JPH02111084A - Magneto-electric conversion element - Google Patents

Abstract

PURPOSE:To improve stability and reliability at high temperature by forming a III-V compound semiconductor where a Hole element is formed on a supporter with an organic insulation layer consisting of heat-curing resin whose glass transfer temperature exceeds 230 deg.C on the surface. CONSTITUTION:In a compound semiconductor layer used, a compound semiconductor thin film such as InAs, InSb, and GaAs is formed on a mica film, passivation layers 13 and 16 are further formed on it, the mica film is eliminated from a thin film, and a compound semiconductor thin film 14 of a semiconductor such as InAs, InSb, and GaAs is formed on a substrate 11 such as GaAs, sapphire, and silicon. A heat-curing resin with a glass transfer point of 230 deg.C which is an organic insulation layer 12 is used. Preferably, the minimum viscosity on heat curing should be 1 poise or less. Heat-curing resin should be polyimide resin, imide-modified epoxy resin, etc. It improves stability and reliability at high temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetoelectric variable element that detects a magnetic field and outputs a signal.

[Conventional technology] +! Several structures of Hall elements using IV group compound semiconductors are known. For example, i) directly deposit Si on a III-V group compound semiconductor single crystal substrate such as GaAs;
A structure in which elements such as the following are implanted by ion implantation to form a sensitive part to form a device, a single crystal substrate of a III-V group compound such as GaAs, a single crystal such as sapphire, or a substrate of glass, ceramics, etc. Sensitivity of III-V compound semiconductor thin films by MBE or vacuum evaporation
There is a structure in which an i part is formed, an electrode is formed on it, and an element is formed. In addition, 1f) - A thin film formed by cross-plating a III-V compound semiconductor on a smooth surface such as mica is adhered to a support such as ferrite or alumina with an adhesive that is an organic insulating layer, There are structures in which the mica on the surface is removed and then turned into elements, and structures in which the semiconductor layer of (i) above is bonded onto a ferrite or the like to increase the hole output. In particular, structure ii) has the advantage of being able to easily exhibit excellent performance (for example, by using ferrite, etc., a large Hall output can be obtained) by appropriately selecting the material of the support, and is widely used. It is being However, these Hall elements have recently gone beyond the scope of home appliances in which they have been used up until now, and are beginning to be used in various fields including the automobile field. In these new fields, the usage conditions are becoming stricter, such as heat resistance being required.

The Hall element of the type ii) above, in which the compound semiconductor layer and the support are bonded with an organic insulating layer, has features such as high sensitivity and is desired to be used in high temperature ranges. , there is a lack of comprehensive consideration of the adhesive and the compound semiconductor layer, such as how to use the adhesive, and although there is no problem in the normal temperature range, if the element is heated excessively, the unbalanced voltage and resistance will increase. Fluctuation phenomena were also observed, and stability at high temperatures,
Not reliable enough.

[Problem to be solved by the invention] Until now, thermosetting resin adhesives used to bond Hall elements and as organic insulating layers have focused on the adhesive strength, moisture resistance, and handling properties of the resin, and their chemical structure Therefore, resins having a glass transition point of about 150°C to 180'C are widely used. However, for these resins, the temperature is 2 below the glass transition point.
The elastic modulus decreases from 0 to 30℃ lower temperature, and from 130℃ to
When exposed to temperatures of 150°C, unbalanced voltage changes and resistance fluctuation phenomena have also been observed. Furthermore, when the adhesive exceeds its glass transition point, the coefficient of thermal expansion becomes several times as large.
At such high temperatures, the above-mentioned problems become even more serious. Therefore, if an adhesive with a low glass transition temperature is used, the device will be heated during device assembly (wire bonding), so if impact load from the capillary or large horizontal vibrations due to ultrasonic waves are applied,
This causes a large displacement on the brittle resin surface, which tends to cause cracks in the chip on the top of the resin, and the range of allowable operating conditions is narrowed, which is a major problem during mass production. This is the current situation.

The object of the present invention is to provide a pole element having a structure in which a compound semiconductor chip on which a Hall element is formed is adhered to a support with an adhesive, which is an organic insulating layer, at a high temperature [1, ? It is an object of the present invention to provide an extremely suitable Hall element which can be industrially mass-produced and which improves the stability and reliability of the device.

[Means for Solving the Problems] ;t; The present invention was achieved as a result of the inventors' earnest efforts to eliminate the above-mentioned drawbacks.

That is, in the present invention, a III-V group compound semiconductor layer with a Hall element formed thereon is formed on a support having an organic insulating layer on the surface, and the organic insulating layer is heated to a temperature with a glass transition temperature of 230° C. or higher. It is characterized by being a curable resin.

