JP6612887B2 - Hall element, Hall sensor, lens module - Google Patents

Description

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

Conventionally, magnetic sensors have been applied to many magnetic sensor products such as current detection devices and position detection devices. As a typical example of a magnetic sensor, there is a Hall element using the Hall effect.
The Hall element generally has a magnetic sensing part, a current electrode pair for passing a current through the magnetic sensing part, and an output electrode pair for detecting Hall electromotive force, and is detected from the output electrode pair. The magnitude and direction of the magnetism applied to the magnetic sensing part are detected from the Hall electromotive force.
Patent Document 1 discloses a Hall element including a semi-insulating GaAs substrate, an N-type operation layer, an N + contact layer, an ohmic junction metal film, a bonding metal film, and an insulating film. .
Patent Document 2 discloses a Hall element in which the four inner corner portions of a cross-shaped Hall element are formed in a shape in which the corners are not diagonally cut but obliquely chamfered.

Patent Document 3 discloses a pellet, a plurality of lead terminals arranged around the pellet, a plurality of electrode portions of the pellet, and a plurality of fine metal wires that electrically connect the lead terminals, respectively, and the back surface of the pellet Hall sensor in which at least a part of the insulating paste and at least a part of the back surface of each lead terminal are respectively exposed from the mold resin. Is disclosed.
In Patent Document 4, in a Hall sensor using a Hall chip in which a cross-shaped magnetic sensing portion is formed on a substrate and an electrode is formed on each of the cross-shaped arms, the opposing portions between adjacent electrodes are parallel to each other. In addition, a Hall sensor is disclosed in which the parallel lengths of these facing portions are set to a dimension equal to or larger than the value obtained by subtracting the distance between the facing portions from 40 μm.

JP 60-175471 A JP-A-1-298354 International Publication No. 2014/091714 Pamphlet JP 2000-294853 A

In the conventional technique, the offset voltage of the Hall element may fluctuate.
An object of the present invention is to provide a Hall element, a Hall sensor, and a lens module that can suppress fluctuations in offset voltage.

  In order to solve the above-described problem, a Hall element according to an aspect of the present invention includes a substrate, a magnetic sensing portion formed on one surface side of the substrate, and the magnetic sensitivity formed on the one surface side. A first electrode and a second electrode facing each other in a first direction, and electrically connected to the magnetosensitive portion formed on the one surface side, and A third electrode and a fourth electrode facing each other in a second direction that intersects the direction in plan view, the first electrode, the second electrode, the third electrode, and the fourth electrode Each of the electrodes extends from a peripheral region of the magnetic sensitive part to a central region of the magnetic sensitive part.

  A Hall element according to another aspect of the present invention includes a substrate, a magnetic sensing portion formed on one surface side of the substrate, and electrically connected to the magnetic sensing portion formed on the one surface side. The first electrode and the second electrode facing each other in the first direction are formed on the one surface side and electrically connected to the magnetic sensing portion, and intersect the first direction in plan view. A third electrode and a fourth electrode facing each other in a second direction, and the shape of the first electrode, the second electrode, the third electrode, and the fourth electrode in plan view is Each is rectangular, the first corner of the first electrode, the second corner of the second electrode, the third corner of the third electrode, and the fourth 4th corner | angular part which this electrode has is each located above the said magnetic sensing part, It is characterized by the above-mentioned.

  A Hall element according to another aspect of the present invention is formed on a substrate, on one surface side of the substrate, a magnetically sensitive portion having a rectangular shape in plan view, and formed on the one surface side to form the sensor. A first electrode and a second electrode facing each other in a first direction, electrically connected to the magnetic part, and formed on the one surface side and electrically connected to the magnetic sensitive part; A third electrode and a fourth electrode facing each other in a second direction that intersects the first direction in plan view, and the first electrode, the second electrode, and the third electrode in plan view The outer periphery of each of the fourth electrodes is located inside the outer periphery of the magnetic sensing part.

  A Hall sensor according to one embodiment of the present invention includes the Hall element, the first terminal portion, the second terminal portion, the third terminal portion, the fourth terminal portion, and the first electrode. And a first metal wire connecting the first terminal part, a second metal wire connecting the second electrode and the second terminal part, the third electrode and the third A third metal thin wire connecting the terminal portion of the second metal wire, and a fourth metal thin wire connecting the fourth electrode and the fourth terminal portion. Each has a region where the first to fourth thin metal wires are joined, and a region where the first to fourth electrodes are in contact with the magnetic sensing portion, and the first to fourth electrodes The region in contact with the magnetic sensing part is located outside the center of the joining region where the first to fourth metal fine wires are joined as seen from the center of the magnetic sensing part. To.

  A Hall sensor according to another aspect of the present invention is formed on a substrate, a magnetic sensitive part formed on one surface side of the substrate, an insulating film formed on the magnetic sensitive part, and the insulating film. And a terminal portion connected to the other end of the thin metal wire, and the shape of the magnetic sensing portion is formed on the substrate. The mesa shape is formed, and the insulating film is interposed between the electrode and the magnetic sensing portion below the bonding region where the thin metal wire on the upper surface of the electrode is bonded. It connects with the said magnetic sensing part outside the joining area | region where a metal fine wire is joined.

  A Hall sensor according to another aspect of the present invention includes the Hall element, the first terminal portion, the second terminal portion, the third terminal portion, the fourth terminal portion, and the first terminal portion. A first thin metal wire connecting the electrode and the first terminal portion; a second thin metal wire connecting the second electrode and the second terminal portion; the third electrode; A third metal wire connecting the third terminal portion, a fourth metal wire connecting the fourth electrode and the fourth terminal portion, at least a part of the Hall element, It is provided with the mold member which seals at least one part of a 4th terminal part, and the said 1st-4th metal fine wire.

  The Hall sensor according to another aspect of the present invention includes a substrate, a magnetic sensing portion formed on one surface side of the substrate, and electrically connected to the magnetic sensing portion formed on the one surface side. The first electrode and the second electrode facing each other in the first direction are formed on the one surface side and electrically connected to the magnetic sensing portion, and intersect the first direction in plan view. A third electrode and a fourth electrode facing each other in the second direction; an insulating film disposed between the magnetically sensitive portion and the first to fourth electrodes in a cross-sectional view; and a plurality of terminal portions A thin metal wire connecting the first to fourth electrodes and the plurality of terminal portions, the first electrode, the second electrode, the third electrode, and the fourth electrode. Each of which has a region where the fine metal wires are joined and a region in contact with the magnetic sensing part, as viewed from the center of the magnetic sensing part, A region in contact with the magnetic sensing portion is located outside the center of the region to which the metal fine wire is joined, and the insulating film has the first to fourth in the region to which the metal fine wire is joined in a cross-sectional view. It has an opening in a region that is interposed between the electrode and the magnetic sensing part and is in contact with the magnetic sensing part.

  A lens module according to an aspect of the present invention includes a hall coil, a lens holder to which a magnet is attached, and a drive coil that moves the magnet based on output signals from the plurality of terminal portions of the hall sensor. And.

  According to each aspect of the present invention, fluctuations in offset voltage can be suppressed.

It is a figure which shows the structural example of the Hall element 100 which concerns on 1st Embodiment. It is the figure which cut | disconnected Hall element 100 shown in FIG. 1 by the A1-A'1 line and the B1-B'1 line. It is a figure which shows the structural example of the magnetic sensing part 20 which concerns on 1st Embodiment. It is a figure which illustrates the center area | region 23 in 1st Embodiment. It is a figure which shows the structural example of the 1st-4th electrodes 31-34. It is a schematic diagram which shows the 1st-4th wire bonding area | regions 141-144. It is a figure which shows the structural example of the Hall sensor 700 which concerns on 1st Embodiment. FIG. 3 is a diagram illustrating a method for manufacturing the Hall element 100 in the order of steps. It is a figure shown in order of a process which shows a manufacturing method of hall sensor 700. It is a figure shown in order of a process which shows a manufacturing method of hall sensor 700. It is a figure which shows the structural example of the Hall element 200 which concerns on 2nd Embodiment. It is the figure which cut | disconnected Hall element 200 shown in FIG. 11 by the F11-F'11 line and the G11-G'11 line. It is a figure which shows the structural example of the Hall element 300 which concerns on 3rd Embodiment. It is the figure which cut | disconnected Hall element 300 shown in FIG. 13 by the H13-H'13 line and the J13-J'13 line. It is a figure which shows the structural example of the magnetic sensing part 20 which concerns on 3rd Embodiment. It is a figure which illustrates the center area | region 23 in 3rd Embodiment. It is a figure which shows the structural example of the Hall element 400 which concerns on 4th Embodiment. It is the figure which cut | disconnected the Hall element shown in FIG. 17 by the K17-K'17 line and the M17-M'17 line. It is a figure which shows the structural example of the magnetic sensing part 20 which concerns on 4th Embodiment. It is a figure which illustrates the center area | region 23 in 4th Embodiment. It is a figure which shows the test result done in Examples 1-4 and Comparative Examples 1-4. It is a figure which shows the relationship between the distance between electrodes, and the variation | change_quantity of offset voltage. It is a figure which shows the structural example of the Hall element 500 which concerns on 5th Embodiment. It is the figure which cut | disconnected Hall element 500 shown in FIG. 22 by the N1-N'1 line and the O1-O'1 line. It is a figure which shows the structural example of the magnetic sensing part 20 which concerns on 5th Embodiment. It is a figure which shows the structural example of the 1st-4th electrodes 31-34. It is a schematic diagram which shows the 1st-4th wire bonding area | regions 141-144. It is a figure which shows the structural example of the Hall sensor 700 which concerns on 5th Embodiment. It is a figure which shows the manufacturing method of Hall element 500 in order of a process. It is a figure shown in order of a process which shows a manufacturing method of hall sensor 700. It is a figure shown in order of a process which shows a manufacturing method of hall sensor 700. It is a figure which shows the structural example of the Hall element 600 which concerns on 6th Embodiment. It is a figure which illustrates the center area | region 23 in 7th Embodiment. It is a figure explaining the formation position of the contact area | region and wire bonding area | region in the Hall sensor 700 provided with the Hall element which concerns on 1st to 7th embodiment. It is a figure explaining the formation position of the contact area | region and wire bonding area | region in the Hall sensor 700 provided with the Hall element which concerns on 1st to 7th embodiment. It is a figure which shows schematic structure of the lens modules 8a and 8b using the Hall sensor 700 which concerns on 1st to 7th Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the same reference numerals are given to portions corresponding to each other in the drawings to be described below, and description of the overlapping portions will be omitted as appropriate. Further, the embodiment of the present invention exemplifies a configuration for embodying the technical idea of the present invention, and specifies the material, shape, structure, arrangement, dimensions, etc. of each part as follows. Not. The technical idea of the present invention can be variously modified within the technical scope defined by the claims described in the claims.

<First Embodiment>
〔Constitution〕
(1) Hall element FIG. 1: is a top view which shows the structural example of the Hall element 100 which concerns on 1st Embodiment of this invention. 2A and 2B are cross-sectional views of the Hall element 100 shown in FIG. 1 cut along lines A1-A′1 and B1-B′1.
As shown in FIG. 1, FIG. 2A and FIG. 2B, the Hall element 100 includes a substrate 10 and a magnetosensitive portion 20 formed on one surface (for example, an upper surface) 10a side of the substrate 10. And first to fourth electrodes 31 to 34 that are formed on one surface side of the substrate 10 and are electrically connected to the magnetic sensing unit 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 a compound semiconductor substrate, for example, and there is a GaAs substrate as an example. The resistivity of the GaAs substrate is 1.0 × 10 ⁵ Ω · cm or more. The upper limit of the resistivity of the GaAs substrate 10 is not particularly limited, but for example, it is 1.0 × 10 ⁹ Ω · cm or less. The shape of the substrate 10 in plan view (hereinafter referred to as “planar shape”) is rectangular. Examples of the rectangular shape include a quadrangular shape, a rectangular shape, a rounded square shape, and a rounded rectangular shape. The plan view means a top view.

(1.2) Magnetic Sensing Section The magnetic sensing section 20 is formed on the upper surface 10a of the substrate 10 and its shape in cross-sectional view (hereinafter referred to as “cross-sectional shape”) is a mesa shape. Alternatively, the magnetic sensitive part 20 may be formed inside the substrate 10. In the first embodiment of the present invention, the planar shape of the magnetic sensitive unit 20 is rectangular. In each embodiment of the present invention, the formation position of the magnetic sensitive part 20 is not limited to the upper surface 10 a of the substrate 10. A part or all of the magnetosensitive part (active layer) 20 may be formed inside the substrate 10 on the upper surface 10a side. The magnetic sensitive part 20 is preferably formed of GaAs from the viewpoint of temperature characteristics. However, the present embodiment is not limited to the configuration in which the magnetically sensitive portion 20 is formed using GaAs as a material, and for example, a compound semiconductor such as InSb or InAs can also be used.

The magnetic sensitive part 20 is a layer having a lower resistance than the substrate 10. For example, the magnetic sensing unit 20 may be formed by implanting impurities such as Si, Sn, S, Se, Te, Ge, or C into the substrate 10 and performing activation by heating, or by using a compound semiconductor containing the above impurities by MOCVD (Metal It is formed by growing it on the substrate 10 by an epitaxial growth method by an organic chemical vapor deposition (MBD) method, an MBE (molecular beam epitaxy) method, or the like.
For example, the magnetic sensitive part 20 has a conductive layer 21 and a surface layer 22 formed on the conductive layer 21. The conductive layer 21 is made of n-type GaAs formed on the substrate 10. The film thickness of the conductive layer 21 is not particularly limited, but is preferably 50 nm or more and 2000 nm or less, and more preferably 100 nm or more and 1000 nm or less from the viewpoint of ease of manufacture.

