JPS60208882A - Magnetoelectric conversion element - Google Patents

Abstract

PURPOSE:To make it possible to perform bonding at low temperature, in a magnetoelectric conversion element having a compound semiconductor film on an insulating substrate, by forming an intermediate layer having a different hardness between an electrode forming bonding layer and the semiconductor film. CONSTITUTION:A semiconductor film 14 is formed on an insulating substrate 11, and an electrode 15 is formed thereon. The electrode 15 is composed of a contact layer 16 which connects the semiconductor film 14, an intermediate layer 17 thereon and a bonding layer 18 on the layer 17. The intermediate layer 17 comprises a material, whose Young's modulus is larger than that of the bonding layer 18. Thus the wire bonding of a wire 21 to the bonding layer 18 can be performed at a low temperature by using ultrasonic waves having low energy. Therefore thermal stress is not concentrated in the interface between the insulating substrate and the semiconductor film due to the heat yielded at the bonding and the insulating substrate in not separated from the semiconductor film. These improvement are achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magneto-electric conversion element, such as a Hall element or a magnetoresistive element, which converts a magnetic field or magnetic flux into an electric signal.

<Prior art> Conventional - The electrode structure of a magnetoelectric transducer using a group semiconductor is made by forming an ohmic contact on a semiconductor layer, and then forming a metal layer with good wire bondability such as Au + Aj by a vapor deposition method. A method is used in which this is heated to around 300 to 400° C. and a thin wire of Au+AI or the like is connected by pressure bonding or ultrasonication. However, when this method is applied to a compound semiconductor film formed on an insulating substrate or a substrate having an insulating layer on the surface, two problems arise.

Since the -f'ith substrate or insulating layer and the compound semiconductor layer have different coefficients of thermal expansion, the temperature cannot be raised sufficiently during bonding. 300 as is normally done
When the temperature of the electrode portion is raised to ~400° C., thermal stress is generated at the interface between the insulating layer and the semiconductor film, resulting in a decrease in reliability or peeling between the insulating layer and the semiconductor thin film. Second, the insulating layer and the semiconductor film generally do not have sufficient adhesion, and peeling occurs when ultrasonic waves of high power and energy are applied.

In addition, the thickness of the semiconductor layer is usually as thin as 0.1 to 10 μm,
Furthermore, since a ■-■ group compound semiconductor generally has a small Young's modulus and is brittle, the semiconductor layer itself is destroyed by the application of high-power ultrasonic waves.

<Structure of the Invention> The object of the present invention is to form a compound semiconductor thin film with a thickness of 0.1 to 10 μm formed on an insulating substrate, that is, a substrate itself made of an insulating material or having an insulating layer on its surface, at a low temperature. It enables high-yield and highly reliable wire bonding using low-energy ultrasonic waves, greatly improving the yield of magnetoelectric transducers, dramatically increasing the reliability essential to sensors, and making industrial use possible. The purpose is to supply extremely large pedomatous AT conversion molecules.

According to this invention, the thickness is 0.
．． 1~10μm 1 electron density is 5X101''~5X1
A high mobility compound semiconductor film of the at-V group with an electron mobility of 2,000 to 80,000 c#/Vaec at room temperature is formed, and a desired portion on the semiconductor film is formed. An electrode is formed on the intermediate layer having a large Young's modulus, and a bonding layer with a smaller Young's modulus and good bonding properties is formed on the intermediate layer. 1s of Hall element which is one of the elements
An example of this structure is shown in Figures 1 and 2. In Figure 1,
The insulating substrate 11 of the Hall element is constructed by forming an insulating layer 13 on a substrate 12 that is not an insulating material. A semiconductor film 14 with high electron mobility constituting a magnetically sensitive part is formed on an insulating substrate 11, and a wire bodding electrode 15 is formed on the semiconductor film 14. This electrode 15 is the semiconductor film 1
4, an intermediate layer 17 thereon,
Furthermore, there is a bonding layer 18 thereon.