The compound semiconductor layer is made by forming a compound semiconductor layer of InAs, InSb, GaAs, etc. on mica by MBE method or vapor deposition method, and then forming a passivation layer on top of it, and then forming a thin layer of 119 or GaAs with mica removed. , InAs, InSb on substrates such as sapphire, silicon, etc.
, compound semiconductors such as GaAs, MBE method, LPE method,
A thin film formed by a CVD method, a JIOCVD method, or an evaporation method, or a film formed by ion implantation of Ga onto a substrate is used.

There are no particular restrictions on the support on which the hemibody layer is placed, but
For example, magnetic oxides such as Mn4n ferrite and Ni-Zn ferrite, high magnetic permeability metal materials such as permalloy, or ceramic materials such as alumina, aluminum nitride, and silica.

Alternatively, an amorphous material such as glass or a single crystal such as sapphire may be used.

The thermosetting resin used as the organic insulating layer of the present invention has a glass transition point of 230° C. or higher, and more preferably has a minimum viscosity of 1 void or less during thermosetting.

The thickness of the organic insulating layer is not particularly limited and is 60 μm or less, preferably 204 μm or less. There are no particular restrictions on the structure of the thermosetting resin, but polyimide resin is preferred.

Imide-modified epoxy resin, lipophilic epoxy resin.

Examples include glycidylamine-based epoxy resins. The passivation layer may be any material as long as it has the effect of preventing moisture from entering from the outside, herroken, etc., but preferably,
Inorganic thin films such as Al2O2, SiO, and Si3N4 are used, but in some cases, organic polymers such as polyimide may be used.

[Function] According to the present invention, the adhesive resin serving as the organic insulating layer between the compound semiconductor chip and the support on which the compound semiconductor is mounted has a glass transition temperature of 230°C or higher, and is preferably thermoset. By using a resin with a minimum viscosity of 1 void or less, it is possible to create a thin adhesive layer that is heat resistant, and even when used at high temperatures where heat resistance is required, unbalanced voltage and resistance changes are small. A stable and highly reliable Hall element can be manufactured. Furthermore, by using a resin having the above-mentioned characteristics, the temperature during wire bonding can be controlled to be below the glass transition point of the resin, thereby further increasing the reliability of industrially mass-produced devices. In addition, when the pole element is formed in a compound semiconductor layer or a compound semiconductor thin film, Db? By applying a passivation film to the lower part of the resin, it is possible to use the resin at high temperatures even if the resin has the above-mentioned characteristics or has poor moisture resistance. Examples are shown below, but the present invention is not limited to these Examples.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

Example 1 FIG. 1 shows a cross section of an embodiment of the present invention.

A thin film of InAs was formed on mica having a smooth surface by the M8E vapor deposition method to produce a semiconductor 11U14. Furthermore, AJ2203 (thickness 0
．． 3 μm) thin film 13 was formed by vacuum evaporation. The glass transition temperature of this AJ2203 thin n-surface is 250℃.
Polyimide resin 12 (Toshiba Chemical CT430)
It was coated with a ferrite substrate 11 having a thickness of 0.3 mm and a square shape of 50.8 mm on each side, and then the mica was removed. Thereafter, an electrode 15 was formed using a photoresist by a commonly used method, and a pattern of a magnetically sensitive part was formed. The passivation layer 16 that protects the magnetically sensitive part is made of An203 (thickness: 03 μm).
) A thin film was formed by a vacuum evaporation method, silicone resin was further applied, and a ferrite chip 42 was mounted on it to create a Hall element wafer. Next, this wafer was cut with a guissing cutter to create chips. Chip lead frame 2
The electromagnetic part 15 of the pellet and the lead frame 22 were bonded by wire bonding. Then, molding was performed using resin 23 to create a Hall element. Table 1 shows the change (average) and deviation in the unbalanced voltage Vu before and after the solder heat resistance test of this Hall element. The solder heat resistance test herein refers to changes in characteristics before and after immersing four terminals of an element in a semi-solid phase at various temperatures for 10 seconds. Furthermore, Table 2 shows the failure rate of the elements during the solder heat resistance test.

Table 1 Technique] Heat resistance test (unbalanced voltage change) Unit mV73V [νυ change (average 1-dimensional deviation) Table 2 Element defective rate Defective rate is 1Vu (initial value - ras)・after) 1≧5,'
OmV ratio comparative example 1 Adhesive resin 12 in Example 1 was replaced with polyimide resin (Toshiba Chemical TVB2703A glass transition temperature 172
℃), and otherwise produced a device in the same manner as in Example 1. The heat resistance test results are the first. Shown in Table 2.

As shown in Tables 1 and 2, the device according to the present invention has a small unbalanced voltage change and a small defective rate after the heat resistance test.

Example 2 A Hall element was produced in the same manner as in Example 1 except that the ferrite substrate in Example 1 was replaced with an alumina substrate and the ferrite chip 42 was not mounted. Table 3 shows the changes and deviations in unbalanced voltage before and after the solder heat resistance test of this Hall element.

