 20 at the opening 401. That is, the

first metal film

131a or 131e is provided as the first metal film 131. Thereby, the

first metal film

131a or 131e is connected to the magnetism sensing part 20 outside the bonding region F.

Therefore, a contact region can be formed outside the bonding region F where the generated stress is large, and variation in the offset voltage of the hall element can be suppressed. In addition, wire bondability is improved, and the reliability of the hall sensor 700 is improved. This is because the bonding region F is formed in the flat electrode portion by avoiding the step of the opening 40, and the close adhesion of the bonding portion is improved.

Further, it is preferable that the opening 401 (see fig. 2, 23, and the like) of the insulating film 40 is disposed outside the bonding region F to which the thin metal wire 531 is bonded, as viewed from the center position 25 of the magnetism sensing portion 20. That is, it is preferable to provide the first metal film 131a as the first metal film 131. Thus, the first metal film 131a is connected to the magnetism sensing part 20 outside the bonding region F, and the opening 401 of the insulating film 40 is disposed outside the bonding region F when viewed from the center 25 of the magnetism sensing part 20.

Therefore, the main region contributing to the hall effect can be increased, the influence of the resistance variation per unit area can be reduced, and the variation of the offset voltage can be further suppressed.

Next, a third example and a fourth example of the formation positions of the contact regions will be described. In the third and fourth examples, the case where the bonding region F is formed inside the center O2 of the first electrode 31 when viewed from the center of the magnetism sensing portion 20 will be described with reference to fig. 34. The effects of the respective configurations are similar to those of the first and second examples, and therefore, the description thereof is omitted.

(third example)

Fig. 34 illustrates contact regions (first metal films 131Aa to 131D) formed at a plurality of positions. In the third example, the

first metal films

131A, 131B, and 131C shown in fig. 34 show the positions of preferred contact regions. In particular, the first metal film 131A shows a position of a contact region which is more preferable as the first example. On the other hand, the first metal film 131D shows a position of a contact region which is not preferable as the third example.

In each of the hall sensors 700 according to the above-described embodiments, the region (contact region) where the first electrode 31 contacts the magnetism sensing portion 20 is located outside the center O1 of the bonding region F where the first thin metal wire 531 (see fig. 7) is bonded, as viewed from the center position 25 of the magnetism sensing portion 20. That is, the

first metal film

131A, 131B, or 131C is provided as the first metal film 131. Thus, the contact region is located outside the center O1 of the joining region F when viewed from the center position 25 of the magnetism sensing part 20.

Preferably, the center of the region (contact region) where the first electrode 31 contacts the magnetically sensitive part 20 is located outside the center O2 of the first electrode 31, and the center O1 of the region where the first thin metal wire 531 is bonded is located inside the center O2 of the first electrode 31. That is, it is preferable to provide the first metal film 131A as the first metal film 131. Thus, the contact region is located outside the center O1 of the bonding region F when viewed from the center position 25 of the magnetism sensing part 20, and the center of the contact region is located outside the center O2 of the first electrode 31.

In addition, in a plan view, a region (contact region) where the first electrode 31 contacts the magnetism sensing portion 20 is preferably disposed outside the bonding region F where the first thin metal wire 531 is bonded. That is, it is preferable to provide the

first metal film

131A or 131B as the first metal film 131. Thus, the contact region is located outside the center O1 of the bonding region F when viewed from the center position 25 of the magnetism sensing part 20, and is arranged outside the bonding region F in plan view.

Further, it is more preferable that the first metal film 131A is provided as the first metal film 131. Thus, the contact region is located outside the center O1 of the bonding region F when viewed from the center position 25 of the magnetism sensing part 20, and the center of the contact region is located outside the center O2 of the first electrode 31 and is arranged outside the bonding region F in plan view.

In each of the hall sensors 700 according to the above-described embodiments, the first electrode 31 is connected to the magnetism sensing portion 20 outside the bonding region F where the thin metal wire 531 is bonded. That is, the

first metal film

131A, 131B, or 131D is provided as the first metal film 131. Thereby, the

first metal film

131A, 131B, or 131D is connected to the magnetism sensing part 20 outside the bonding region F.