The semiconductor film 14 in the center between the electrodes is a magnetically sensitive part 19 . The electrode 15 is connected to a lead frame 22 with a thin wire 21 made of Au+Aj+AJS heavy alloy or the like. The substrate 11, the thin #21, etc. are embedded in the resin mold body 23, leaving the ends of the lead frame 22 intact.

Figure s2 shows the case where the insulating substrate 11 of the Hall element is made of only an insulator, and in particular does not have the insulating layer 13 on the surface.

FIG. 3 shows the Hall element shown in FIG. 1 or 2 exposed from above.

4 and 5 show examples in which the Hall element chip is directly attached to the printed wiring board without using the lead frame 22. FIG. That is, the thin wire 21 is connected to the wiring 25 formed on the printed circuit board 24.

In this embodiment, the wire bonding electrode 15 includes a contact ld l 6 , an intermediate layer 17 , and a bonding layer 18 .
It consists of 3 nos. A bonding layer 18 that is a metal layer with good bonding properties and a contact layer 16 that ensures ohmic contact with the semiconductor and alleviates thermal stress at the interface.
By interposing an intermediate layer 17 such as a metal layer that is harder than these layers 16 and 18 between the bonding layer 1 and the bonding layer 1, ultrasonic energy applied during bonding can be transferred to the bonding layer 1.
8, and in response to ultrasonic shock or thermal shock,
Semiconductor film on insulating substrate 11 that does not have sufficient resistance*
In contrast to No. 14, it is possible to form a highly reliable wire bonding joint at a low temperature and by applying low power ultrasonic waves.

The bonding layer 18 is made of AuvAu, PT.

It is made of a metal with good wire bondability, such as AI + AI S heavy alloy, 'Ag + Cu, or an alloy thereof. The metal used for this layer 18 may be any metal as long as it has good wire bonding properties, but Au is particularly preferred. This layer 18 has 11 poles 15 and Au + AI + AJ
This ensures a strong and reliable connection with the Hosomaro 21 made of -8i alloy or the like. For forming the bonding layer 18, methods used for forming electrodes of ordinary semiconductor devices, such as electroless plating, '1tps plating, and lift-off using fish scraps or sputtering, are used. The thickness of the bonding layer 18 is not particularly limited, but is usually 0.1 to 30
μm1 is preferably 0.1 to 10 μm. In order to improve the reliability of bonding, it is preferable that the bonding layer 18 be thick, but as the layer thickness increases, internal stress increases, resulting in a decrease in adhesion at the layer interface, a decrease in etching cut, and a decrease in Ag. When using noble metals such as + Au l P , the upper limit is determined by the increase in price.

When using a metal that is easily oxidized, such as Cu + Aj, for the bonding layer 1B, a very thin J- layer of a metal that is difficult to oxidize, such as Au + Ag, is formed on the surface, and a plurality of bonding layers (18) are formed. This also improves bonding reliability. FIG. 6 shows the cross-sectional shape of this 'electrode 15. In Figure 6, H
A bonding body layer 26 of the 4i group, such as Cu or Aj, which has good bonding properties but is easily rusted, is formed, and a thin metal layer 27 such as Au or Ag, which has good bonding properties and is not easily rusted, is formed on the bonding body layer 26. Then, the bonding layer 18 is formed by the bonding body layer 26 and the metal thin layer 27. l on the bonding body layer 26
When using k, care must be taken in forming the thin metal layer 27.

Aj is the instantaneous oxidation force 1 in air. It is preferable to form the bonding body layer 26 and the metal thin layer 27 continuously in a vacuum or in a reducing atmosphere.

Further, even when a metal such as Ag or Pt that is not susceptible to acid oxidation is used for the bonding layer 18, reliability is further increased by forming a very thin layer of Au, which has excellent bonding properties, on the surface thereof. FIG. 7 shows its cross-sectional structure. On the intermediate 7117, a metal 1-28 other than Au, such as Ag or Pt, which has good honting property and is resistant to rust, is formed,
A thin layer 29 of Au is formed on the metal 1@28.

