JPS6145874B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a novel magnetically sensitive element and a method for manufacturing the same.

In particular, it relates to magnetically sensitive elements with novel electrodes and their manufacture.

Electrodes of magnetically sensitive elements manufactured using semiconductor thin films have traditionally been made of electrode-forming metal materials that are different from the semiconductor.
Pattern plating or pattern vapor deposition is performed, and since it is essential that the electrode has ohmic contact with the semiconductor thin film, different electrode forming metals are generally formed into two or three thin layers by plating or other methods. It is made of layers. For this reason, the conventional manufacturing of magnetically sensitive elements involves many complicated and troublesome electrode formation processes, as well as processes such as chemical plating, which are unfavorable for the thin film semiconductor, which is difficult in terms of quality and economy. However, there was a big problem.

The inventors of the present invention have carried out intensive research to solve this problem, and have found that when an appropriate amount of energy is irradiated onto the surface of a thin film of a compound semiconductor mainly composed of group and group elements, the irradiated area , the resistance value is greatly reduced, and it becomes a good conductor similar to metal, and the unirradiated part maintains its characteristics as a semiconductor without any loss, and furthermore, the irradiated part, which has become a conductor, is similar to the unirradiated part of a semiconductor. The inventors discovered a new phenomenon in which good ohmic contact exists at the boundary between the two, leading to the present invention.

The reason why a compound semiconductor thin film becomes a conductor due to energy irradiation as described above is because the irradiated part of the compound semiconductor thin film melts due to energy irradiation, changes from a semiconductor to an alloy state, and the resistance value decreases significantly. be done.

Furthermore, although the reason is not clear, it is very interesting that the energy irradiation part and the semiconductor part, which have been made conductive by such a method, show good ohmic contact. This is extremely important in terms of practical use of the device.

That is, the present invention is a magnetically sensitive element made of a compound semiconductor thin film, characterized in that a part of the compound semiconductor thin film is made conductive by energy irradiation to form an electrode, and a method for manufacturing the same.

According to the present invention, unlike conventional methods, it is not necessary to use a different metal as the electrode material for the electrode of the magnetically sensitive element, and processes such as chemical plating are not necessary for forming the electrode. Therefore, the transfer of impurities from the electrode to the semiconductor part, migration,
Furthermore, it is possible to provide an excellent magnetically sensitive element without deterioration of semiconductor characteristics, which is a problem during chemical plating.

According to the present invention, in the electrode formation of a magnetically sensitive element, the conventional multilayer chemical plating process is eliminated, and the process for forming the electrode is significantly simplified, and at the same time, pollution treatment such as plating waste liquid is also eliminated. It becomes necessary.

As described above, the present invention can provide highly reliable and high-performance magnetically sensitive elements that are industrially very advantageous.

The magnetically sensitive element in the present invention includes a Hall element made using a semiconductor, an element using the Hall effect, a magnetoresistive element, and an element using the magnetoresistive effect.

FIG. 1 shows a cross-sectional view of one example of the magnetically sensitive element of the present invention. 1 is the substrate of the element, 2 is the magnetically sensitive part of the magnetically sensitive element made of a compound semiconductor thin film,
3a and 3b indicate electrodes of a magnetically sensitive element made by converting the thin film into a conductor.

FIG. 2 is a top view of the magnetically sensitive element shown in FIG. 1, and 3a, 3b, 4a, and 4b are electrodes made of conductive semiconductors. 3a and 3b are input electrodes, and 4a and 44b are output electrodes.

The shape and size of the electrodes of the magnetically sensitive element of the present invention can be arbitrarily selected depending on the type of the element and its characteristics.

As the substrate for the magnetically sensitive element of the present invention, substrates conventionally used for magnetically sensitive elements can generally be used.

For example, ferromagnetic substrates include pure iron plates, silicon steel plates, permalloy plates, and various ferrite plates.

Further, as the non-magnetic substrate, a substrate made of metal, glass, ceramic, sapphire, etc., or a resin substrate, etc. can be used.

The surface of the substrate of the magnetically sensitive element of the present invention is coated with a polymer, sputtering, vapor deposition, ion plating, etc. for the purpose of insulating treatment or suppressing the transfer of impurities to the semiconductor thin film.

The compound semiconductor thin film used in the magnetically sensitive element of the present invention may be any compound semiconductor thin film that has been conventionally used as a compound semiconductor thin film, but compound semiconductors mainly composed of group and group elements are preferred.
For example, InSb, InAs, InP, InN, GaP, GaAs,
GaSb, GaN, AlAs, AlSb, AlP, AlN, BSb,
BAs, BN, InSbGa, InSbSn, InSb−NiSb,
GaAsP, GaAlAs, InGaP, etc. are used.

The semi-semiconductor thin film of the present invention includes single crystal, polycrystal, eutectic, etc., made into a thin film by a method such as polishing, a thin film produced by a method such as evaporation, ion plating, sputtering, etc., or a thin film produced by liquid phase growth. A thin film produced by a method such as a method or a vapor phase growth method can be used.

The thin film referred to in the present invention is a semiconductor thin film commonly used in magnetically sensitive elements, and generally has a thickness in the range of about 0.1 to 100 μm.

The electrodes of the magnetically sensitive element of the present invention are formed by irradiating a semiconductor thin film with an appropriate amount of energy in the shape of an electrode.

As the energy source, for example, Xe lamp light, laser light, electron beam, heat ray, etc. can be used.

As the irradiation method, energy beam scanning or pattern irradiation using a mask can be used.

When irradiating energy through a mask, a commonly used mask can be used depending on the type of energy.