Further, it is preferable that the opening 401 (see fig. 2, 23, and the like) of the insulating film 40 is disposed outside the bonding region F to which the thin metal wire 531 is bonded, as viewed from the center position 25 of the magnetism sensing portion 20. That is, it is preferable to provide the

first metal film

131A or 131B as the first metal film 131. Thus, the

first metal film

131A or 131B is connected to the magnetism sensing part 20 outside the bonding region F, and the opening 401 of the insulating film 40 is disposed outside the bonding region F when viewed from the center 25 of the magnetism sensing part 20.

< lens Module >

Next, a lens module using the hall sensor 700 according to the first to seventh embodiments will be described. Fig. 35 (a) shows a lens module 8a for hand shake correction, and fig. 35 (b) shows a lens module 8b for auto-focusing.

As shown in fig. 35 (a) and 35 (b), the

lens modules

8a and 8b include any one of the hall sensors 700 according to the first to seventh embodiments, a lens holder 81 to which the magnet 80 is attached, and a driving coil 82 that moves the magnet based on a hall electromotive force signal that is an output signal output from an external terminal of the hall sensor 700. The hall sensor 700 according to the first to seventh embodiments can be made thin by a molding member, and therefore the hall sensor 700 itself can be made thin and can accurately detect magnetism by suppressing offset variation. Therefore, the

lens modules

8a and 8b of the present embodiment using any one of the hall sensors 700 according to the first to seventh embodiments can be reduced in size and can perform accurate position detection. In the

lens modules

8a and 8b according to the present embodiment, the hall sensor 700 detects the magnetic field of the magnet 80 attached to the lens holder 81, and based on an output signal corresponding to the detected magnetic field, a drive current is caused to flow to the drive coil 82. Thus, the lens module 8a can perform camera shake correction control with high accuracy, and the lens module 8b can perform autofocus control with high accuracy. Further, since the

lens modules

8a and 8b according to the present embodiment are thinned, the hall element (not shown) and the magnet 80 in the hall sensor 700 can be positioned close to each other, and magnetic detection can be performed with higher accuracy.

< other means >

The technical idea of the present invention is not determined by the embodiments and examples described above. Based on the knowledge of those skilled in the art, the embodiments and examples of the present invention may be modified in design, or the embodiments and examples of the present invention may be arbitrarily combined, and the modified embodiments are included in the technical idea of the present invention.

Description of the reference numerals

8a, 8 b: a lens module; 10: a substrate; 10 a: an upper surface; 20: a magnetism sensing part; 20 e: an outer periphery (of the magnetically sensitive portion); 21: a conductive layer; 22: a surface layer; 23: a central region; 24: a peripheral region; 25: a central position; 29: an auxiliary circle; 31: a first electrode; 31 a: a main portion (of the first electrode); 31 b: an extension (of the first electrode); 31 c: a first corner portion; 32: a second electrode; 32 a: a main portion (of the second electrode); 32 b: an extension (of the second electrode); 32c, the ratio of: a second corner portion; 33: a third electrode; 33 a: a main portion (of the third electrode); 33 b: an extension (of the third electrode); 33 c: a third corner portion; 34: a fourth electrode; 34 a: a main portion (of the fourth electrode); 34 b: an extension (of a fourth electrode); 34 c: a fourth corner portion; 40: an insulating film; 80: a magnet; 81: a lens holder; 82: a drive coil; 100. 200, 300, 400, 500, 600: a Hall element; 120: a main magnetism sensing portion; 121: a first extension portion; 122: a second extension portion; 123: a third extension portion; 124: a fourth extension portion; 126: a first diagonal line; 127: a second diagonal line; 131: a first metal film; 132: a second metal film; 141: a first wire bonding region; 142: a second wire bonding region; 143: a third wire bonding region; 144: a fourth wire bond region; 145: a signal output path; 146: a signal input path; 201: a step side; 202: step upper side contour lines; 203: the contour line of the lower side of the step; 220: a central portion; 221: a first peripheral portion; 222: a second peripheral portion; 223: a third peripheral portion; 224: a fourth peripheral portion; 401: an opening part; 520: a lead terminal; 521: a first terminal portion; 522: a second terminal portion; 523: a third terminal portion; 524: a fourth terminal portion; 531: a first thin metal wire; 532: a second metal thin wire; 533: a third metallic thin wire; 534: a fourth thin metal wire; 540: a protective layer; 550: a molded member; 560: coating the shell; 580: a heat-resistant film; 590: molding a mold; 591: a lower die; 592: an upper die; 593: cutting the belt; 620: a lead frame; 700: and a Hall sensor.