As the n-type impurity (that is, donor-type impurity) of n-type GaAs, a known one can be used, and for example, Si, Ge, Se, or the like can be used. The concentration of n-type impurities (effective carrier concentration) is not particularly limited, but the effective carrier concentration is 1.0 × 10 ¹⁴ [cm ⁻³ ] or more and 1.0 × 10 ¹⁹ from the viewpoint of the output and temperature characteristics of the Hall element. [Cm ⁻³ ] or less is preferable, and 1.0 × 10 ¹⁵ [cm ⁻³ ] or more and 1.0 × 10 ¹⁸ [cm ⁻³ ] or less is more preferable, and 1.0 × 10 ¹⁵ [cm ³ ] or less. More preferably, it is not less than cm ⁻³ ] and not more than 5.0 × 10 ¹⁷ [cm ⁻³ ]. If the effective carrier concentration is within the above range, it is preferable because the temperature dependency of the output is suppressed and the absolute value of the output can be easily obtained.
As a method for forming the conductive layer 21, there is a method in which an impurity is ion-implanted into the substrate 10 to form an n-type GaAs layer near or inside the surface of the substrate 10. As another method for forming the conductive layer 21, there is a method of epitaxially growing a GaAs thin film on the substrate 10 by doping an impurity ion by MBE (molecular beam epitaxy) method or MOCVD (metal organic chemical vapor deposition) method. Can be mentioned.

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 made of a high resistance crystal such as AlGaAs or AlAs. The film thickness of the surface layer 22 is 150 nm or more, preferably 200 nm or more in order to realize a Hall element in which variation in sheet resistance is suppressed, and from the viewpoint of manufacturability, preferably 800 nm or less. More preferably, it is 600 nm or less. Note that the surface layer may be omitted.
The method for forming the surface layer 22 is not particularly limited, and can be formed, for example, by ion implantation, or epitaxial growth using MBE or MOCVD. Examples of a method for obtaining GaAs having lower conductivity than the conductive layer 21 like the surface layer 22 include a method of setting an impurity concentration lower than that of the conductive layer 21 and a method of not intentionally doping impurities. Further, in order to directly ohmic-connect the conductive layer 21 and the first to fourth electrodes 31 to 34, a part of the surface layer 22 may be etched to be thinned or removed.

  FIG. 3 is a plan view illustrating a configuration example of the magnetic sensing unit 20. As shown in FIG. 3, the center position 25 of the rectangular magnetic sensing part 20 substantially coincides with the center position of the rectangular substrate 10 in plan view. Further, in plan view, the first to fourth sides 26 to 29 on the outer periphery of the magnetic sensing unit 20 are respectively parallel to two of the first to fourth sides 11 to 14 on the outer periphery of the substrate 10. ing. That is, in plan view, the first to fourth sides 26 to 29 on the outer periphery of the magnetic sensing unit 20 are parallel or perpendicular to the first to fourth sides 11 to 14 on the outer periphery of the substrate 10. More specifically, the first side 11 and the third side 13 on the outer periphery of the magnetic sensing unit 20 are parallel to the first side 26 and the third side 28 on the outer periphery of the substrate 10 and the first side 11 and the third side 28 on the outer periphery of the substrate 10. It is perpendicular to the second side 27 and the fourth side 29. The second side 12 and the fourth side 14 on the outer periphery of the magnetic sensing unit 20 are parallel to the second side 27 and the fourth side 29 on the outer periphery of the substrate 10 and the first side 26 and the outer side of the substrate 10. It is perpendicular to the third side 28.

In addition, the magnetic sensing unit 20 includes a central region 23 including the central position 25 of the magnetic sensing unit 20 in a plan view, and a peripheral region 24 positioned around the central region 23. The planar shape of the central region 23 is, for example, a perfect circle shape. The planar shape of the magnetic sensitive unit 20 is, for example, a square shape.
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 an inner region of a circle indicated by a broken line, for example. More specifically, as shown in FIG. 4, in a plan view, it is a circle having the same center as the geometric center of gravity (illustrated by + sign) of the magnetic sensing unit 20, and the minimum distance from the center of gravity to the contact region is An auxiliary circle 30 is defined as a radius. The central region 23 is an inner region of a circle having a diameter of ½ with respect to the auxiliary circle 30 and centering on the center of gravity. The geometric center of gravity of the magnetic sensing unit 20 can be obtained from a figure surrounded by the boundary between the magnetic sensing unit 20 and the substrate 10 in plan view. The contact region is a portion where the first to fourth electrodes 31 to 34 and the magnetic sensing portion 20 are connected to each other.
The central region (for example, the inner region of a circle indicated by a broken line) 23 is a main region that contributes to the Hall effect, particularly in the magnetic sensitive portion 20. Further, the outside of the central region 23 is set as a peripheral region 24.
Note that the planar shape of the central region 23 may be rectangular.

(1.3) Electrode FIG. 5 is a plan view showing a configuration example of the first to fourth electrodes 31 to 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 that intersects (for example, is orthogonal to) the first direction in plan view. The first to fourth electrodes 31 to 34 extend from the peripheral region 24 to the central region 23 of the magnetic sensing unit 20, respectively.
That is, the first electrode 31 has a main part 31 a and an extending part 31 b extending from the main part 31 a to the central region 23 of the magnetic sensitive part 20. The second electrode 32 includes a main part 32 a and an extension part 32 b extending from the main part 32 a to the central region 23 of the magnetic sensitive part 20. The third electrode 33 has a main part 33 a and an extending part 33 b extending from the main part 33 a to the central region 23 of the magnetic sensitive part 20. The fourth electrode 34 has a main portion 34 a and an extending portion 34 b extending from the main portion 34 a to the central region 23 of the magnetic sensitive portion 20.

As shown in FIG. 5, the distance between the first electrode 31 and the second electrode 32 in the first direction (that is, the distance between the extension portions 31b and 32b) is D1, and the distance in the second direction is When the distance between the third electrode 33 and the fourth electrode 34 (that is, the distance between the extending portions 33b and 33c) is D2, D1 and D2 are 1 μm or more and 40 μm or less, respectively.
The shape and arrangement of the first to fourth electrodes 31 to 34 will be described more specifically with examples.
The planar shapes of the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 are each rectangular. In addition, the first corner 31 c included in the first electrode 31, the second corner 32 c included in the second electrode 32, the third corner 33 c included in the third electrode 33, and the fourth The fourth corner portion 34 c of the electrode 34 is positioned above the magnetic sensing portion 20.

  Here, the first corner portion 31 c is a portion included in the extending portion 31 b of the first electrode 31. The second corner part 32 c is a part included in the extension part 32 b of the second electrode 32. The third corner portion 33 c is a portion included in the extension portion 33 b of the third electrode 33. The fourth corner part 34 c is a part included in the extension part 34 b 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 arranged 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 portion 31c and the second corner portion 32c face each other in the first direction, and the third corner portion 33c and the fourth corner portion 34c face each other in the second direction.

In plan view, 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 with the center position of the magnetic sensing unit 20. Yes. Further, in a plan view, the outer periphery of each of the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 is a region surrounded by the outer periphery of the magnetic sensing unit 20 (that is, the first electrode To a region surrounded by the fourth sides 26 to 29).
As shown in FIG. 1, the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 are respectively disposed at four rectangular corners of the substrate 10. The outer sides of each of the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 are parallel to two of the four sides of the outer periphery of the substrate 10. It has become. That is, each side of the outer periphery of the first to fourth electrodes 34 is parallel or perpendicular to the first to fourth sides 11 to 14 of the outer periphery of the substrate 10 in plan view.

As shown in FIG. 2, the first to fourth electrodes 31 to 34 are respectively formed on the first metal film 131 that is electrically connected to the magnetic sensing unit 20 and on the first metal film 131. Second metal film 132 formed. That is, the first metal film 131 serves as a contact region for the magnetic sensitive part 20. An insulating film 40 is formed between the magnetic sensitive part 20 and the second metal film 132. The insulating film 40 is, for example, a silicon nitride film (Si ₃ N ₄ film), a silicon oxide film (SiO ₂ film), an inorganic film (Al ₂ O ₃ ), or a polyimide film, and is a multilayer film in which a plurality of these films are stacked. is there. Note that the insulating film 40 may be formed on the first metal film 131 as shown in FIG. 2 or may not be formed on the first metal film 131, and may be formed under the first metal film 131. It may be formed in a part.
In the Hall element of the present embodiment, the minimum distance between adjacent electrodes of the plurality of electrodes is preferably 2 μm or more and 11 μm or less in plan view. This minimum distance is more preferably 4 μm or more and 11 μm or less, further preferably 4 μm or more and less than 10 μm, and further preferably 5 μm or more and 9 μm or less. The minimum distance between adjacent electrodes is the minimum distance between all the electrodes.

(1.4) Area where metal fine wires are connected (wire bonding area)
FIGS. 6A to 6C are schematic views showing wire bonding regions in the Hall element 100, FIG. 6A is a plan view, and FIG. 6B is a view of FIG. FIG. 6C is a cross-sectional view taken along line D5-D′5 of FIG. 6A.
As shown in FIGS. 6A to 6C, the first electrode 31 has a first wire bonding region 141 to which a fine metal wire is bonded on the upper surface side. 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 magnetic sensitive part 20.

The second electrode 32 has a second wire bonding region 142 to which a fine metal wire is bonded on the upper surface side. 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 magnetic sensitive part 20.
The third electrode 33 has a third wire bonding region 143 to which a fine metal wire is bonded on the upper surface side. The first metal film 131 constituting the third electrode 33 becomes a contact region where the third electrode 33 is in contact with the magnetic sensitive part 20.
The fourth electrode 34 has a fourth wire bonding region 144 to which a fine metal wire is bonded on the upper surface side. The first metal film 131 constituting the fourth electrode 34 becomes a contact region where the fourth electrode 34 is in contact with the magnetic sensitive part 20.

That is, the contact regions of the first to fourth electrodes 31 to 34 are located outside the center positions of the first to fourth wire bonding regions 141 to 144 when viewed from the center position 25 of the magnetic sensing unit 20. Each is located.
As described above, since the first electrode 31 and the second electrode 32 are input electrodes of the Hall element 100, the Hall element is between the contact region of the first electrode 31 and the contact region of the second electrode 32. A signal input path 146 at 100 is formed. Further, since the third electrode 33 and the fourth electrode 34 are output electrodes of the Hall element 100, a signal between the contact region of the third electrode 33 and the contact region of the fourth electrode 34 is a signal in the Hall element 100. The output path 145 becomes.

(2) Hall sensor FIGS. 7A to 7D are a cross-sectional view, a plan view, a bottom view, and an external view showing a configuration example of the Hall sensor 700 according to the first embodiment of the present invention. FIG. 7A shows a cross section obtained by cutting FIG. 7B along a broken line E7-E′7. Further, in FIG. 7B, the mold member is omitted in order to avoid complication of the drawing.
As shown in FIGS. 7A to 7D, the Hall sensor 700 includes a Hall element 100, a lead terminal 520, first to fourth metal thin wires (conductive connection members) 531 to 534, A protective layer 540, a mold member 550, and an exterior plating layer 560 are provided. Further, the lead terminal 520 has first to fourth terminal portions 521 to 524.
The hall sensor 700 has, for example, an islandless structure, and includes a plurality of terminal portions 521 to 524 for obtaining electrical connection with the outside. As shown in FIG. 7B, the first to fourth terminal portions 521 to 524 are arranged around the Hall element 100.

For example, the first terminal portion 521 and the second terminal portion 522 are arranged 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 formed as holes. They are arranged so as to face each other with the element 100 interposed therebetween. Then, a straight line (virtual line) connecting the first terminal portion 521 and the second terminal portion 522 and a straight line (imaginary line) connecting the third terminal portion 523 and the fourth terminal portion 524 are seen in a plan view. Cross at. The lead terminal 520 (first to fourth terminal portions 521 to 524) is made of a metal such as copper (Cu), for example.
The first to fourth thin metal wires 531 to 534 are conductive wires that electrically connect the first to fourth electrodes 31 to 34 included in the Hall element 100 and the first to fourth terminal portions 521 to 524, respectively. For example, it is made of gold (Au). As shown in FIG. 7B, the first thin metal wire 531 connects the first terminal portion 521 and the first electrode 31. The second thin metal wire 532 connects the second terminal portion 522 and the second electrode 32. The third thin metal wire 533 connects the third terminal portion 523 and the third electrode 33. The fourth thin metal wire 534 connects the fourth terminal portion 524 and 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 a partial region on the upper surface of the first to fourth electrodes 31 to 34. Below the joining region where the first to fourth thin metal wires 531 to 534 (details will be described later) on the upper surfaces of the first to fourth electrodes 31 to 34 are joined, the first to fourth electrodes and the magnetic sensing are provided. An insulating film 40 is interposed between the portions 20. Here, the “joining region” is a region where the first to fourth thin metal wires 531 to 534 are actually in contact with the upper surfaces of the first to fourth electrodes 31 to 34, and the first to fourth It is not the ball diameter of the fine metal wires 531 to 534. For this reason, the junction area | region where the 1st-4th metal fine wires 531-534 join to the upper surface of the 1st-4th electrodes 31-34 exists in the 1st-4th wire bonding area | regions 141-144. As described above, the contact regions of the first to fourth electrodes 31 to 34 are more than the center positions of the first to fourth wire bonding regions 141 to 144 when viewed from the center position 25 of the magnetic sensing unit 20. Each is located outside. Therefore, the first to fourth electrodes 31 to 34 are 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, and the magnetic sensitive part. 20.