The intermediate layer 17 is made of Ni + Fe + Ti + W + Cu
The bonding layer 18 is made of a metal l- which is harder than the bonding layer 18 such as +, and can be formed by a method such as a non-dL'Is plating method, an electrolytic plating method, a lift-off method using fish scraps or sputtering, or the like. The effects of this intermediate J-17 mainly consist of the following three points.

(a) During bonding, the force acting perpendicularly to the surface of the t-pole 15 is concentrated on this intermediate layer 17, and this force is applied to the semiconductor Ji! 114 or the interface between the semiconductor film 14 and the contact layer 16.

(b) The load during bonding is distributed over the entire electrode 15 to prevent the load from being concentrated only on the tip of the tool.

(e) The ultrasonic waves are reflected at the interface between the intermediate layer 17 and the bonding layer 18 to prevent the ultrasonic waves from adversely affecting the semiconductor film 14 or its interface. At the same time, the ultrasonic wave key is concentrated on the bonding layer 18, ensuring reliable bonding with the low power ultrasonic wave key.

For the purpose of this (aJ or (b)), the intermediate l-17 has a larger Young's modulus than the bonding layer 18 or the contact layer 16, and is preferably a metal having a large elastic limit.

When placing importance on the effect (c), it is preferable to use a metal that makes the sound speed in the bonding layer 18 or the contact layer 16 as different as possible from the sound speed in the intermediate layer 17. At this time, because the sound velocity mismatch is large, the bonding layer 1
The ultrasonic waves are reflected by the interface between the contact layer 8 and the intermediate layer 17 or the interface between the contact layer 16 and the intermediate layer 17. A preferable example of a metal that satisfies the above conditions is Ni*Cu.
There is r W -b'. It is preferable to use Au for the bonding J@ 18 and the contact layer 16, but the preferable metal for the intermediate layer 17 has a Young's modulus more than twice that of Au, and the sound velocity is about twice that of Au. become. When the bonding layer 18 is made of Au, the intermediate layer 17 is made of Cu.
It is also preferable to use

The thickness of the intermediate layer 17 is not limited to the above, but is usually 0.1~
The thickness is preferably 30 μm, preferably 0.1-10 μm.

In order to effectively exhibit the effect of the intermediate layer 17, it is preferable that the layer thickness be as large as possible; however, as the layer thickness increases, internal stress increases, the density of the layer interface decreases, and etching breaks. There is an upper limit because it is easy to do. middle layer 17
If the intermediate layer 17 is made too thin, its mechanical strength will be low and ultrasonic waves will easily pass through it, so there is no point in providing the intermediate layer 17.

In order to effectively reflect ultrasonic waves, it is preferable that the intermediate layer 17 is composed of a plurality of metal layers.

If metals with significantly different sound velocities in adjacent layers are assembled, each time an ultrasonic wave passes through an interface, it will be reflected depending on the degree of mismatch between the sound velocities of the metals on both sides of the interface, and its amplitude will be significantly attenuated. do. An example of this configuration is shown in FIG. In FIG. 8, the bonding layer 18 is composed of an Au layer, and a Ni layer 31, an Au layer 32, and a Ni layer 33 are sequentially laminated thereunder, and the intermediate layer 17 is formed by these three layers 31, 32, and 33. . Ultrasonic waves are layer 18 and layer 31, layer 31 and layer 32, layer 3
It is reflected at a total of four interfaces: 2 and layer 33, and 33 and layer 16.

It is sufficient that the intermediate layer 17 has a difference of 50% or more from the bonding layer 18 in overall characteristics such as Young's modulus (hardness), elastic limit, and difference in noble velocity.