Comparative Example 2 An element was manufactured in the same manner as in Example 2 using the same adhesive resin as in Comparative Example 1. The results of the heat resistance test are shown in Table 3.

Table 3 Solder Heat Resistance Test Unit mV/:IV Example 3 A device was produced in the same manner as in Example 1 except that the passivation layer in Example 1 was replaced with SiOx (thickness: 0.5 μm). Table 4 shows the results of the solder heat resistance test for this Hall element, and Table 5 shows the element failure rate.

Comparative Examples 3 to 5 Elements were fabricated using the same fabrication method as in Example 3 using adhesive resins having different glass transition points. Table 4 shows the solder heat resistance test results of this Hall element, and Table 5 shows the element failure rate.

Glass transition point Resin name Table 4 Solder heat resistance test Unit mV/3V Table 5 Element defect rate Those with ΔVul≧5mV were judged as defective.

As shown in Tables 3 to 5, the device of the present invention exhibits superior heat resistance to the comparative example even when no magnetic northeast ferrite is used and regardless of the type of bashing film.

Example 4 On a GaAsn/L crystal substrate with a mirror surface (
- A [nAs thin film with a thickness of 1 μm and an electron excitation of 10.000 cm2/Vsec] was
A semiconductor IT model was fabricated by heteroepitaxial growth using the BE method. Next, a polyimide resin having a glass transition temperature of 250°C is applied to the surface of the GaAs substrate to a thickness of 0.
It was adhered to a square ferrite substrate with a diameter of 3 mm and a side of 50.8 mm. From this point on, a TnAs Hall element was fabricated using the same fabrication method as in Example 2. As a result of a solder heat resistance test of this Hall element, the difference (average) deviation in unbalanced voltage at 300° C. was 0.51+0.43 mV/3V.

Example 5 The semiconductor film to be formed on mica in Example 1 was changed to InSb, and from then on, the same manufacturing method as in Example 1 was used.
An InSb Hall element was created. The result of a solder heat resistance test using this element was that the unbalanced voltage change (average) deviation was 0.91±0.48 mV/3V at 10°C.

Example 6 Si3 as the passivation layer 16 in Example 1
An InAs Hall element was fabricated using the same fabrication method as in Example 1 except that N4 was formed to a thickness of 0.5 pm by the PCVD method. As a result of a soldering heat resistance test using this element, the unbalanced voltage change (average) deviation was 0.60±0.25 mV/3V at 300°C.

Actual 71λ Example 7 Aj2 as passivation layer 1δ in Example 1
203 (0,3μm) and Sin□ (0,3μm)
An InAs Hall element was fabricated using the same fabrication method as in Example 1 except that a thin film was formed by vacuum evaporation. Using this element, we conducted a high-temperature current test (150°C, 20mA,
500 hours). The results are shown in Table 6.

Comparative Example 6 The adhesive resin in Example 7 was replaced with polyimide resin (Toshiba Chemical, TVn27038, curing agent Percure HV1).
06. A device was produced in the same manner as in Example 7 except that the glass transition temperature was changed to 172° C.). A high temperature energization test was conducted using this element. The results are shown in Table 6.

Table 6 High temperature energization test ΔRjn Deviation Δ in rate of change of input resistance before and after test
Rout Deviation Δ in rate of change of output resistance before and after test
Deviation in absolute value of rate of change of unbalanced voltage before and after Vul test Example 8 GaA with a square with one side of 50.8 mm and a mirror surface
A semiconductor layer was formed by implanting St ions into an S single crystal substrate by an ion implantation method. Next, a polyimide resin with a glass transition temperature of 250°C was applied to the back surface of the GaAs substrate, and it was adhered to a square ferrite substrate with a thickness of 0.3 mm and a side of 5 (1.8 mm). A GaAs Hall element was fabricated using a similar fabrication method.

The result of the solder heat resistance test of this Hall element is that the difference (average) in voltage at 300℃ is 0.45±0.
．． It was 41m1//:IV.

[Effects of the Invention] As explained above, according to the present invention, excellent heat resistance can be achieved regardless of the type of compound semiconductor scale, the type of passivation film, the type of substrate, and regardless of the presence or absence of a ferrite chip for magnetic focusing. It can be used at high temperatures.

15... Electrode, 16... Upper passivation layer, 22... Lead frame, 23... Mold resin, =+1... Silicone resin (adulent), 12... Ferrite chip, 50...Tie bond adhesive resin layer.

[Brief explanation of the drawing]

1 is a sectional view of an embodiment of the present invention. 11... board, 12...Organic insulating layer (contact agent), 13... lower passivation layer, 14...Semiconductor device

Claims (1)

[Claims] (1) A III-V compound semiconductor layer on which a Hall element is formed is formed on a support having an organic insulating layer on the surface, and the organic insulating layer has a glass transition temperature of 230°C.
A magnetoelectric conversion element characterized by being made of the above thermosetting resin.