  Further, as described above, the first metal film 131 serves as a contact region for the magnetic sensitive portion 20. On the first metal film 131, an opening 401 (see FIG. 2) of the insulating film 40 is provided. For this reason, the opening 401 of the insulating film 40 is joined to the upper surfaces of the first to fourth electrodes 31 to 34 by the first to fourth thin metal wires 531 to 534 when viewed from the central position 25 of the magnetic sensing unit 20. It arrange | positions outside the joining area | region to do. That is, the insulating film 40 has the opening 401 located outside the bonding region in a top view. The first to fourth electrodes 31 to 34 are in contact with the magnetic sensing unit 20 at the opening 401. Therefore, the area | region where the 1st-4th electrodes 31-34 contact the magnetic sensing part 20 is arrange | positioned outside the area | region where the 1st-4th metal fine wires 531-534 are joined.

The protective layer 540 covers the surface 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 made of 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, an epoxy-based thermosetting resin and an insulating paste containing silica (SiO ₂ ) as a filler, silicon nitride, silicon dioxide, or the like can be considered. As the semiconductor, for example, bonding of a Si substrate or a Ge substrate can be considered. However, from the viewpoint of preventing leakage current, the protective layer 540 is preferably an insulator. The protective layer 540 may have a stacked structure.

The mold member 550 molds the Hall element 100, the first to fourth terminal portions 521 to 524, and the first to fourth metal thin wires 531 to 534. In other words, the mold member 550 includes the Hall element 100, at least the surface side of the first to fourth terminal portions 521 to 524 (that is, the surface connected to the metal thin wire), and the first to fourth metals. The thin wires 531 to 534 are covered and protected (that is, resin-sealed). The mold member 550 is made of, for example, an epoxy thermosetting resin and can withstand high heat during reflow.
As shown in FIGS. 7A and 7C, the first to fourth terminal portions 521 to 524 are arranged on the bottom surface side of the Hall sensor 700 (that is, the side mounted on the wiring board magnetic sensing portion 20). At least a part of the first surface (for example, the back surface) and at least a part of the first surface (for example, the back surface) of the GaAs substrate 10 are exposed from the same surface (for example, the back surface) of the mold member 550, respectively. Yes. Here, the 1st surface of the 1st-4th terminal parts 521-524 is the 1st-4th metal thin wire 531-among the several surfaces which the 1st-4th terminal parts 521-524 have, respectively. This is the surface opposite to the surface connected to 534. 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 exterior plating layer 560 is formed on the back surface of the terminal portions 521 to 524 exposed from the mold member 550. The exterior plating layer 560 is made of, for example, tin (Sn).

[Operation]
In the case of detecting magnetism (magnetic field) using the Hall sensor 700 described above, for example, the first terminal portion 521 is connected to the power supply potential (+) and the second terminal portion 522 is set to the ground potential (GND). By connecting, current flows from the first terminal portion 521 to the second terminal portion 522. Then, a 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 / negative of the Hall output voltage VH.
That is, the first terminal portion 521 is a power supply terminal portion that supplies a predetermined voltage to the Hall element 100. The second terminal portion 522 is a ground terminal portion that supplies a ground potential to the Hall element 100. The third terminal portion 523 and the fourth terminal portion 524 are signal extraction terminal portions for extracting the Hall electromotive force signal of the Hall element 100.

〔Production method〕
(1) Method for Manufacturing Hall Element FIGS. 8A to 8E are cross-sectional views showing a method for manufacturing the Hall element 100 in the order of steps. As shown in FIG. 8A, first, a substrate 10 is prepared. The substrate 10 is, for example, a GaAs substrate 10. Next, donor-type impurities are 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. 8B, a conductive layer 21 having a lower 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. Since the surface layer 22 has a lower impurity concentration than the conductive layer 21, it becomes a layer having a higher resistance than the conductive layer 21 (that is, a layer having low conductivity).

  The step of activating the impurities may be performed after the patterning step of the substrate 10 shown in FIG. Moreover, you may perform by combining with the other heating process after the process shown in FIG.8 (c). The formation of the conductive layer 21 is not limited to ion implantation. For example, the conductive layer 21 may be formed by epitaxially growing GaAs containing impurities at a high concentration on the substrate 10 by MOCVD. In this case, following the formation of the conductive layer 21, GaAs containing impurities at a low concentration (or not containing impurities) is epitaxially grown to form a surface layer having a higher resistance than the conductive layer 21 on the conductive layer 21. 22 can be formed.

Next, the substrate 10 is patterned by using a photolithography technique and an etching technique to form the magnetically sensitive portion 20 having a mesa shape in cross-sectional view as shown in FIG.
Next, as shown in FIG. 8D, a first metal film 131 is partially formed on the substrate 10 on which the magnetic sensitive portion 20 is formed. Here, for example, an AuGe film, an Ni film, and an Au film are stacked in this order as the first metal film 131. The first metal film 131 is formed by, for example, lift-off or mask vapor deposition. Lift-off is a method in which a metal film is deposited on a substrate on which a resist pattern is formed, and then the resist pattern is removed, so that the metal film is left only on a region not covered with the resist pattern on the substrate. Mask vapor deposition is a method of depositing a metal film only on a region immediately below the through hole of the substrate by depositing a metal film on the substrate through a plate in which the through hole is partially formed. 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 illustrated in FIG. 8E, the insulating film 40 is formed on the portion of the substrate 10 exposed from below the first metal film 131. The insulating film 40 is, for example, a silicon nitride film. The insulating film 40 is formed by forming an insulating film on the entire upper surface of the substrate 10 by, for example, a CVD (Chemical Vapor Deposition) method, and then using the photolithography technique and the etching technique to form the insulating film formed on the entire upper surface. It is formed by patterning. Note that the first metal film 131 may be formed after an insulating film is formed on the entire top surface of the substrate 10 and patterned to form the insulating film 40.

Next, as shown in FIG. 8E, a second metal film 132 is partially formed on the substrate 10 on which the insulating film 40 is formed. Here, for example, a Ti film and an Au film are stacked in this order as the second metal film 132. Further, the second metal film 132 is formed by, for example, lift-off or mask vapor deposition.
Thereafter, a protective film (not shown) or the like is formed on the substrate 10. Then, the substrate 10 is diced, and the substrate 10 is separated into pieces 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 FIGS. 9A to 9E and FIGS. 10A to 10D are a plan view and a cross-sectional view showing the manufacturing method of the Hall sensor 700 in the order of steps. is there. In FIG. 9A to FIG. 9E, the illustration of the dicing blade width (ie, the kerf width) is omitted.
As shown in FIG. 9A, first, a lead frame 620 is prepared. The lead frame 620 is a substrate in which a plurality of lead terminals 520 shown in FIG. 7B are connected in the vertical direction and the horizontal direction in plan view.

  Next, as illustrated in FIG. 9B, for example, one surface of the heat resistant film 580 is attached to the back side of the lead frame 620 as a base material. For example, an insulating adhesive layer is applied to one surface of the heat resistant film 580. The adhesive layer is based on, for example, silicon resin as its component. This adhesive layer makes it easy to attach the lead frame 620 to the heat resistant film 580. By sticking the heat resistant film 580 to the back surface side of the lead frame 620, the penetration region through which the lead frame 620 penetrates is closed with the heat resistant film 580 from the back surface side.

Next, as shown in FIG.9 (c), the hole which has the protective layer 540 in the area | region enclosed by the 1st-4th terminal parts 521-524 among the surfaces which have the adhesion layer of the heat resistant film 580. The element 100 is mounted (that is, die bonding is performed). Here, die bonding is performed with the first surface of the substrate 10 facing the surface having the adhesive layer of the heat resistant film 580.
Next, as shown in FIG.9 (d), the end of the 1st-4th metal fine wires 531-534 is connected to the 1st-4th terminal parts 521-524, respectively, and the 1st-4th metal The other ends of the thin wires 531 to 534 are connected to the first to fourth electrodes 31 to 34 of the Hall element 100 (that is, wire bonding is performed).

The wire bonding may be forward bonding performed by extending a thin metal wire from each electrode of the Hall element 100 toward each terminal portion of the lead terminal 520, and conversely, from each terminal portion of the lead terminal 520 to the Hall element 100. Reverse bonding may be performed by extending a thin metal wire to each electrode. Inverse bonding can reduce the height of the loop of the Hall element because the loop height after bonding of the fine metal wires can be made lower than that of forward bonding.
Then, as shown in FIG. 9E, a mold member 550 is formed (that is, resin molding is performed). This resin mold is performed using, for example, a transfer mold technique.

  For example, as shown in FIG. 10A, a mold die 590 including a lower die 591 and an upper die 592 is prepared, and a lead frame 620 after wire bonding is disposed in the cavity of the mold die 590. . Next, the mold member 550 heated and melted is injected into the cavity and the side of the heat-resistant film 580 having the adhesive layer (that is, the surface bonded to the lead frame 620) and filled. Thus, the Hall element 100, the lead frame 620, and the fine 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 mold member 550 is further heated and cured, the mold member 550 is removed from the mold.

Next, as shown in FIG. 10B, the heat resistant film 580 is peeled from the mold member 550. As a result, the substrate 10 of the Hall element 100 is exposed from the mold member 550. Then, as shown in FIG. 10C, exterior plating is applied to the surface exposed from the mold member 550 of the lead frame 620 (at least the back surface exposed from the mold member 550 of each terminal portion 521 to 524). Then, the exterior plating layer 560 is formed.
Next, as shown in FIG. 10D, a dicing tape 593 is attached to the upper surface of the mold member 550 (that is, the surface opposite to the surface having the exterior plating layer 560 of the Hall sensor 700). Then, for example, along the virtual two-dot chain line shown in FIG. 9E, the blade is moved relative to the lead frame 620 to cut the mold member 550 and the lead frame 620 (that is, dicing is performed). Do). That is, the mold member 550 and the lead frame 620 are diced for each of the plurality of Hall elements 100 to be singulated. Through the above steps, the Hall sensor 700 shown in FIG. 7 is completed.

[Effects of First Embodiment]
(1) In a thin Hall sensor, since the thickness of the mold member on the Hall element is thin, an electromagnetic wave including light incident on the magnetic sensing part of the Hall element photoelectrically converts the local conductivity of the magnetic sensing part. Fluctuate depending on the effect. Also, this variation causes an offset voltage Vu in the Hall element.
On the other hand, according to the first embodiment, the first to fourth electrodes 31 to 34 extend from the peripheral region 24 of the magnetic sensitive part 20 to the central region 23 in plan view, and A part 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 the four corners of the rectangular substrate 10 to the central region 23 of the magnetic sensitive unit 20. And in this center area | region 23, each extension part 31b-34b of the 1st-4th electrodes 31-34 is each arrange | positioned closely, and the clearance gap between adjacent electrodes is narrow. Accordingly, a part of the central region 23 of the magnetic sensitive unit 20 is covered with the first to fourth electrodes 31 to 34.

Here, the metal which is an electrode member absorbs electromagnetic waves including light very well. Therefore, the first to fourth electrodes 31 to 34 can shield the electromagnetic wave incident on the magnetic sensing part 20 of the Hall element 100, and can suppress local conductivity fluctuations in the magnetic sensing part 20. This has the effect of suppressing fluctuations in the offset voltage Vu.
In particular, when the ratio of the total area on the central region of the first to fourth electrodes 31 to 34 to the area of the central region of the magnetic sensing unit 20 in a plan view is 10% or more and less than 100%, the offset voltage Vu. Highly effective in suppressing fluctuations. This ratio is preferably 20% or more and 99% or less, and more preferably 40% or more and 95% or less.
Moreover, it is preferable that the ratio of the area of the effective region under the 1st-4th electrodes 31-34 with respect to the total area of the effective region of the magnetic sensing part 20 is 40% or more and 99% or less by planar view. . Here, the “area of the effective region” is the first to fourth of the areas of the magnetic sensing unit 20 in contact with the magnetic sensing unit 20 and the first to fourth electrodes 31 to 34 in plan view. The area excluding the total area of the contact area.

(2) Further, local stress is applied to the magnetically sensitive portion by the filler in the mold member constituting the package. In response to the stress, local fluctuations in conductivity occur due to the piezoresistive effect of the semiconductor that is the magnetically sensitive material. As a result, an offset voltage Vu is generated in the Hall element.
On the other hand, according to the first embodiment, since the metal that is the electrode member is plastically deformed flexibly by the stress, the local stress from the mold member 550 is relaxed, and the local conductivity in the magnetic sensitive portion 20 is reduced. Variation can be suppressed. This has the effect of suppressing fluctuations in the offset voltage Vu of the Hall element.

(3) The heat generated in the magnetic sensing unit 20 is generated from the magnetic sensing unit 20 through the first to fourth electrodes 31 to 34, the first to fourth metal wires 531 to 534, and the first to fourth terminals. Heat is discharged out of the package through the parts 521 to 524. Since the magnetic sensitive part 20 is covered with the first to fourth electrodes 31 to 34 made of metal having high conductivity, the insulating film 40, the first to fourth electrodes 31 to 34, and the first one are provided from the magnetic sensitive part 20. -The waste heat path through the 4th metal fine wires 531-534 newly increases. This has the effect of improving the exhaust heat characteristics of the Hall element.

