JPS63119590A - Magnetoelectric transducer - Google Patents

Abstract

PURPOSE:To make it possible to form a highly sensitive magnetoelectric transducer having a high Hall mobility and to simplify manufacturing process, by forming a crystallized film of ZnO on an insulating substrate, and forming a film comprising an In compound such as InSb or InAs on the crystallized film. CONSTITUTION:A crystallized film 12 of zinc oxide (ZnO) is formed on a substrate 10 having insulating property. A crystal film 13 of an In compound comprising InSb, InAs or the like is formed on said crystallized film. Thus a highly sensitive magnetoelectric transducer having a high Hall mobility is obtained. The Hall mobility of a Hall element using a substrate with said ZnO film is larger than the Hall mobility of a Hall element using a substrate without a ZnO film by about 2-4 times within a range of substrate temperature of, e.g., 300-500 deg.C. The value of 20,000-45,000 cm<2>/V.S is obtained as the Hall mobility with good reproducibility.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to magnetoelectric transducers such as Hall elements and magnetoresistive elements, and particularly to magnetoelectric transducers with high Hall mobility.

(Conventional example and its problems) Conventionally, an InSb film with crystallinity has a hole mobility μ that affects the sensitivity of a power generation conversion element, ranging from several hundred to several tens of thousands of Cm2/v.
Since it has a very large S and is used as a magnetically sensitive film, it is widely used as a material for magnetoelectric effects such as high-sensitivity Hall elements or high-sensitivity resistance effect elements.

Usually, InSbIll is formed on a substrate such as glass, silicon, glazed ferrite, mica, etc. by vacuum evaporation method, sputtering method, ion blating method, cluster ion beam evaporation method, etc. However, the degree of crystallization varies greatly depending on the film formation method, which greatly affects the magnitude of hole mobility.

The method for forming the InSb film is described in Patent Nos. 1008790 and 101.
No. 3921, JP 57-152175゜Special Publication 1986-
34829, etc., but in particular, a method for forming an InSb film having high sensitivity characteristics is disclosed in Japanese Patent Publication No. 51
-45234. As disclosed in "Transactions of the Institute of Electrical Engineers of Japan Vol. 80, No. 857, P36" published in February 1960, there is a method of using mica as a substrate and directly forming an InSb film on this substrate by vacuum evaporation. Disclosed. Generally, it is known that the properties of a deposited film such as InSb are better when deposited on a substrate with a crystal structure as close as possible to that of the material for which it is deposited. It is also known that a so-called heteroepitaxial film can be grown by appropriately setting the film striations, even in the case where mica, a crystalline silicate mineral, is used as a substrate for InSb films When used as
This is believed to be the reason why it is possible to form a highly sensitive InSb film.

However, mica has erectile properties and is therefore weak in strength, and has the drawback of poor long-term reliability when used as a thin film substrate for an element.

Therefore, Japanese Patent Publication No. 51-45234 discloses a method in which InSb III formed on a mica substrate is bonded onto a ferrite substrate via an epoxy resin, and then the mica is peeled off. However, there are problems in that it requires a complicated adhesion process and a peeling process, resulting in an increase in the number of man-hours and a decrease in the yield rate, resulting in an increase in cost.

(Means for Solving the Problems) The present invention has been made to solve the above problems, and consists of forming a crystallized film of zinc oxide (ZnO) on an insulating substrate, and InSb or In
The present invention provides a magnetoelectric transducer characterized by forming a crystalline film of an In compound made of As or the like.

(Example) In the present invention, when forming a crystalline InSb film on a substrate, the inventors have conducted numerous experiments to find a material for the substrate that can easily form the heteroepitaxial relationship. This was based on several facts discovered in the

FIGS. 1A to 1C are schematic explanatory diagrams of main steps showing an embodiment of the present invention, and the manufacturing method and the structure of the magnetoelectric transducer will be explained below using the same figures.

The first step is as shown below, and Fig. 1(a')
As shown in the figure, a substrate 10 made of ferrite material is prepared,
An insulating film 11 made of SiO2, glass, or the like is formed on the surface of this substrate 1o by known thin film forming means.

The second step is as shown below, and as shown in FIG. 1(b), ZnO (zinc oxide) III 112 is formed on the insulating film 11 by high-frequency ion blasting. Zn 01112 (7) Created in 1937
“Transactions of the Institute of Electronics and Communication Engineers, published in May 2015, 791.5
vol, 62-CNo, 5. As described in detail in Machida et al., metal Zn is evaporated in a chemically active atmosphere of low temperature plasma of oxygen to form a ZnO film 1.
2 is synthesized on the substrate 10, but this Zn
011! The preparation conditions are summarized in Table 1. Further, although the film forming conditions that the ZnO film 12 created in this manner should have vary depending on the film forming method, at least the crystal plane (O○2) of the ZnO film 12 is formed parallel to the substrate surface 11a. That is what we are doing.