By irradiating the semiconductor thin film with an appropriate amount of energy in this manner, the semiconductor thin film in the irradiated portion can be made conductive, and an electrode integrated with the semiconductor portion can be formed.

However, regarding the irradiation energy, there is a threshold value determined by the type and thickness of the compound semiconductor thin film, the substrate on which the thin film is formed, etc., and the thin film cannot be made into a conductor with an energy amount below the threshold value.
Furthermore, if the amount of energy is too large, the semiconductor thin film will be destroyed and electrodes cannot be formed.

The amount of energy for conductivity in the present invention is
It depends on the energy intensity and irradiation time, and therefore, the amount of irradiation energy can be controlled by both the energy intensity and the irradiation time. By applying this, a semiconductor thin film can be made conductive from the surface to a desired depth. In order to make semiconductor thin films conductive with more precise patterns, methods are used to increase the energy intensity and shorten the irradiation time.

Next, a method for manufacturing a magnetically sensitive element according to the present invention will be explained in detail with reference to FIG.

Energy is applied to the electrode portions of the substrate 1 and the compound semiconductor thin film 2 formed thereon through a mask having a desired electrode shape or by scanning. In this way, the portion of the semiconductor irradiated with energy becomes a conductor, forming electrodes 3a and 3b.

In FIG. 3, pattern irradiation of energy using a mask 5 is shown. Arrows indicate energy irradiation. Further, the unirradiated area is indicated by 2 and is a compound semiconductor thin film.

As described above, the magnetically sensitive element of the present invention has good ohmic contact between the electrode and the semiconductor portion, and is small in size, highly sensitive, and highly reliable.

The manufacturing method of the present invention is a method of directly forming electrodes by irradiating energy in a pattern, and is advantageous as a mass production process because it is a dry process, has a small number of steps, and can create any electrode pattern with high precision. . That is, the present invention provides a magnetically sensitive element having excellent characteristics and an economical mass production process thereof.

Next, the method for manufacturing the magnetically sensitive element of the present invention will be described in detail with examples, but the present invention is not limited thereto.

Example 1 On a square ferrite substrate with a thickness of 0.5 mm and a side of 5 mm, an InSb vapor-deposited film with an electron mobility of 15000 cm ² /V sec was formed in a pattern as shown in Figure 2 (encircled by a thick line frame). .

Next, a chrome mask made by vapor-depositing chromium was used on the glass plate, and a Xe lamp was used to irradiate flash light with a pulse width of 100 μsec.

Input electrode 3 made by making the semiconductor into a conductor in this way
A Hall element having output electrodes 4a and 4b was fabricated.

The width of the magnetic sensing part 2 was 1.5 mm and the length was 3.0 mm, and the output electrodes were taken out from both ends of the magnetic sensing part at a width of 0.3 mm. The input and output electrodes are large to facilitate attachment of lead wires to the outside.

Next, lead wires were attached to the input and output electrodes using In-Sn solder, and the entire device was molded with epoxy resin.

The thus manufactured Hall element had an unbalanced voltage of 1.2 mV at an input control current of 5 mA and a magnetic field of 0, and a Hall output voltage of 150 mV at an input control current of 5 mA and a magnetic flux density of 1 KG.

In a moisture resistance test, the device of the present invention showed a 20% improvement in moisture resistance and higher reliability compared to a device fabricated using a conventional method with two-layer electrodes of chemically plated copper and silver. Ta.

Example 2 An InSb single crystal thin film with an electron mobility of 75,000 cm ² /V·sec was formed on a square ferrite substrate with a thickness of 0.5 mm and a side of 5 mm in a pattern as shown in FIG. 2 (indicated by a thick line frame). .

Next, a chrome mask made by vapor-depositing chromium was used on the glass plate, and a Xe lamp was used to irradiate flash light with a pulse width of 100 μsec.

Input electrode 3 made by converting the semiconductor into a conductor
A Hall element having output electrodes 4a, 4b and output electrodes 4a, 4b was fabricated.

The width of the magnetic sensing part was 1.5 mm and the length was 3.0 mm, and the output electrodes were taken out from both ends of the magnetic sensing part at a width of 0.3 mm. The input and output electrodes are large to facilitate attachment of lead wires to the outside.

Next, lead wires were attached to the input and output electrodes using In-Sn solder, and the entire device was molded with epoxy resin.

The thus manufactured Hall element had an unbalanced voltage of 0.3 mV when the input control current was 5 mA and a magnetic field of 0, and a Hall output voltage of 50 mV when the input control current was 5 mA and the magnetic flux density was 1 KG.

Furthermore, the device of the present invention has the following properties in a moisture resistance test:
Compared to conventional devices with chemically plated two-layer electrodes of copper and silver, the device has improved moisture resistance by 20% and has higher reliability.

[Brief explanation of the drawing]

FIG. 1 shows a cross section of the Hall element of the present invention. FIG. 2 is a top view of the Hall element shown in FIG. 1. FIG. 3 shows a cross section of the Hall element electrode of the present invention formed by energy irradiation. Arrows indicate irradiated energy beams.

Claims (1)

[Scope of Claims] 1. A magnetically sensitive element made of a compound semiconductor thin film, characterized in that a part of the compound semiconductor thin film is made conductive by energy irradiation to serve as an electrode. 2. A magnetically sensitive material comprising the step of irradiating a part of a compound semiconductor thin film with an appropriate amount of energy, thereby making the irradiated part a conductor and forming an electrode that makes ohmic contact with the unirradiated part. Device manufacturing method.