(4) Further, when viewed from the center position of the magnetic sensing unit 20, the contact regions of the first to fourth electrodes 31 to 34 (that is, the positions where the first metal film 131 is formed) It is located outside the center of the wire bonding regions 141 to 144, respectively. As a result, the distance between the signal output path 145 and the signal input path 146 can be increased without increasing the chip area of the Hall element as compared with the case where the contact area is present immediately below the wire bonding area. This can contribute to improvement of the magnetic detection accuracy of the element.
In particular, in the Hall element 100, the planar shape of the magnetic sensing unit 20 is rectangular, and the contact regions of the first to fourth electrodes 31 to 34 are arranged at the corners of the magnetic sensing unit 20, respectively. As a result, the signal output path 145 and the signal input path 146 can be maximized within a limited chip area, which can greatly contribute to the improvement of the magnetic detection accuracy.

(5) Unlike the electrostatic discharge (human model ESD) caused by the human body, the machine-induced electrostatic discharge (machine model ESD) in the assembly process causes a severe discharge in a very short time. Specifically, in the electrostatic discharge caused by the human body, the accumulated electric charge is applied to the Hall element via the human body (high resistance). Therefore, it is equivalent to an RC circuit, and it takes time associated with a large time constant for the discharge to be transmitted. On the other hand, since the electrostatic discharge caused by the machine is applied to the Hall element through the machine (low resistance or wiring), the discharge is instantaneously transmitted to the Hall element. Thus, the electrostatic discharge caused by the human body and the electrostatic discharge caused by the machine are completely different.
When this machine-induced discharge current flows to the magnetic sensing portion of the Hall element, it is heated rapidly and the characteristics of the Hall element change.

In the first embodiment, when the minimum distance between adjacent electrodes of a plurality of electrodes is 11 μm or less in plan view, the discharge current directly passes from the electrodes to the adjacent electrodes without passing through the magnetic sensitive part. A flowing path is created. Thereby, the influence on the magnetic sensitive part by the discharge current can be reduced, and the ESD countermeasure is sufficient. As described above, the present inventors can take a countermeasure against the machine-induced ESD by reducing the distance between the electrodes and forming a path through which a discharge current flows from the electrode to the electrode. Was found.
In the first embodiment, when the minimum distance between adjacent electrodes of a plurality of electrodes is 2 μm or more in plan view, it is possible to suppress leakage current from flowing from the electrode to the adjacent electrode.
As described above, the formation of a leakage current path can be prevented, the ESD countermeasure can be improved, and the offset voltage fluctuation of the Hall element can be satisfactorily suppressed.

Second Embodiment
In the first embodiment, the outer periphery of each of the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 is surrounded by the outer periphery of the magnetic sensing unit 20 in plan view. The case where it is located inside the region has been described. However, the present invention is not limited to this.
FIG. 11 is a plan view showing a configuration example of the Hall element 200 according to the second embodiment of the present invention. 12A and 12B are cross-sectional views of the Hall element 200 shown in FIG. 11 cut along lines F11-F′11 and G11-G′11. As shown in FIGS. 11, 12A, and 12B, in the Hall element 200 according to the second embodiment, the first electrode 31, the second electrode 32, and the third electrode in a plan view. At least a part of the outer periphery of each of the 33 and the fourth electrodes 34 may be located outside the region surrounded by the outer periphery of the magnetic sensing unit 20. Also in the second embodiment, a central region may be defined using an auxiliary circle, as in the first embodiment.
Even in such a configuration, the first to fourth electrodes 31 to 34 extend from the peripheral region 24 of the magnetic sensing unit 20 to the central region 23 in a plan view, and a part of the central region 23 is the first. 1 to 4th electrodes 31 to 34 are covered. Accordingly, the second embodiment has the same effects as the effects (1) to (5) of the first embodiment.

<Third Embodiment>
In said 1st, 2nd embodiment, the case where the planar shape of the magnetic sensing part 20 was a rectangular shape was demonstrated. However, the present invention is not limited to this.
FIG. 13 is a plan view showing a configuration example of the Hall element 300 according to the third embodiment of the present invention. FIGS. 14A and 14B are cross-sectional views of the Hall element 300 shown in FIG. 13 cut along lines H13-H′13 and J13-J′13. FIG. 15 is a plan view illustrating a configuration example of the magnetic sensing unit 20 according to the third embodiment.

As shown in FIGS. 13 to 15, the magnetic sensing unit 20 includes a main magnetic sensing unit 120 having a rectangular planar shape, and first to fourth extending outward from four corners of the main magnetic sensing unit 120. You may provide the extension parts 121-124. In a plan view, the first extension part 121 and the second extension part 122 are located on the extension line of the first diagonal line 126 of the main magnetic sensing part 120, respectively. In addition, the third extension portion 123 and the fourth extension portion 124 are respectively located on the extension line of the second diagonal 127 of the main magnetic sensing portion 120.
As shown in FIG. 13, the first extension portion 121 is electrically connected to the first electrode 31. The second extension part 122 is electrically connected to the second electrode 32. The third extension part 123 is electrically connected to the third electrode 33. The fourth extension portion 124 is electrically connected to the fourth electrode 34. Also in the third embodiment, as in the first embodiment, the central region may be defined using an auxiliary circle.

FIG. 16 is a diagram illustrating the central region 23 in the third embodiment. As shown in FIG. 16, in the third embodiment as well, in the same way as in the first embodiment, the geometrical center of gravity (20) of the diameter of the auxiliary circle 30 is 1/2 with respect to the auxiliary circle 30. An inner area of a circle centered at (+) is a central area 23.
Even in such a configuration, the first to fourth electrodes 31 to 34 extend from the peripheral region 24 of the magnetic sensing unit 20 to the central region 23 in a plan view, and a part of the central region 23 is the first. 1 to 4th electrodes 31 to 34 are covered. Therefore, the third embodiment has the same effects as the effects (1) to (5) of the first embodiment.

<Fourth embodiment>
In said 1st, 2nd embodiment, the case where the planar shape of the magnetic sensing part 20 was a rectangular shape was demonstrated. In the third embodiment, the case where the main magnetic sensing part 120 has a rectangular shape has been described. However, the present invention is not limited to this.
FIG. 17 is a plan view showing a configuration example of the Hall element 400 according to the fourth embodiment of the present invention. FIGS. 18A and 18B are cross-sectional views of the Hall element shown in FIG. 17 cut along lines K17-K′1 and M17-M′17. FIG. 19 is a plan view illustrating a configuration example of the magnetic sensing unit 20 according to the fourth embodiment.
As shown in FIGS. 17 to 19, the planar shape of the magnetic sensitive unit 20 is a cross (that is, a cross) shape, and includes a central part 220 and first to fourth peripheral parts 221 positioned around the central part 220. ˜224.

In plan view, the first peripheral portion 221 is located on one side in the first direction in the periphery of the central portion 220. 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 part 223 is located on one side in the second direction orthogonal to the first direction in the periphery of the central part 220. The fourth peripheral portion 224 is located on the other side in 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, and the third peripheral portion 223 is the third electrode The fourth peripheral portion 224 is electrically connected to the fourth electrode 34 and is electrically connected to the electrode 33. In the fourth embodiment, the central portion that is a cross-shaped intersection corresponds to the central region of the magnetic sensing unit 20, and the first to fourth peripheral portions 221 to 224 correspond to the peripheral region of the magnetic sensing unit 20. Also good.
Alternatively, in the fourth embodiment, as in the first embodiment, the central region may be defined using an auxiliary circle.

FIG. 20 is a diagram illustrating the central region 23 in the fourth embodiment. As shown in FIG. 20, the inner area of a circle centering on the geometric center of gravity (illustrated by + sign) of the magnetic sensing portion 20 is ½ the diameter of the auxiliary circle 30. The central region 23 may be used.
Even in such a configuration, the first to fourth electrodes 31 to 34 cover the first to fourth peripheral portions 221 to 223 that are the peripheral regions of the magnetic sensitive unit 20 in a plan view. The first to fourth electrodes 31 to 34 extend from the peripheral region of the magnetic sensing unit 20 to the central portion 220 that is the central region, and a part of the central portion 220 is the first to fourth electrodes 31. It is covered with ~ 34. Therefore, the fourth embodiment has the same effects as the effects (1) to (5) of the first embodiment.

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

[Example 1]
In this embodiment, the active layer is formed using an ion implantation method. First, silicon ions (Si +) were implanted on a semi-insulating GaAs substrate (hereinafter referred to as “GaAs substrate”). Next, the silicon ions were activated to form a GaAs active layer having n-type conductivity on the GaAs substrate.
Next, a photoresist is applied on the GaAs substrate to form a predetermined pattern, and the GaAs substrate is etched to a predetermined depth using this as a mask. Next, the photoresist was removed by an ashing method using a resist stripping solution or O ₂ plasma to form a magnetically sensitive portion of the Hall element.

After forming the magnetic sensing portion of the Hall element, a photoresist was applied and patterned on the GaAs substrate, and then a metal film was deposited. Thereafter, the metal film on the photoresist and the photoresist was removed by a lift-off method to form a base electrode. Next, an alloying treatment was performed to obtain ohmic contact between the GaAs substrate and the base electrode.
Thereafter, an insulating film (Si ₃ N ₄ ) having a thickness of 0.3 μm was formed on the entire upper surface of the GaAs substrate by plasma CVD.
Next, in order to etch a portion of the insulating film (Si ₃ N ₄ ) where the base electrode and the electrode are connected, a photoresist is applied on the insulating film (Si ₃ N ₄ ) to ensure the above connection ( That is, a pattern was formed so that a hole was opened in the contact portion. Thereafter, the contact portion was opened by performing reactive dry etching on the insulating film (Si ₃ N ₄ ) using this photoresist as a mask.

  Next, the photoresist was patterned so as to overlap with the lower base electrode, and a metal film was deposited again on the lower base electrode. Thereafter, the metal film on the photoresist and the photoresist was removed by a lift-off method to form a plurality of electrodes. In Example 1, each electrode was formed so that the minimum distance between adjacent electrodes was 6.0 μm. Thus, a large number of GaAs Hall elements were formed on one GaAs substrate. Thereafter, the GaAs substrate was diced to produce a large number of individual GaAs Hall elements. Three were selected from a large number of separated Hall elements, and an ESD test was conducted.

[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 model ESD test]
The machine model ESD test of the Hall element is based on the test standard JESD22-A115-A, and after charging the charge / discharge capacitor of 200 pF through a 1 MΩ protective resistor with a variable voltage power supply, the switch is changed over. By forming a closed circuit in which the charge / discharge capacitor is electrically connected between adjacent terminals, the charged electric charge was allowed to flow through the Hall element. As a result, a test was conducted to simulate the electrostatic discharge phenomenon in the assembly process.
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 3 V, and the fluctuation amount was calculated. The test results performed in Examples 1 to 4 and Comparative Examples 1 to 4 are shown in Table 1 and FIG.

FIG. 21 is a diagram illustrating test results obtained in Examples 1 to 4 and Comparative Examples 1 to 4. In FIG. 21, the horizontal axis represents the distance between the electrodes, and the vertical axis represents the variation amount ΔVu of the offset voltage.
According to FIG. 21, it can be seen that when the inter-electrode distance is 11 μm or less, the amount of fluctuation of the offset voltage is significantly reduced. Further, it can be seen that the fluctuation amount of the offset voltage is further reduced particularly at 9 μm or less.

<Fifth Embodiment>
〔Constitution〕
(1) Hall element FIG. 22: is a top view which shows the structural example of the Hall element 500 which concerns on 5th Embodiment of this invention. FIGS. 23A and 23B are cross-sectional views of the Hall element 500 shown in FIG. 22 cut along lines N22-N′22 and O22-O′22. FIG. 23C is an enlarged cross-sectional view of a portion surrounded by a broken line in FIG.

  As shown in FIGS. 22 and 23A to 23B, the Hall element 500 includes a substrate 10 and a magnetosensitive portion 20 formed on one surface (for example, an upper surface) 10a side of the substrate 10. And first to fourth electrodes 31 to 34 that are formed on one surface side of the substrate 10 and are electrically connected to the magnetic sensing unit 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 periphery of each of the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 is located on the inner side of the outer periphery of the magnetic sensing unit 20 in plan view. To do.

(1.1) Substrate The substrate 10 is a compound semiconductor substrate, for example, and there is a GaAs substrate as an example. The resistivity of the GaAs substrate is 1.0 × 10 ⁵ Ω · cm or more. The upper limit of the resistivity of the GaAs substrate 10 is not particularly limited, but for example, it is 1.0 × 10 ⁹ Ω · cm or less. The shape of the substrate 10 in plan view (hereinafter referred to as a planar shape) is a rectangular shape. Examples of the rectangular shape include a quadrangular shape, a rectangular shape, a rounded square shape, and a rounded rectangular shape. The plan view is a top view.

(1.2) Magnetic Sensitive Section The magnetic sensitive section 20 is formed on the upper surface 10a of the substrate 10, and its shape in cross-sectional view (hereinafter, cross-sectional shape) is a mesa shape. Further, in the fifth embodiment of the present invention, the planar shape of the magnetic sensitive unit 20 is rectangular. In each embodiment of the present invention, the formation position of the magnetic sensitive part 20 is not limited to the upper surface 10 a of the substrate 10. A part or all of the magnetosensitive part (active layer) 20 may be formed inside the substrate 10 on the upper surface 10a side. The magnetic sensitive part 20 is preferably formed of GaAs from the viewpoint of temperature characteristics. However, the present embodiment is not limited to the configuration in which the magnetically sensitive portion 20 is formed using GaAs as a material, and for example, a compound semiconductor such as InSb or InAs can also be used.