The contact layer 16 is made of Cu, , Au, , At, kl-
Forms good ohmic contact with compound semiconductors such as 8i alloy, Au-Ge alloy, Ag, Pt, or alloys thereof, has a coefficient of thermal expansion similar to that of the compound semiconductor, and has a similar coefficient of thermal expansion to the compound semiconductor. Consists of a soft metal layer.

Through this contact layer 16, the semiconductor film 14 and the electrode 15
This ensures good ohmic contact with the semiconductor film 14 and the electrode 15, and alleviates thermal stress between the semiconductor film 14 and the electrode 15. To form the contact layer 16, an electroless plating method, an electrolytic plating method, a lift-off method using vapor deposition or sputtering, or the like is used. Layer thickness is not particularly limited, but is usually 0.1 to 50μ
m1 is preferably kio, 1 to 10 μm. In order to improve the reliability of bonding, it is preferable that the contact layer 16 be thick, but as the layer thickness increases, internal stress increases, the adhesion of the layer interface decreases, and etching breakage decreases. When using noble metals such as Ag1AulPt, there is an upper limit due to the increased price.

When using a semiconductor in which it is difficult to form an ohmic contact such as GuAs or InP, or when using the contact layer 16
If you do not want to use a large amount of expensive metal such as A u + Pt e A g, contact jtlJ l
6 is made into a plurality of layers, first, the semiconductor film 1 is formed with a thin layer of Au-Ge, etc.
After forming an ohmic contact with the semiconductor film 14, a metal that is softer than the intermediate layer 17 or a metal whose coefficient of thermal expansion is closer to that of the semiconductor film 14 than the intermediate layer 17 is formed thereon.
The layer forms a contact layer 16. An example of this is shown in FIGS. 9 and 10. In FIG. 9, the semiconductor film 14 is made of Ga.
v In the case of an As layer, a Ge alloy layer 34 is formed on this semiconductor M14. The ratio of Ge in this alloy layer 34 is between 0.1 and 103,
a. Ensure ohmic contact between the As semiconductor film 14 and the electrode 15. A Cu layer 35 is formed on the Au-Ge alloy layer 34, and the contact layer 16 is formed by adding 34.35. In FIG. 1O, the semiconductor film 14 is made of InAs.
x5bt −x (o<x<i) 118, an Au layer 36 is formed on this semiconductor film 14,
A Cu layer 37 is formed on the seven AuM 136, and these two
A contact/1ii16 is formed in layer 36.37.

For forming the contact holes 111i16, methods commonly used for forming electrodes of semiconductor devices, such as electroless plating, electrolytic plating, and lift-off by vapor deposition or sputtering, are used. The thickness of the contact layer 16 is not particularly specified, but is preferably 0.1 to 10 μm. In order to improve the reliability of bonding, it is preferable that the contact layer 16 be thicker, but as the layer thickness increases, internal stress increases, the adhesion of the layer interface decreases, the etching breakage decreases, and the contact layer 16 becomes thicker. When using precious metals, the upper limit of price increase is determined.

If the metal used for the intermediate layer j7- forms a good ohmic contact with the semiconductor film 14 and has good adhesion to the semiconductor film 14, the contact 4416 may be omitted. At this time, the metal used for the intermediate layer 17 has a coefficient of thermal expansion close to that of the semiconductor film 14, and has a Young's modulus that is not so large compared to the semiconductor film 14, but is larger than that of the bonding layer 18. Preferably poisonous. An example of this configuration is shown in FIG. In FIG. 11, on a platform using InAsx8bt-x (0≦×1) as the semiconductor layer 14, a Cu layer is formed directly on the semiconductor layer 14 as an intermediate Nl 17, and a bonding layer 18 is formed on the Cu layer. An Au layer is formed.

The substrate 11 of the element of the present invention may be one used in general magnetoelectric transformation elements, such as a single crystal or sintered ferrite substrate, a ceramic substrate, a glass substrate, a silicon substrate,
A sapphire substrate, a semi-insulating GaAs substrate, an nP substrate, etc., a heat-resistant resin substrate, a substrate made of ferromagnetic iron, permalloy, etc. whose surface is insulated are used.