Claims

1. A Hall element is provided with:

a substrate;

a magnetic induction part formed on one surface side of the substrate;

a first electrode and a second electrode formed on the one surface side and electrically connected to the magnetism sensing portion, the first electrode and the second electrode facing each other in a first direction; and

a third electrode and a fourth electrode formed on the one surface side and electrically connected to the magnetism sensing portion, the third electrode and the fourth electrode facing each other in a second direction intersecting the first direction in a plan view,

wherein the first electrode, the second electrode, the third electrode, and the fourth electrode each extend from a peripheral region of the magnetic induction portion to a central region of the magnetic induction portion,

the ratio of the total area of the first to fourth electrodes in the central region to the area of the central region of the magnetic induction portion is 40% to 95% in a plan view.

2. The Hall element of claim 1,

the first electrode, the second electrode, the third electrode, and the fourth electrode are each rectangular in shape when viewed from above,

a first corner portion of the first electrode, a second corner portion of the second electrode, a third corner portion of the third electrode, and a fourth corner portion of the fourth electrode are respectively located above the magnetic induction portion,

the first corner portion and the second corner portion face each other in the first direction, and the third corner portion and the fourth corner portion face each other in the second direction.

3. The Hall element according to claim 2,

a center portion of a region surrounded by the first corner portion, the second corner portion, the third corner portion, and the fourth corner portion overlaps a center portion of the magnetism sensing portion in a plan view.

4. The Hall element according to claim 2,

the substrate has a rectangular shape in plan view,

the first electrode, the second electrode, the third electrode, and the fourth electrode are disposed at four corners of a rectangle of the substrate,

each of the respective outer peripheries of the first electrode, the second electrode, the third electrode, and the fourth electrode is parallel to two of four outer peripheries of the substrate.

5. The Hall element of claim 1,

a minimum distance between adjacent ones of the first to fourth electrodes is 2 μm or more and 11 μm or less in a plan view.

6. The Hall element of claim 1,

further comprising an insulating film disposed between the magnetic induction portion and the first to fourth electrodes when viewed in cross section,

the insulating film has openings at positions overlapping with four corners of the rectangle of the magnetic induction part,

the magnetic induction portion is in contact with the first to fourth electrodes at the opening.

7. A Hall sensor is provided with:

the Hall element of any one of claims 1 to 6;

a first terminal portion;

a second terminal portion;

a third terminal portion;

a fourth terminal portion;

a first fine metal wire connecting the first electrode and the first terminal portion;

a second thin metal wire connecting the second electrode and the second terminal portion;

a third fine metal wire connecting the third electrode and the third terminal portion; and

a fourth fine metal wire connecting the fourth electrode and the fourth terminal portion,

wherein each of the first to fourth electrodes has a region to which the first to fourth fine metal wires are bonded, and a region in which the first to fourth electrodes are in contact with the magnetism sensing portion,

the first to fourth electrodes are located outside the center of the bonding region where the first to fourth thin metal wires are bonded, when viewed from the center of the magnetic induction portion.

8. The Hall sensor according to claim 7,

the insulating film is interposed between the first to fourth electrodes and the magnetism sensing portion in a region where the first to fourth fine metal wires are bonded, and has an opening in a region where the first to fourth electrodes and the magnetism sensing portion are in contact, when viewed in cross section.

9. Hall sensor according to claim 7 or 8,

the centers of the areas of the first to fourth electrodes in contact with the magnetic induction portion are located outside the centers of the first to fourth electrodes,

the center of the region to which the thin metal wire is bonded is located inward of the centers of the first to fourth electrodes.

10. Hall sensor according to claim 7 or 8,

in a plan view, regions where the first to fourth electrodes are in contact with the magnetism sensing portion are disposed outside a bonding region where the thin metal wires are bonded.

11. A lens module is provided with:

the hall sensor of any one of claims 7 to 10;

a lens holder to which a magnet is mounted; and

and a driving coil that moves the magnet based on output signals output from the plurality of terminal portions of the hall sensor.