The magnetic sensitive part 20 is a layer having a lower resistance than the substrate 10. For example, the magnetic sensing unit 20 may be formed by implanting impurities such as Si, Sn, S, Se, Te, Ge, or C into the substrate 10 and performing activation by heating, or by using a compound semiconductor containing the above impurities by MOCVD (Metal It is formed by growing it on the substrate 10 by an epitaxial growth method by an organic chemical vapor deposition (MBD) method, an MBE (molecular beam epitaxy) method, or the like.
For example, the magnetic sensitive part 20 has a conductive layer 21 and a surface layer 22 formed on the conductive layer 21. The conductive layer 21 is made of n-type GaAs formed on the substrate 10. The film thickness of the conductive layer 21 is not particularly limited, but is preferably 50 nm or more and 2000 nm or less, and more preferably 100 nm or more and 1000 nm or less from the viewpoint of ease of manufacture.

As the n-type impurity (that is, donor-type impurity) of n-type GaAs, a known one can be used, and for example, Si, Ge, Se, or the like can be used. The concentration of n-type impurities (effective carrier concentration) is not particularly limited, but the effective carrier concentration is 1.0 × 10 ¹⁴ [cm ⁻³ ] or more and 1.0 × 10 ¹⁹ from the viewpoint of the output and temperature characteristics of the Hall element. [Cm ⁻³ ] or less is preferable, and 1.0 × 10 ¹⁵ [cm ⁻³ ] or more and 1.0 × 10 ¹⁸ [cm ⁻³ ] or less is more preferable, and 1.0 × 10 ¹⁵ [cm ³ ] or less. More preferably, it is not less than cm ⁻³ ] and not more than 5.0 × 10 ¹⁷ [cm ⁻³ ]. If the effective carrier concentration is within the above range, it is preferable because the temperature dependency of the output is suppressed and the absolute value of the output can be easily obtained.
As a method for forming the conductive layer 21, there is a method in which an impurity is ion-implanted into the substrate 10 to form an n-type GaAs layer near or inside the surface of the substrate 10. As another method for forming the conductive layer 21, there is a method in which a GaAs thin film is epitaxially grown on the substrate 10 while doping impurity ions by MBE (molecular beam epitaxy) or MOCVD (metal organic chemical vapor deposition). Can be mentioned.

The surface layer 22 is a layer formed on the conductive layer 21 and made of a high-resistance crystal layer such as a GaAs layer having lower conductivity than the conductive layer 21 or an AlGaAs or AlAs layer. The film thickness of the surface layer 22 is 150 nm or more, preferably 200 nm or more in order to realize a Hall element in which variation in sheet resistance is suppressed, and from the viewpoint of manufacturability, preferably 800 nm or less. More preferably, it is 600 nm or less. Note that the surface layer may be omitted.
The method for forming the surface layer 22 is not particularly limited, and can be formed, for example, by ion implantation, or epitaxial growth using MBE or MOCVD. Examples of a method for obtaining GaAs having lower conductivity than the conductive layer 21 like the surface layer 22 include a method of setting an impurity concentration lower than that of the conductive layer 21 and a method of not intentionally doping impurities. Further, in order to directly ohmic-connect the conductive layer 21 and the first to fourth electrodes 31 to 34, a part of the surface layer 22 may be etched to be thinned or removed.

  FIG. 24 is a plan view illustrating a configuration example of the magnetic sensing unit 20. As shown in FIG. 24, the center position 25 of the rectangular magnetic sensing part 20 substantially coincides with the center position of the rectangular substrate 10 in plan view. Further, in plan view, the first to fourth sides 26 to 29 on the outer periphery of the magnetic sensing unit 20 are respectively parallel to two of the first to fourth sides 11 to 14 on the outer periphery of the substrate 10. ing. That is, in plan view, the first to fourth sides 26 to 29 on the outer periphery of the magnetic sensing unit 20 are parallel or perpendicular to the first to fourth sides 11 to 14 on the outer periphery of the substrate 10. More specifically, the first side 11 and the third side 13 on the outer periphery of the magnetic sensing unit 20 are parallel to the first side 26 and the third side 28 on the outer periphery of the substrate 10 and the first side 11 and the third side 28 on the outer periphery of the substrate 10. It is perpendicular to the second side 27 and the fourth side 29. The second side 12 and the fourth side 14 on the outer periphery of the magnetic sensing unit 20 are parallel to the second side 27 and the fourth side 29 on the outer periphery of the substrate 10 and the first side 26 and the outer side of the substrate 10. It is perpendicular to the third side 28.

In addition, the magnetic sensing unit 20 includes a central region 23 including the central position 25 of the magnetic sensing unit 20 in a plan view, and a peripheral region 24 positioned around the central region 23. In the present embodiment, the planar shape of the central region 23 is, for example, a perfect circle shape. The planar shape of the magnetic sensitive unit 20 is, for example, a square shape. In the case of this embodiment, when the diameter of the central region 23 is L1, and the length of one side of the outer periphery of the magnetic sensing unit 20 (that is, one side of the first to fourth sides 26 to 29) is L2, The ratio of L1 and L2 (L1 / L2) is, for example, not less than 1/4 and less than 1, or not less than 1/3 and not more than 1/2.
In the present embodiment, the planar shape of the central region 23 may be rectangular. When the central region 23 is rectangular, one side of the outer periphery of the rectangle corresponds to the above L1.

(1.3) Electrode FIG. 25 is a plan view illustrating a configuration example of the first to fourth electrodes 31 to 34. First, the positional relationship between the first to fourth electrodes 31 to 34 and the magnetic sensing unit 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 more than the outer perimeter 20e of the magnetic sensing unit 20 in plan view. Located inside. That is, the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 are inside the region surrounded by the outer periphery e of the magnetic sensing unit 20 in a plan view, and It is located in a region that does not overlap with the outer periphery e of the magnetic part 20.

  Here, the outer periphery of the magnetic sensing part 20 is the outermost contour line of the magnetic sensing part 20 in plan view. For example, as shown in FIG. 23A to FIG. 23C, when the cross-sectional shape of the magnetic sensing unit 20 is a mesa shape, the side surface ( Hereinafter, an upper end side contour line (hereinafter referred to as “mesa side surface”) 201 (hereinafter referred to as “mesa upper side contour line”) 202 and a lower end side contour line of mesa side surface 201 (hereinafter referred to as “mesa lower side contour line”). 203). The mesa upper contour line 202 is a boundary line between the upper surface 20 a of the magnetic sensing unit 20 and the mesa side surface 201. Further, the mesa lower contour line 203 is a boundary line between the mesa side surface 201 and the upper surface 10 a of the substrate 10. In each embodiment of the present invention, the mesa lower contour line 203 corresponds to the outer periphery of the magnetic sensing unit 20.

Therefore, in each embodiment of the present invention, even when the first to fourth electrodes 31 to 34 extend from the upper surface 20a of the magnetic sensing unit 20 to the mesa side surface 201, they extend to the mesa lower contour line 203. Not set up. The mesa lower outline 203 is exposed from below the first to fourth electrodes 31 to 34.
Moreover, in each embodiment of this invention, it is preferable that the 1st-4th electrodes 31-34 are provided only in the upper surface 20a side of the magnetic sensing part 20, and are not extended in the mesa side surface 201. FIG. That is, it is preferable that the mesa side surface 201 of the magnetic sensing unit 20 is exposed from below the first to fourth electrodes 31 to 34. Thereby, the wire bonding property mentioned later improves further.

Next, the shape and arrangement of the first to fourth electrodes 31 to 34 on the upper surface 20a side of the magnetic sensing unit 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 that intersects (for example, is orthogonal to) the first direction in plan view. The first to fourth electrodes 31 to 34 extend from the peripheral area 24 of the magnetic sensitive part 20 to the central area 23 on the upper surface side of the magnetic sensitive part 20.
That is, the first electrode 31 has a main part 31 a and an extending part 31 b extending from the main part 31 a to the central region 23 of the magnetic sensitive part 20. The second electrode 32 includes a main part 32 a and an extension part 32 b extending from the main part 32 a to the central region 23 of the magnetic sensitive part 20. The third electrode 33 has a main part 33 a and an extending part 33 b extending from the main part 33 a to the central region 23 of the magnetic sensitive part 20. The fourth electrode 34 has a main portion 34 a and an extending portion 34 b extending from the main portion 34 a to the central region 23 of the magnetic sensitive portion 20.

As shown in FIG. 25, the distance between the first electrode 31 and the second electrode 32 in the first direction (that is, the distance between the extending portions 31b and 32b) is D1, and the distance in the second direction is When the distance between the third electrode 33 and the fourth electrode 34 (that is, the distance between the extending portions 33b and 33c) is D2, D1 and D2 are 1 μm or more and 40 μm or less, respectively.
The shape and arrangement of the first to fourth electrodes 31 to 34 will be described more specifically with examples.
The planar shapes of the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 are each rectangular. In addition, the first corner 31 c included in the first electrode 31, the second corner 32 c included in the second electrode 32, the third corner 33 c included in the third electrode 33, and the fourth The fourth corner portion 34 c of the electrode 34 is positioned above the magnetic sensing portion 20.

Here, the first corner portion 31 c is a portion included in the extension portion 31 b of the first electrode 31. The second corner portion 32 c is a portion included in the extension portion 32 b of the second electrode 32. The third corner portion 33 c is a portion included in the extension portion 33 b of the third electrode 33. The fourth corner portion 34 c is a portion included in the extended portion 34 b 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 portion 31c and the second corner portion 32c face each other in the first direction, and the third corner portion 33c and the fourth corner portion 34c face each other in the second direction.
In plan view, 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 with the center position of the magnetic sensing unit 20. Yes. Further, in a plan view, the outer periphery of each of the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 is a region surrounded by the outer periphery of the magnetic sensing unit 20 (that is, the first electrode To a region surrounded by the fourth sides 26 to 29).

As shown in FIG. 22, the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 are respectively disposed at four rectangular corners of the substrate 10. The outer sides of each of the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 are parallel to two of the four sides of the outer periphery of the substrate 10. It has become. That is, each side of the outer periphery of the first to fourth electrodes 34 is parallel or perpendicular to the first to fourth sides 11 to 14 of the outer periphery of the substrate 10 in plan view.
As shown in FIG. 23, the first to fourth electrodes 31 to 34 are formed on the first metal film 131 and the first metal film 131 that are electrically connected to the magnetic sensing unit 20, respectively. Second metal film 132 formed. That is, the first metal film 131 serves as a contact region for the magnetic sensitive part 20.

An insulating film 40 is formed between the magnetic sensitive part 20 and the second metal film 132. The insulating film 40 is, for example, a silicon nitride film (Si ₃ N ₄ film), a silicon oxide film (SiO ₂ film), an inorganic film (Al ₂ O ₃ ), or a polyimide film, and is a multilayer film in which a plurality of these films are stacked. is there. That is, the insulating film 40 is disposed between the magnetic sensitive part 20 and the first to fourth electrodes in a cross-sectional view. The insulating film 40 has openings 401 at positions that overlap the four corners of the rectangular portion of the magnetic sensitive unit 20. In these openings 401, the magnetic sensitive unit 20 and the first to fourth electrodes 31 to 34 are in contact with each other. Note that the insulating film 40 may be formed on the first metal film 131 as illustrated in FIG. 23 or may not be formed on the first metal film 131, and may be formed under the first metal film 131. It may be formed in a part.

(1.4) Area where metal fine wires are joined (wire bonding area)
26 (a) to 26 (c) are schematic views showing wire bonding regions in the Hall element 500, FIG. 26 (a) is a plan view, and FIG. 26 (b) is a plan view of FIG. 26 is a cross-sectional view taken along line P′26, and FIG. 26C is a cross-sectional view taken along line Q26-Q′26 in FIG.
As shown in FIGS. 26A to 26C, the first electrode 31 has a first wire bonding region 141 to which a thin metal wire is bonded on the upper surface side. 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 magnetic sensitive part 20.

The second electrode 32 has a second wire bonding region 142 to which a fine metal wire is bonded on the upper surface side. 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 magnetic sensitive part 20.
The third electrode 33 has a third wire bonding region 143 to which a fine metal wire is bonded on the upper surface side. The first metal film 131 constituting the third electrode 33 becomes a contact region where the third electrode 33 is in contact with the magnetic sensitive part 20.
The fourth electrode 34 has a fourth wire bonding region 144 to which a fine metal wire is bonded on the upper surface side. The first metal film 131 constituting the fourth electrode 34 becomes a contact region where the fourth electrode 34 is in contact with the magnetic sensitive part 20.

That is, the contact regions of the first to fourth electrodes 31 to 34 are located outside the center positions of the first to fourth wire bonding regions 141 to 144 when viewed from the center position 25 of the magnetic sensing unit 20. Each is located.
In the cross-sectional view, the insulating film 40 is interposed between the first to fourth electrodes 31 to 34 and the magnetic sensitive part 20 in a region where the fine metal wires are joined (wire bonding region), and is in contact with the magnetic sensitive part 20. The region to be opened has an opening 401.
Moreover, in the area | region where a metal fine wire is joined, the magnetic sensing part 20 has a flat surface where the upper surface is flat. The insulating film 40 may be a stress relaxation insulating film.