The insulating layer 13 on the surface of the substrate is preferably an inorganic insulating layer, particularly an oxide or nitride insulating layer, or a wax insulating layer. The insulating layer of oxide or nitride is normally used for insulation treatment coating on the surface of the substrate, and alumina, 5i(h), silicon nitride, or a mixture or multilayer insulation layer of these is preferably used. .Also, the thickness is
In the case of an inorganic insulating layer, the thickness is usually 10 μm or less.
It is formed by a method such as snowdrop, chemical vapor deposition, (CVD), or molecular beam deposition. The resin insulator layer 13 is usually
Substrate 11 and high mobility semiconductor film 14. As the adhesive layer, resin, commonly used thermosetting epoxy resin, phenol epoxy resin, etc. are used. Further, the thickness of the insulating layer 13 is not particularly limited, but is preferably 60 μm or less.

The magnetically sensitive semiconductor film 14 is preferably a high-mobility semiconductor thin film used as a normal magnetoelectric transducer, and is made of InSb +
GaAs + I nSb + GaAs, I
nAs, bSySrm InxAvPz.

InxGaySbz (x+y+z=2), I
Electron transfer g2. UUO~80,001Jan'/Vs
IP, single crystal or polycrystalline thin films are used within the EC range.

The electrode 15 of the magnetoelectric conversion element is electrically coupled to a conductor such as a lead frame 22 or a wiring pattern 25 formed on a printed circuit board by a thin wire 21 made of Au+Aj+Aj-8i alloy or the like which is normally used for wire bonding. When connecting to the lead frame 22, the material of the lead frame may be Cu, J-bronze, or the like, which is used for leads of ordinary semiconductor devices. Furthermore, in order to improve bonding properties, it is also preferred to form a thin layer of a metal with good bonding properties, such as A u + A g, on the surface of the lead.

In the case of wiring on the printed circuit board 24, the printed circuit board 24 used may be one used for the wiring of ordinary electronic components. It is also preferable to form a thin layer of Au+Ag or the like having good bonding properties on the wiring conductor.

゛　、　Ro　゛　°　Ro　.

+11 0 − °.

The material of the mold resin 23 may be a resin generally used for molding electronic devices. Preferred are thermosetting resins, such as epoxy resins and phenol epoxy resins. The molding method may be a method used for ordinary electronic components, such as evaporation, cast molding, transfer molding, placing a solid pellet on the element, heating and melting it, and then hardening and molding. .

Although the Hall element has been described above as an example of the magnetoelectric transducer of the present invention, other elements such as magnetoresistive elements may also be used such as the Hall element, the shape of the electrodes, the number of terminal electrodes, and the pattern of the magnetically sensitive part. However, the electrodes are formed in the same way as the Hall element, and the basic configuration is the same.

The present invention will be explained below using specific examples, but the present invention is not limited to these examples, but extends to all magnetoelectric transducers having the basic structure described above.

First Example A semiconductor film 14 was formed by vacuum evaporating an InSb thin film having a thickness of 1 μm and an electron mobility of 30.000 aIr/V sec on a single-crystal mica substrate with a smooth surface. Next, a 3.00 OA thick AjzO,s layer was formed thereon by vacuum evaporation. The surface of this AJzOs thin film is coated with epoxy resin, and a ferrite substrate 12 is formed into a square shape with a thickness of 0.3+++a+ and a − side of 4511Iffl.
layered on top. The mica was then removed. After that, using photoresist, In
A 7-photoresist film was formed on the surface of the magnetically sensitive part of the Sb thin film. Next, conduct electroless plating to coat copper to a thickness of 0.3 μm.
m was attached only to the required areas. Furthermore, in order to thicken the copper, electrolytic copper plating was performed to form a contact layer 16 with a thickness of 4 μm. Next, using the above photoresist again, an intermediate layer 17 of a Ni layer having a thickness of 2 μm was formed only on the electrode portion by electrolytic plating. A bonding layer 18 of AuJ- with a thickness of 2 μm is formed on it by electrolytic plating.
was formed. Next, using the above photoresist again, the unnecessary InSb thin film and some unnecessary - were removed by etching with a hydrochloric acid solution of i@2 iron chloride by photolithography, and the magnetically sensitive part of the Hall element was removed. and four electrode parts were formed. Later, a ferrite chip for magnetic convergence was glued using silicone resin directly above the magnetically sensitive part. Next, apply this wafer 1- to a guissing cutter, 1. I
It was cut into square Hall element chips of x 1.1 am. This was then adhered onto the die of lead frame 22. Next, the pellet electrode 15 and the lead frame 22 were bonded together on the Aua wire 2 using a high-speed wire bonder.