  As described above, since the first electrode 31 and the second electrode 32 are the input electrodes of the Hall element 500, the Hall element is between the contact region of the first electrode 31 and the contact region of the second electrode 32. This becomes the signal input path 146 in 500. Further, since the third electrode 33 and the fourth electrode 34 are output electrodes of the Hall element 500, a signal between the contact region of the third electrode 33 and the contact region of the fourth electrode 34 is a signal in the Hall element 500. The output path 145 becomes.

(2) Hall sensor FIGS. 27A to 27D are a cross-sectional view, a plan view, a bottom view, and an external view showing a configuration example of the Hall sensor 700 according to the fifth embodiment of the present invention. FIG. 27A shows a cross section of FIG. 27B taken along the broken line R27-R′27. Further, in FIG. 27B, in order to avoid complication of the drawing, the mold member is omitted.
As shown in FIGS. 27A to 27D, the Hall sensor 700 includes a Hall element 500, a lead terminal 520, first to fourth metal thin wires (conductive connection members) 531 to 534, A protective layer 540, a mold member 550, and an exterior plating layer 560 are provided. Further, the lead terminal 520 has first to fourth terminal portions 521 to 524.
The hall sensor 700 has, for example, an islandless structure, and includes a plurality of terminal portions 521 to 524 for obtaining electrical connection with the outside. As shown in FIG. 27B, the first to fourth terminal portions 521 to 524 are arranged 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 holes. The elements 500 are disposed so as to face each other. Then, a straight line (virtual line) connecting the first terminal portion 521 and the second terminal portion 522 and a straight line (imaginary line) connecting the third terminal portion 523 and the fourth terminal portion 524 are seen in a plan view. Cross at. The lead terminal 520 (first to fourth terminal portions 521 to 524) is made of a metal such as copper (Cu), for example.
The first to fourth thin metal wires 531 to 534 are conductive wires that electrically connect the first to fourth electrodes 31 to 34 included in the Hall element 500 and the first to fourth terminal portions 521 to 524, respectively. For example, it is made of gold (Au). As shown in FIG. 27B, the first thin metal wire 531 connects the first terminal portion 521 and the first electrode 31. The second thin metal wire 532 connects the second terminal portion 522 and the second electrode 32. The third thin metal wire 533 connects the third terminal portion 523 and the third electrode 33. The fourth thin metal wire 534 connects the fourth terminal portion 524 and the fourth electrode 34. The 1st-4th metal fine wires 531-534 are joined in the wire bonding area | region of the 1st-4th electrodes 31-34 of a Hall element.

  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 a partial region on the upper surface of the first to fourth electrodes 31 to 34. Below the joining region where the first to fourth thin metal wires 531 to 534 (details will be described later) on the upper surfaces of the first to fourth electrodes 31 to 34 are joined, the first to fourth electrodes and the sensation are sensed. An insulating film 40 is interposed between the magnetic part 20. Here, the “joining region” is a region where the first to fourth thin metal wires 531 to 534 are actually in contact with the upper surfaces of the first to fourth electrodes 31 to 34, and the first to fourth It is not the ball diameter of the fine metal wires 531 to 534. For this reason, the junction area | region where the 1st-4th metal fine wires 531-534 join to the upper surface of the 1st-4th electrodes 31-34 exists in the 1st-4th wire bonding area | regions 141-144. As described above, the contact regions of the first to fourth electrodes 31 to 34 are more than the center positions of the first to fourth wire bonding regions 141 to 144 when viewed from the center position 25 of the magnetic sensing unit 20. Each is located outside. Therefore, the first to fourth electrodes 31 to 34 are 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, and the magnetic sensitive part. 20. The center of each contact region of the first to fourth electrodes 31 to 34 is preferably located outside the center of the first to fourth electrodes 31 to 34.

  Further, as described above, the first metal film 131 serves as a contact region for the magnetic sensitive portion 20. An opening 401 of the insulating film 40 is provided on the first metal film 131. For this reason, the opening 401 of the insulating film 40 is joined to the upper surfaces of the first to fourth electrodes 31 to 34 by the first to fourth thin metal wires 531 to 534 when viewed from the central position 25 of the magnetic sensing unit 20. It arrange | positions outside the joining area | region to do. That is, the insulating film 40 has the opening 401 located outside the bonding region in a top view. The first to fourth electrodes 31 to 34 are in contact with the magnetic sensing unit 20 at the opening 401. Therefore, the area | region where the 1st-4th electrodes 31-34 contact the magnetic sensing part 20 is arrange | positioned outside the area | region where the 1st-4th metal fine wires 531-534 are joined by planar view.

The protective layer 540 covers the surface 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 made of 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, an epoxy-based thermosetting resin and an insulating paste containing silica (SiO ₂ ) as a filler, silicon nitride, silicon dioxide, or the like can be considered. As the semiconductor, for example, bonding of a Si substrate or a Ge substrate can be considered. However, from the viewpoint of preventing leakage current, the protective layer 540 is preferably an insulator. The protective layer 540 may have a stacked structure.
The mold member 550 molds the Hall element 500, the first to fourth terminal portions 521 to 524, and the first to fourth metal thin wires 531 to 534. In other words, the mold member 550 includes the Hall element 500, at least the surface side of the first to fourth terminal portions 521 to 524 (that is, the surface connected to the metal thin wire), and the first to fourth metals. The thin wires 531 to 534 are covered and protected (that is, resin-sealed). The mold member 550 is made of, for example, an epoxy thermosetting resin and can withstand high heat during reflow.

As shown in FIGS. 27A and 27C, the first to fourth terminal portions 521 to 524 are arranged on the bottom surface side of the Hall sensor 700 (that is, on the side mounted on the wiring board magnetic sensing portion 20). At least a part of the first surface (for example, the back surface) and at least a part of the first surface (for example, the back surface) of the GaAs substrate 10 are exposed from the same surface (for example, the back surface) of the mold member 550, respectively. Yes. Here, the 1st surface of the 1st-4th terminal parts 521-524 is the 1st-4th metal thin wire 531-among the several surfaces which the 1st-4th terminal parts 521-524 have, respectively. This is the surface opposite to the surface connected to 534. 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 exterior plating layer 560 is formed on the back surface of the terminal portions 521 to 524 exposed from the mold member 550. The exterior plating layer 560 is made of, for example, tin (Sn).

[Operation]
In the case of detecting magnetism (magnetic field) using the Hall sensor 700 described above, for example, the first terminal portion 521 is connected to the power supply potential (+) and the second terminal portion 522 is set to the ground potential (GND). By connecting, current flows from the first terminal portion 521 to the second terminal portion 522. Then, a 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 / negative of the Hall output voltage VH.
That is, the first terminal portion 521 is a power supply terminal portion that supplies a predetermined voltage to the Hall element 500. The second terminal portion 522 is a ground terminal portion that supplies a ground potential to the Hall element 500. The third terminal portion 523 and the fourth terminal portion 524 are signal extraction terminal portions that extract the Hall electromotive force signal of the Hall element 500.

〔Production method〕
(1) Method for Manufacturing Hall Element FIGS. 28A to 28E are cross-sectional views showing a method for manufacturing the Hall element 500 in the order of steps. As shown in FIG. 28A, first, a substrate 10 is prepared. The substrate 10 is, for example, a GaAs substrate 10. Next, donor-type impurities are 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. 28B, a conductive layer 21 having a lower 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. Since the surface layer 22 has a lower impurity concentration than the conductive layer 21, it becomes a layer having a higher resistance than the conductive layer 21 (that is, a layer having low conductivity).

  Note that the step of activating the impurities may be performed after the patterning step of the substrate 10 shown in FIG. Moreover, you may perform by combining with the other heating process after the process shown in FIG.28 (c). The formation of the conductive layer 21 is not limited to ion implantation. For example, the conductive layer 21 may be formed by epitaxially growing GaAs containing impurities at a high concentration on the substrate 10 by MOCVD. In this case, following the formation of the conductive layer 21, GaAs containing impurities at a low concentration (or not containing impurities) is epitaxially grown to form a surface layer having a higher resistance than the conductive layer 21 on the conductive layer 21. 22 can be formed.

Next, the substrate 10 is patterned by using a photolithography technique and an etching technique to form the magnetically sensitive portion 20 having a mesa shape in cross-sectional view as shown in FIG.
Next, as shown in FIG. 28D, a first metal film 131 is partially formed on the substrate 10 on which the magnetic sensitive portion 20 is formed. Here, for example, an AuGe film, an Ni film, and an Au film are stacked in this order as the first metal film 131. The first metal film 131 is formed by, for example, lift-off or mask vapor deposition. Lift-off is a method in which a metal film is deposited on a substrate on which a resist pattern is formed, and then the resist pattern is removed, so that the metal film is left only on a region not covered with the resist pattern on the substrate. Mask vapor deposition is a method of depositing a metal film only on a region immediately below the through hole of the substrate by depositing a metal film on the substrate through a plate in which the through hole is partially formed. 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 illustrated in FIG. 28E, the insulating film 40 is formed on the portion of the substrate 10 that is exposed from below the first metal film 131. The insulating film 40 is, for example, a silicon nitride film. The insulating film 40 is formed by forming an insulating film on the entire upper surface of the substrate 10 by, for example, a CVD (Chemical Vapor Deposition) method, and then using the photolithography technique and the etching technique to form the insulating film formed on the entire upper surface. It is formed by patterning. Note that the first metal film 131 may be formed after an insulating film is formed on the entire top surface of the substrate 10 and patterned to form the insulating film 40.

Next, as shown in FIG. 28E, a second metal film 132 is partially formed on the substrate 10 on which the insulating film 40 is formed. Here, for example, a Ti film and an Au film are stacked in this order as the second metal film 132. Further, the second metal film 132 is formed by, for example, lift-off or mask vapor deposition.
Thereafter, a protective film (not shown) or the like is formed on the substrate 10. Then, the substrate 10 is diced, and the substrate 10 is separated into pieces for each of the plurality of Hall elements 500. Through the above steps, the Hall element 500 shown in FIG. 22 and the like is completed.

(2) Manufacturing Method of Hall Sensor FIGS. 29A to 29E and FIGS. 30A to 30D are plan views and cross-sectional views showing the manufacturing method of the Hall sensor 700 in the order of steps. is there. In FIG. 29A to FIG. 29E, the dicing blade width (ie, the kerf width) is not shown.
As shown in FIG. 29A, first, a lead frame 620 is prepared. The lead frame 620 is a substrate in which a plurality of lead terminals 520 shown in FIG. 27B are connected in the vertical direction and the horizontal direction in plan view.

  Next, for example, one surface of the heat-resistant film 580 is attached as a base material to the back surface side of the lead frame 620 as shown in FIG. For example, an insulating adhesive layer is applied to one surface of the heat resistant film 580. The adhesive layer is based on, for example, silicon resin as its component. This adhesive layer makes it easy to attach the lead frame 620 to the heat resistant film 580. By sticking the heat resistant film 580 to the back surface side of the lead frame 620, the penetration region through which the lead frame 620 penetrates is closed with the heat resistant film 580 from the back surface side.

Next, as shown in FIG. 29 (c), a hole having a protective layer 540 in a region surrounded by the first to fourth terminal portions 521 to 524 in the surface having the adhesive layer of the heat resistant film 580. The element 500 is placed (that is, die bonding is performed). Here, die bonding is performed with the first surface of the substrate 10 facing the surface having the adhesive layer of the heat resistant film 580.
Next, as shown in FIG. 29 (d), one ends of the first to fourth metal thin wires 531 to 534 are connected to the first to fourth terminal portions 521 to 524, respectively, and the first to fourth metals are connected. The other ends of the thin wires 531 to 534 are respectively connected to the first to fourth electrodes 31 to 34 of the Hall element 500 (that is, wire bonding is performed). The other ends of the first to fourth metal thin wires 531 to 534 are joined in the wire bonding regions of the first to fourth electrodes 31 to 34 of the Hall element 500.

The wire bonding may be forward bonding performed by extending a thin metal wire from each electrode of the Hall element 500 toward each terminal portion of the lead terminal 520, and conversely, from each terminal portion of the lead terminal 520 to the Hall element 500. Reverse bonding may be performed by extending a thin metal wire to each electrode. Inverse bonding can reduce the height of the loop of the Hall element because the loop height after bonding of the fine metal wires can be made lower than that of forward bonding.
Then, as shown in FIG. 29E, a mold member 550 is formed (that is, resin molding is performed). This resin mold is performed using, for example, a transfer mold technique.

  For example, as shown in FIG. 30A, a mold die 590 including a lower die 591 and an upper die 592 is prepared, and a lead frame 620 after wire bonding is disposed in the cavity of the mold die 590. . Next, the mold member 550 heated and melted is injected into the cavity and the side of the heat-resistant film 580 having the adhesive layer (that is, the surface bonded to the lead frame 620) and filled. Thus, the Hall element 500, the lead frame 620, and the fine 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 metal thin wires 531 to 534 are covered and protected by the mold member 550. When the mold member 550 is further heated and cured, the mold member 550 is removed from the mold.

Next, as shown in FIG. 30B, the heat resistant film 580 is peeled from the mold member 550. As a result, the substrate 10 of the Hall element 500 is exposed from the mold member 550. Then, as shown in FIG. 30C, exterior plating is applied to the surface exposed from the mold member 550 of the lead frame 620 (at least the back surface exposed from the mold member 550 of each terminal portion 521 to 524). Then, the exterior plating layer 560 is formed.
Next, as shown in FIG. 30 (d), a dicing tape 593 is attached to the upper surface of the mold member 550 (that is, the surface opposite to the surface having the exterior plating layer 560 of the Hall sensor 700). Then, for example, along the virtual two-dot chain line shown in FIG. 29E, the blade is moved relative to the lead frame 620 to cut the mold member 550 and the lead frame 620 (that is, dicing is performed). Do.) That is, the mold member 550 and the lead frame 620 are diced for each of the plurality of Hall elements 500 to be singulated. Through the above steps, the Hall sensor 700 shown in FIG. 27 is completed.

[Effect of Fifth Embodiment]
The fifth embodiment of the present invention has the following effects.
(1) The magnetic sensing unit 20 is not only between the electrodes (that is, between the first electrode 31 and the second electrode 32 and between the third electrode 33 and the fourth electrode 34), It is also formed immediately below each of the first to fourth electrodes 31 to 34. Therefore, the space on the substrate 10 can be used more effectively than in the case where the magnetosensitive portion is formed only between the electrodes, and the Hall element can be downsized and the S / N (Signal to Noise ratio) can be reduced. Both improvements can be realized.

(2) Further, the mesa side surface 201 of the magnetic sensing unit 20 is formed to be outside the outer peripheries 31e to 34e of the first to fourth electrodes 31 to 34. For this reason, the wire bonding property in a packaging process improves, and the improvement of a yield and conduction | electrical_connection defect can be improved. Thereby, a decrease in the reliability of the Hall sensor can be suppressed. It is also possible to improve the reliability of the Hall sensor.
Specifically, the mesa side surface 201 of the magnetic sensing unit 20 formed on the upper surface 10 a of the substrate 10 is inclined or has a step from the upper surface 20 a of the magnetic sensing unit 20 to the upper surface 10 a side of the substrate 10. The 1st-4th electrodes 31-34 with which Hall element 500 is provided, and the 1st-4th terminal parts 521-524 with which lead terminal 520 is provided are connected with the 1st-4th metal thin wires 531-534, respectively. In the wire bonding step, spherical balls are formed by spark discharge at one ends of the first to fourth metal thin wires 531 to 534, respectively, and the balls are pressed against the first to fourth electrodes 31 to 34, respectively. Or, it is joined by vibrating each with ultrasonic waves.

Here, when the slope structure or the step structure which is the mesa side surface of the magnetic sensing part is under the electrode, the wire bonding property is deteriorated in the wire bonding process. This causes a decrease in the yield of the wire bonding process and poor conduction between the Hall element and the terminal portion.
On the other hand, according to the fifth embodiment of the present invention, the slope structure or the step structure which is the mesa side surface 201 of the magnetic sensing unit 20 is outside the outer periphery of the first to fourth electrodes 31 to 34. Is formed. That is, the first to fourth electrodes 31 to 34 are formed on the flat upper surface 20 a of the magnetic sensing unit 20. As a result, the first to fourth electrodes 31 to 34 are also formed flat.
For this reason, the ball | bowl formed in the end of the 1st-4th thin metal wires 531-534 in the case of wire bonding will be pressed on the flat 1st-4th electrodes 31-34. Therefore, wire bondability is improved, yield can be improved, and conduction failure can be improved. Even if the insulating film 40 such as Si ₃ N ₄ is formed between the first to fourth electrodes 31 to 34 and the magnetic sensing unit 20, the magnetic sensing is performed below the first to fourth electrodes 31 to 34. Since there is no mesa side surface 201 of the part 20, the wire bonding property is good.

(3) Further, when viewed from the center position of the magnetic sensing portion 20, the contact regions of the first to fourth electrodes 31 to 34 (that is, the positions where the first metal film 131 is formed) are the first to fourth. It is located outside the center of the wire bonding regions 141 to 144, respectively. As a result, the distance between the signal output path 145 and the signal input path 146 can be increased without increasing the chip area of the Hall element as compared with the case where the contact area is present immediately below the wire bonding area. This can contribute to improvement of the magnetic detection accuracy of the element.
In particular, in the Hall element 500, the planar shape of the magnetic sensing unit 20 is rectangular, and the contact regions of the first to fourth electrodes 31 to 34 are respectively arranged at the corners of the magnetic sensing unit 20. As a result, the signal output path 145 and the signal input path 146 can be maximized within a limited chip area, which can greatly contribute to the improvement of the magnetic detection accuracy.

  That is, after the insulating film 40 is formed on the magnetically sensitive portion 20 having a rectangular planar shape, holes are respectively provided at four positions overlapping the diagonal of the magnetically sensitive portion 20 of the insulating film 40. And the 1st-4th electrodes 31-34 are electrically connected to the magnetic sensing part 20 through these four holes. Thereby, a current can flow from one end to the other end on the diagonal line of the magnetic sensing unit 20. Thereby, since the region under the first to fourth electrodes 31 to 34 can also contribute to the Hall electromotive force, there is an effect of improving the S / N of the Hall element.

(4) In a thin Hall sensor, since the thickness of the mold member on the Hall element is thin, an electromagnetic wave including light incident on the magnetic sensing part of the Hall element photoelectrically converts the local conductivity of the magnetic sensing part. Fluctuate depending on the effect. Also, this variation causes an offset voltage Vu in the Hall element.
On the other hand, according to the fifth embodiment, the first to fourth electrodes 31 to 34 extend from the peripheral region 24 of the magnetic sensitive unit 20 to the central region 23 in plan view, and A part 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 the four corners of the rectangular substrate 10 to the central region 23 of the magnetic sensitive unit 20. And in this center area | region 23, each extension part 31b-34b of the 1st-4th electrodes 31-34 is each arrange | positioned closely, and the clearance gap between adjacent electrodes is narrow. Accordingly, a part of the central region 23 of the magnetic sensitive unit 20 is covered with the first to fourth electrodes 31 to 34.

Here, the metal which is an electrode member absorbs electromagnetic waves including light very well. Therefore, the first to fourth electrodes 31 to 34 can shield the electromagnetic wave incident on the magnetic sensing part 20 of the Hall element 500 and can suppress local conductivity fluctuations in the magnetic sensing part 20. This has the effect of suppressing fluctuations in the offset voltage Vu.
In particular, when the ratio of the total area on the central region of the first to fourth electrodes 31 to 34 to the area of the central region of the magnetic sensing unit 20 in a plan view is 10% or more and less than 100%, the offset voltage Vu. Highly effective in suppressing fluctuations. Preferably, they are 20% or more and 99% or less, More preferably, they are 40% or more and 95% or less.

(5) Further, a local stress is applied to the magnetically sensitive portion by a filler or the like in the mold member constituting the package. In response to the stress, local fluctuations in conductivity occur due to the piezoresistive effect of the semiconductor that is the magnetically sensitive material. As a result, an offset voltage Vu is generated in the Hall element.
On the other hand, according to the fifth embodiment, the metal that is the electrode member is plastically deformed flexibly by the stress. Therefore, the local stress from the mold member 550 is alleviated, and the local conductivity in the magnetic sensitive portion 20 is reduced. Variations can be suppressed. This has the effect of suppressing fluctuations in the offset voltage Vu of the Hall element.

(6) The heat generated in the magnetic sensing unit 20 is generated from the magnetic sensing unit 20 by the first to fourth electrodes 31 to 34, the first to fourth metal wires 531 to 534, and the first to fourth terminals. Heat is discharged out of the package through the parts 521 to 524. Since the magnetic sensitive part 20 is covered with the first to fourth electrodes 31 to 34 made of metal having high conductivity, the insulating film 40, the first to fourth electrodes 31 to 34, and the first one are provided from the magnetic sensitive part 20. -The waste heat path through the 4th metal fine wires 531-534 newly increases. This has the effect of improving the exhaust heat characteristics of the Hall element.

(7) In addition, the semiconductor device includes an insulating film 40 disposed between the magnetically sensitive portion 20 and the first to fourth electrodes 31 to 34 in a cross-sectional view, and the insulating film 40 includes the first to first electrodes in a cross-sectional view In the region where the four fine metal wires 531 to 534 are joined, the insulating film 40 is interposed between the first to fourth electrodes 31 to 34 and the magnetic sensitive portion 20, and in the region where the magnetic sensitive portion 20 is contacted, an opening portion is provided. By having 401, when joining the first to fourth thin metal wires 531 to 534, the region under which the first to fourth fine metal wires 531 to 534 are joined is interposed via the insulating film 40. Since it becomes the upper surface of the flat magnetic sensing part 20, wire bonding property further improves.

<Sixth Embodiment>
In the fifth embodiment, each of the first electrode 31, the second electrode 32, the third electrode 33, and the fourth electrode 34 is arranged from the peripheral region 24 to the central region of the magnetic sensing unit 20 in plan view. The case of extending to 23 has been described. However, the present invention is not limited to this.
FIG. 31 is a plan view showing a configuration example of the Hall element 600 according to the 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 the peripheral regions of the magnetic sensing unit 20. 24 is formed only. 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 in 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 of the fourth electrode 34 in plan view. 34 e is located inside the outer periphery 20 e of the magnetic sensing unit 20. Therefore, the sixth embodiment has the same effects as the effects (1) to (7) of the fifth embodiment.

<Seventh embodiment>
In the fifth embodiment, the center region 23 of the magnetic sensing unit 20 is defined by L1 and L2 with reference to FIG. Also 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 an inner region of a circle indicated by a broken line, for example. More specifically, as shown in FIG. 32, in a plan view, it is a circle having the same center as the geometric center of gravity of the magnetic sensing unit 20 (illustrated by + mark), and the minimum distance from the center of gravity to the contact region is An auxiliary circle 30 is defined as a radius. The central region 23 is an inner region of a circle having a diameter of ½ with respect to the auxiliary circle 30 and centering on the center of gravity. The geometric center of gravity of the magnetic sensing unit 20 can be obtained from a figure surrounded by the boundary between the magnetic sensing unit 20 and the substrate 10 in plan view. The contact region is a portion where the first to fourth electrodes 31 to 34 and the magnetic sensing portion 20 are connected to each other.

The central region (for example, the inner region of a circle indicated by a broken line) 23 is a main region that contributes to the Hall effect, particularly in the magnetic sensitive portion 20. Further, the outside of the central region 23 is set as a peripheral region 24. Note that the planar shape of the central region 23 is not limited to a circular shape. The planar shape of the central region 23 may be rectangular.
As described above, even when the central region 23 is defined using the auxiliary circle 30, the same effects as the effects (1) to (7) of the fifth embodiment are achieved.
In FIG. 32, the central region 23 is defined using the auxiliary circle 30 for the Hall element 500 described in the fifth embodiment, but the auxiliary circle is also used for the Hall element 600 described in the sixth embodiment. The central region 23 can be defined in the same manner as described above.

<Example of configuration of hall sensor with hall element>
Hereinafter, the first to fourth electrodes 31 to 34 and the first to fourth electrodes in the Hall sensor 700 (see FIGS. 7 and 27) including any of the Hall elements according to the first to seventh embodiments described above. The positional relationship between the contact regions 31 to 34 and the first to fourth wire bonding regions 141 to 144 will be described in detail with reference to FIGS. 33 and 34.
33 and 34, as an example, the formation position of the first metal film 131 that is the contact region of the first electrode 31 will be described. The formation positions of the contact regions described below are the second to fourth positions. The same applies to the electrodes 32-34. 33 and 34, the first electrode 31 and the magnetic sensing part 20 are described as having a rectangular shape (square shape). However, the shapes of the first electrode 31 and the magnetic sensing part 20 are the same. The shape described in each embodiment described above may be used. Similarly, the shape of the contact region is not limited to the shape described in FIGS. 33 and 34, and may be the shape described in each of the above-described embodiments.

  First, a first example and a second example of the contact region formation position will be described. The first example and the second example will be described with reference to FIG. 33 in the case where the junction region F extends outside the center O2 of the first electrode 31 when viewed from the center of the magnetic sensing unit 20. .

(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 indicate the positions of suitable contact regions. Among these, the first metal films 131a and 131b indicate positions of contact regions that are more preferable as the first example, and the first metal film 131a indicates positions of contact regions that are more preferable as the first example. ing. On the other hand, the first metal films 131b, 131c, and 131d indicate positions of contact regions that are not suitable as the second example.

In each Hall sensor 700 according to each of the above-described embodiments, the region (contact region) where the first electrode 31 contacts the magnetic sensing unit 20 is the first thin metal wire 531 when viewed from the central position 25 of the magnetic sensing unit 20. (Refer to FIG. 7) is located outside the center O1 of the joining region F to be joined. That is, the first metal film 131 a, 131 b, or 131 c is provided as the first metal film 131. As a result, the contact region is located outside the center O1 of the bonding region F when viewed from the center position 25 of the magnetic sensing unit 20.
Therefore, fluctuations in the offset voltage of the Hall element provided in the Hall sensor 700 can be suppressed.

This is because the contact region is arranged outside the center O1 of the junction region F, so that a main region (for example, the central region 23 shown in FIG. 4) contributing to the Hall effect is widened within a limited chip area. Because it can. By enlarging the main region that contributes to the Hall effect, the influence of resistance variation per unit area can be reduced, and variation in offset voltage can be suppressed.
Further, the variation of the offset voltage of the Hall element is sensitive to local resistance variation of the contact region, and the junction region F generates stress under the stress, and due to the piezoresistance effect on the semiconductor as the magnetically sensitive material. Resistance variation occurs. In particular, the stress generated is large below the center O1 of the bonding region F. For this reason, by positioning the contact region on the outer side from the center O1 of the junction region F, the stress acting on the contact region can be reduced, and the fluctuation of the offset voltage can be suppressed.