Packaged using epoxy resin using transfer molding method.

The failure rate of the Hall element manufactured in this manner to which the present invention was applied during wire bonding was as shown in (■) in Table 1.

In Table 1, Table 3@Table 1, ■ indicates the case where the Ni layer of the intermediate layer 17 is omitted and the Cu layer, which is the contact layer 16, is made to have a thickness of 6 μm. (2) is the case where a 2 μm thick Au layer was directly formed on the Jn'Sb thin film. (2) is a case in which an intermediate layer 17 of a 6 μm Ni layer is formed on InSb, a bonding layer 18 of a 2 μm Au layer is formed thereon, and the Ni layer serving as the intermediate layer 17 also serves as the contact layer 16. In each case, the temperature of the element during bonding was 100°C. Also, the ultrasonic energy is chosen in each case to minimize the failure rate. Also, the number of samples is 2.0 each.
0'0 comes out. The defective rate is a value per one junction. Those with a tensile strength of 2 g or less between the electrode and the Aua wire 2 were judged to be defective. Regarding the causes of failure in each case, ■ is mostly due to insufficient strength of the bond between the Au wire 21 and the electrode, and ■ is due to insufficient strength of the bond between the Au layer and the electrode, and the gap between the semiconductor film and the Altos layer. There were almost the same number of chestnuts. Regarding (2), most of the damage was caused by peeling between the semiconductor film and the AhOi layer.

As for (2), most of it was a foil between the Ni layer, the semiconductor, and the film. The above results reveal the following two points.

(2) When the intermediate layer 17 is present, the defective rate is drastically reduced compared to when it is not present.

(2) If the contact layer 16 is omitted even when the intermediate layer 17 is inserted, the defective rate will increase.

Also, due to the cause of the failure, it can be seen that when the intermediate layer 17 is blown off, the ultrasonic energy is concentrated between the semiconductor film 14 and the AItOs layer, and when the contact flj 16 is omitted, it is concentrated between the intermediate layer and the semiconductor film.

The cross-sectional structure of the above element is shown in FIG. In FIG. 12, an epoxy resin layer 13a and an alumina layer 13b constitute an insulation 1@13. A ferrite 42 which is a magnetic convergence chip is placed on the magnetically sensitive part 19 via a silicone resin layer 41.
is attached.

Second example: An InAs film with a thickness of 1.2 μm and an electron mobility of 10.000 at/Vsec was deposited on a mica substrate with a smooth surface using the MBE method (
It was formed using a molecular epoxy resin. Next, a 1,000 layer of 5 ift thick was formed on the semiconductor film by vacuum evaporation. On this 5iOJii, the thickness is 0.3 fin - the side is 45
The failure rate during ear bonding was as shown in Table 2.