The center of the region (contact region) where the first electrode 31 is in contact with the magnetic sensing unit 20 is located outside the center O2 of the first electrode 31, and the region where the first thin metal wire 531 is joined. The center O <b> 1 is preferably located inside the center O <b> 2 of the first electrode 31. That is, it is preferable to provide the first metal film 131 a or 131 b as the first metal film 131. As a result, the contact region is located outside the center O1 of the junction region F when viewed from the center position 25 of the magnetic sensing portion 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.

Furthermore, it is more preferable that a region (contact region) in which the first electrode 31 is in contact with the magnetic sensitive part 20 is disposed outside the bonding region F to which the first metal thin wire 531 is bonded in a plan view. That is, it is more preferable to provide the first metal film 131 a as the first metal film 131. As a result, the contact region is located outside the center O1 of the junction region F when viewed from the center position 25 of the magnetic sensing portion 20, and the center of the contact region is located outside the center O2 of the first electrode 31. The contact region is disposed outside the junction region F in plan view.
Therefore, a contact region can be formed outside the junction region F where the generated stress is large, and fluctuations 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 indicate the positions of suitable contact regions. Among these, the first metal film 131a shows a more preferable position of the contact region as the second example. On the other hand, the first metal films 131b, 131c, and 131d indicate positions of contact regions that are not favorable as a second example.

In each Hall sensor 700 according to each of the above-described embodiments, the first electrode 31 is connected to the magnetic sensing unit 20 outside the bonding region F where the metal thin wire 531 is bonded. The insulating film 40 has the opening 401 located outside the bonding region F in a top view, so that the first electrode 31 is in contact with the magnetic sensing unit 20 through the opening 401. That is, the first metal film 131 a or 131 e is provided as the first metal film 131. As a result, the first metal film 131a or 131e is connected to the magnetic sensing part 20 outside the bonding region F.
Therefore, the contact region can be formed outside the junction region F where the generated stress is large, and fluctuations in the offset voltage of the Hall element can be suppressed. In addition, the wire bonding property is improved, and the reliability of the Hall sensor 700 is improved. This is because the adhesiveness of the bonding portion is improved by forming the bonding region F in the flat electrode portion while avoiding the step of the opening 40.

In addition, when viewed from the center position 25 of the magnetic sensitive portion 20, the opening 401 (see FIGS. 2, 23, etc.) of the insulating film 40 is disposed outside the joining region F to which the fine metal wires 531 are joined. Is preferred. That is, it is preferable to provide the first metal film 131 a as the first metal film 131. Thereby, the first metal film 131a is connected to the magnetic sensing part 20 outside the bonding area F, and the opening 401 of the insulating film 40 is located outside the bonding area F when viewed from the central position 25 of the magnetic sensing part 20. Is placed.
Therefore, the main region contributing to the Hall effect can be enlarged, the influence of resistance fluctuation per unit area can be reduced, and fluctuations in offset voltage can be further suppressed.

  Next, a third example and a fourth example of the contact region formation position will be described. In the third example and the fourth example, the case where the bonding region F is formed on the inner side of the center O2 of the first electrode 31 when viewed from the center of the magnetic sensitive part 20 will be described with reference to FIG. To do. In addition, about the effect of each structure, since it is the same as that of the 1st example and the 2nd example, description is abbreviate | 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 illustrated in FIG. 34 indicate suitable contact region positions. In particular, the first metal film 131A shows a more preferable position of the contact region as the first example. On the other hand, the first metal film 131D indicates the position of a contact region that is not a good enemy as a third example.

  In each Hall sensor 700 according to each of the above-described embodiments, the region (contact region) where the first electrode 31 contacts the magnetic sensing unit 20 is the first thin metal wire 531 when viewed from the center position 25 of the magnetic sensing unit 20. (Refer to FIG. 7) is located outside the center O1 of the joining region F to be joined. That is, the first metal film 131A, 131B, or 131C is provided as the first metal film 131. As a result, the contact region is located outside the center O1 of the bonding region F when viewed from the center position 25 of the magnetic sensing unit 20.

  The center of the region (contact region) where the first electrode 31 is in contact with the magnetic sensing unit 20 is located outside the center O2 of the first electrode 31, and the region where the first metal wire 531 is joined. The center O <b> 1 is preferably located inside the center O <b> 2 of the first electrode 31. That is, it is preferable to provide the first metal film 131 </ b> A as the first metal film 131. As a result, the contact region is located outside the center O1 of the junction region F when viewed from the center position 25 of the magnetic sensing portion 20, and the center of the contact region is located outside the center O2 of the first electrode 31. .

Moreover, it is preferable that the area | region (contact area | region) where the 1st electrode 31 contacts the magnetic sensing part 20 is arrange | positioned out of the joining area | region F where the 1st metal fine wire 531 is joined by planar view. That is, it is preferable to provide the first metal film 131 </ b> A or 131 </ b> B as the first metal film 131. As a result, the contact region is located outside the center O1 of the bonding region F when viewed from the center position 25 of the magnetic sensing unit 20, and the contact region is disposed outside the bonding region F in plan view.
Furthermore, it is more preferable to provide the first metal film 131 </ b> A as the first metal film 131. As a result, the contact region is located outside the center O1 of the junction region F when viewed from the center position 25 of the magnetic sensing portion 20, and the center of the contact region is located outside the center O2 of the first electrode 31. In addition, the contact region is disposed outside the junction region F in plan view.

  Further, in each Hall sensor 700 according to each of the above-described embodiments, the first electrode 31 is connected to the magnetic sensing unit 20 outside the bonding region F where the metal thin wire 531 is bonded. That is, the first metal film 131A, 131B, or 131D is provided as the first metal film 131. As a result, the first metal film 131A, 131B or 131D is connected to the magnetic sensitive part 20 outside the bonding region F.

  In addition, when viewed from the center position 25 of the magnetic sensitive portion 20, the opening 401 (see FIGS. 2, 23, etc.) of the insulating film 40 is disposed outside the joining region F to which the fine metal wires 531 are joined. Is preferred. That is, it is preferable to provide the first metal film 131 </ b> A or 131 </ b> B as the first metal film 131. Thereby, the first metal film 131A or 131B is connected to the magnetic sensing part 20 outside the bonding area F, and the opening of the insulating film 40 is located outside the bonding area F when viewed from the central position 25 of the magnetic sensing part 20. Unit 401 is arranged.

<Lens module>
Hereinafter, a lens module using the Hall sensor 700 according to the first to seventh embodiments will be described. FIG. 35A shows a lens module 8a for camera shake correction, and FIG. 35B shows a lens module 8b for autofocus.
As shown in FIGS. 35A and 35B, each of the lens modules 8a and 8b includes one of the Hall sensors 700 according to the first to seventh embodiments, a lens holder 81 to which a magnet 80 is attached, And a drive coil 82 that moves the magnet based on a Hall electromotive force signal that is an output signal from an external terminal of the Hall sensor 700. Since the Hall sensor 700 according to the first to seventh embodiments can reduce the thickness of the mold member, the Hall sensor 700 itself can be reduced in thickness, and offset variation can be suppressed, so that magnetism can be accurately detected. Therefore, the lens modules 8a and 8b of this embodiment using any one of the Hall sensors 700 according to the first to seventh embodiments can be reduced in size and can be accurately detected. It becomes. In the lens modules 8a and 8b of the present embodiment, the magnetic field of the magnet 80 attached to the lens holder 81 is detected by the Hall sensor 700, and a driving current is supplied to the driving coil 82 based on an output signal corresponding to the detected magnetic field. Shed. Thereby, the lens module 8a can perform camera shake correction control with high accuracy, and the lens module 8b can perform auto focus control with high accuracy. In addition, since the lens modules 8a and 8b of the present embodiment are reduced in thickness, it is possible to bring the Hall element (not shown) inside the Hall sensor 700 closer to the magnet 80, and more accurate. High magnetic detection is possible.

<Other aspects>
The technical idea of the present invention is not limited to each embodiment and each example described above. Based on the knowledge of those skilled in the art, each embodiment and each example of the present invention may be modified in design, etc., and each embodiment and each example of the present invention may be arbitrarily combined. A mode in which such changes are added is also included in the technical idea of the present invention.

8a, 8b Lens module 10 Substrate 10a Upper surface 20 Magnetosensitive part 20e Periphery 21 (of magnetic sensor part) Conductive layer 22 Surface layer 23 Central area 24 Peripheral area 25 Center position 29 Auxiliary circle 31 First electrode 31a Main portion 31b (first electrode) extension portion 31c first corner portion 32 second electrode 32a (second electrode) main portion 32b (second electrode) extension portion 32c second Corner 33 third electrode 33a (third electrode) main portion 33b (third electrode) extension 33c third corner 34 fourth electrode 34a (fourth electrode) main portion 34b Extension portion 34c (fourth electrode) Fourth corner portion 40 Insulating film 80 Magnet 81 Lens holder 82 Drive coil 100, 200, 300, 400, 500, 600 Hall element 120 Main magnetic sensing portion 121 First Extension part 122 Second extension part 123 4th extending portion 126 1st diagonal line 127 2nd diagonal line 131 1st metal film 132 2nd metal film 141 1st wire bonding area 142 2nd wire bonding area 143 3rd Wire bonding area 144 Fourth wire bonding area 145 Signal output path 146 Signal input path 201 Mesa side surface 202 Mesa upper contour line 203 Mesa lower contour line 220 Central portion 221 First peripheral portion 222 Second peripheral portion 223 First 3 peripheral part 224 4th peripheral part 401 opening 520 lead terminal 521 1st terminal part 522 2nd terminal part 523 3rd terminal part 524 4th terminal part 531 1st metal wire 532 2nd Metal thin wire 533 Third metal thin wire 534 Fourth metal thin wire 540 Protective layer 550 Mold member 560 Exterior plating layer 580 Heat-resistant film 590 Mold die 591 Lower die 592 Upper die 593 Dicing tape 620 Lead frame 700 Hall sensor

Claims (9)

A substrate,
A magnetic sensitive part formed on one side of the substrate;
A first electrode and a second electrode which are formed on the one surface side and are electrically connected to the magnetic sensing portion and face each other in a first direction;
A third electrode and a fourth electrode which are formed on the one surface side and are electrically connected to the magnetic sensing part and face each other in a second direction intersecting the first direction in plan view;
An insulating film disposed between the magnetically sensitive portion and the first to fourth electrodes in a cross-sectional view,
Each of the insulating films has openings at positions overlapping with the four corners of the rectangular portion of the magnetic sensitive part,
The magnetic sensitive part and the first to fourth electrodes are in contact with each other at the opening,
The first electrode, the second electrode, the third electrode, and the fourth electrode extend from a peripheral region of the magnetic sensing portion to a central region of the magnetic sensing portion, respectively.
The Hall element whose minimum distance between the adjacent electrodes of the first to fourth electrodes is 2 μm or more and less than 8 μm in plan view. The Hall element according to claim 1, wherein a minimum distance between adjacent electrodes of the first to fourth electrodes is 4 μm or more. The shapes of the first electrode, the second electrode, the third electrode, and the fourth electrode in plan view are each rectangular,
A first corner of the first electrode; a second corner of the second electrode; a third corner of the third electrode; and a fourth corner of the fourth electrode. 4 corners are respectively located above the magnetic sensing part,
The first corner and the second corner face each other in the first direction, and the third corner and the fourth corner face each other in the second direction. Hall device according to 1 or claim 2. In plan view, a central portion of a region surrounded by the first corner portion, the second corner portion, the third corner portion, and the fourth corner portion overlaps with a central portion of the magnetic sensing portion. The Hall element according to claim 3 . The shape of the substrate in plan view is a rectangle,
The first electrode, the second electrode, the third electrode, and the fourth electrode are respectively disposed at four rectangular corners of the substrate,
The outer sides of each of the first electrode, the second electrode, the third electrode, and the fourth electrode are parallel to two of the four sides of the outer periphery of the substrate, respectively. The Hall element according to claim 3 or 4 . The hall element according to any one of claims 1 to 5 ,
A first terminal portion;
A second terminal portion;
A third terminal portion;
A fourth terminal portion;
A first thin metal wire connecting the first electrode and the first terminal portion;
A second fine 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 thin metal wire connecting the fourth electrode and the fourth terminal portion,
Each of the first to fourth electrodes has a region where the first to fourth fine metal wires are joined, and a region where the first to fourth electrodes are in contact with the magnetic sensing portion. And
The region where the first to fourth electrodes are in contact with the magnetic sensing portion is located outside the center of the joining region where the first to fourth metal fine wires are joined as seen from the center of the magnetic sensing portion. Hall sensor. The center of the region where the first to fourth electrodes are in contact with the magnetic sensing part is located outside the center of the first to fourth electrodes,
The hall sensor according to claim 6 , wherein a center of a region to which the thin metal wire is joined is located inside a center of the first to fourth electrodes. The hole according to claim 6 or 7 , wherein a region in which the first to fourth electrodes are in contact with the magnetically sensitive portion is disposed outside a joining region where the thin metal wires are joined in a plan view. Sensor. A hall sensor according to any one of claims 6 to 8 ,
A lens holder with a magnet attached thereto;
A lens module comprising: a drive coil that moves the magnet based on output signals from the third terminal portion and the fourth terminal portion of the Hall sensor.

Images