Table 2 In Table 2, ■ indicates the case where the present invention was applied, and ■ indicates the case where the intermediate Ni layer was removed and the Cu layer serving as the contact layer was made to have a thickness of 6 μm. ■ is 2 directly on the InA3 thin film.
μm+7) When an Au layer is formed. ■ is InA+
A 6 μm Ni layer is formed on the s\MI film, and an Au layer is formed on it.
This is a case where the layer is formed to have a thickness of 2 μm, and the intermediate Ni layer also serves as a contact layer. In each case, the temperature of the element during bonding was 100°C. Also, the ultrasonic energy is selected in each case so as to minimize the defective rate. Further, the number of samples was 4000 for each, and the defective rate was a value per l junction. Also, 1i
E and others and Au#i? Those with a tensile strength between IMs of 2 g or less were judged as defective. Regarding the causes of failure in each case, ■ is due to insufficient strength between the Au11111 and the electrode, ■ is due to insufficient strength between the Au wire and the electrode, and - foil between the semiconductor film and the Sing layer. There were almost the same number of shi. Regarding (2), most of the failures were due to peeling between the semiconductor film and the 5iOz layer. ■For #1 Tondoka Ni layer and I
It was a foil between the nSb layers.

As a result of the above, we understand the following two points.

■ With a middle tier, the
The defective rate is drastically reduced.

(2) If the contact layer is omitted even when the intermediate l-layer is used, the defective rate will increase.

Furthermore, as a cause of failure, it can be seen that when the intermediate layer is removed, the ultrasonic energy is concentrated between the semiconductor film and the Sing layer, and when the contact layer is omitted, the ultrasonic energy is concentrated on the intermediate layer and the semiconductor film.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of an AT conversion element according to the present invention, FIG. 2 is a sectional view showing another embodiment of the invention, FIG. 3 is a plan view of FIG. 1, and FIG. A plan view of another embodiment, FIG. 5 is a sectional view of FIG. 4, and FIG. 6 is a bonding layer 1.
8 shows an example of an electrode structure when the electrode structure consists of multiple metal layers.
IT plan view, FIG. 7 is a sectional view showing another example of the electrode structure when the bonding layer consists of a plurality of metal layers, and FIG. 8 shows an electrode structure when the intermediate layer consists of a plurality of metal layers. FIG. 9 is a cross-sectional view showing an example of an electrode structure when the bonding layer is made up of multiple metal layers, and FIG. 10 is a cross-sectional view showing an example of the electrode structure when the bonding layer is made up of multiple metal layers. FIG. 11 is a cross-sectional view showing another example of the t-pole structure when the intermediate layer also serves as a contact layer, and FIG. 12 is a cross-sectional view of the Hall element of the first example. DESCRIPTION OF SYMBOLS 11... Insulating substrate, 12... Substrate, 13... Insulating layer, 14... Semiconductor film, 15... Electrode, 16...
・Contact layer, 17... Intermediate layer, 18... Bonding layer, 19... Magnetically sensitive part, 21... Wire bonded Jinpeng wife, 22... Lead frame, 2
3... Mold @BFl, 24... Pudding) d board,
25... M pattern on the print base, 26...
・Layer with good bonding properties and easy to rust, 27... Metal with good bonding properties and easy to rust, 28... Metal other than Au with good bonding properties and easy to rust, 29 =
Au layer, 3l-=Ni layer, 32-Au layer, 33-=Ni
Layer, 34...Au-Ge alloy layer, 35-...Cu1f
lJ, 36-Au layer, 3l-Cu layer, 42...ferrite. Patent Applicant Asahi Kasei Kogyo Co., Ltd. Agent Kusano Kurumadon 1 Figure】5 7j72 Figure-111~-w '7I'73 Ryodon 4 Figure 7175 Figure 71=6 Figure O 7 Figure 7178 Figure O 9 Figure "7P10 Figure 71711 Figure 24121 115

Claims (1)

[Claims] (1) A 1n-v group compound semiconductor film with a thickness of 0.1-10 μm and an electron mobility of 2.000-80.000aIP/V sec is formed on an insulating substrate, and an intermediate layer is formed on the semiconductor film. and a bonding layer is formed on the intermediate layer to constitute an electrode, and the intermediate layer is made of a metal material harder than the bonding layer.