Figure 2 shows Zn formed by high frequency ion blating method.
This is a graph showing the X-Ray diffraction pattern of 011112, in which the horizontal axis represents the 2θ diffraction angle and the vertical axis represents the relative intensity of the diffraction lines. According to Figure 2, the 26 diffraction angle is approximately 3
A diffraction peak of the crystal plane (002) appears at an angle of 2°, and it is considered that the larger the diffraction peak value and the smaller the half width, the better the crystallinity.

The third step is as shown below, and as shown in FIG. 2(C), I
The nSb film 13 is formed by a vacuum evaporation method, and the conditions for forming the 1n3b film 13 at that time must at least satisfy the setting ranges of each item shown in Table 2.

Table 1 Conditions for creating ZnO film InSb film 1 on substrate 10 obtained by the above steps
3 is formed into a plurality of Hall element groups having a predetermined shape by a photolithography process, and then a single Hall element is obtained by cutting the substrate. Furthermore, it is well known that the substrate temperature during film formation is one of the factors that determines the quality of the crystallinity of InSb.

FIG. 3 shows the substrate temperature at the time of forming the InSb film 13 for a Hall element manufactured using a substrate with a ZnO film according to the present invention and another Hall element manufactured under the same conditions except for a substrate without a ZnO film. It is a graph showing the relationship with hole mobility μ.

As is clear from Figure 3, the substrate temperature is 300 to 500℃.
Within the range of , the Hall mobility of the Hall element using the ZnO film-coated substrate according to the present invention is about 2 to 4 times larger than that of the Hall element using the ZnO film-free substrate. 20,000 to 4 as Hall mobility μ
Values of 5,000 cm2/v and s were obtained with good reproducibility.

The film exhibited good film quality in terms of adhesion and smoothness, and was able to confirm sufficient practicality for application to Hall elements and magnetoresistive elements.

The crystallinity of the 1nSb film 13 varies depending on the crystallinity quality of the ZnO film 12 as well as the deposition conditions of the n3b film 13, but in this example, under the conditions shown in Table 2, Hall mobility μm 20,000CIl12/v, S
A highly sensitive film as described above has been obtained.

In the above example, Zn 01! The J12 film formation method was explained using the high frequency ion blating method as an example, but sputtering method, CVD (Camical
Vaper DeposiNon) by Zn
011912 may be formed. In short, in the X-Ray diffraction pattern shown in Figure 3,
(ZnO where the diffraction peak of the 002> plane is clearly observed
If film 12 is used, the desired high sensitivity In5bll! 1
3 is obtained. In addition, as the substrate 1o, an example has been described in which an insulating film 11 made of a SiO2 film or a glass film is formed on the surface of the substrate 10 made of a ferrite material.
0 does not necessarily have to be a substrate made of ferrite material; for example, a substrate with ZnO film 12 formed directly on an insulating substrate made of glass (for example, Corning 7056) or ceramic material may be used. I on top
n Sb II! Even if I is formed, an electromagnetic transducer with high hole mobility and high sensitivity can be obtained.

As another example, on a substrate with a ZnO film, 1n3
An In AS film was formed under the same film formation conditions as the b film, and
A Hall element was created from this in AS g by photolithography, and the hole mobility of the resulting Hall element was about 2 to 4 times higher than that of a substrate without a ZnO film, similar to that of InbsIll. The inventors have confirmed that an 15AS film having high hole mobility can be obtained.

(Effects of the Invention) As described above, the magnetoelectric transducer of the present invention includes a crystallized Zno film formed on an insulating substrate, and a film made of an ln compound such as InSb or InAs on this crystallized film. By forming a film, it is possible to create a highly sensitive magnetoelectric transducer with a hole mobility that is approximately 2 to 4 times larger than that of a magnetoelectric transducer in which a film of an ln compound such as InSb or InAS is formed on a substrate without a ZnO film. becomes.

In addition, since the substrate is made of a strong and chemically stable material such as ferrite or glass, there is no need to provide a separate reinforcing substrate like when using a mica substrate, and the manufacturing process As a result of being able to simplify the process, it is advantageous in terms of cost as well as making it possible to manufacture a highly reliable magnetoelectric transducer.

[Brief explanation of the drawing]

FIGS. 1(a) to (C) are schematic explanatory diagrams of the main steps showing one embodiment of the present invention, and FIG. 2 is a graph showing the X-RaV diffraction pattern of a ZnO film formed by high-frequency ion blating method. Figure 3 shows the results of In
Substrate temperature and hole mobility μ during film formation of 5 blll
This is a graph showing the relationship between 10... Substrate, 11... Insulating film, 12... ZnO
Membrane, 13-In Sb II. Base] Oversight (0) Figure 3

Claims (1)

[Claims] A magnetoelectric transducer characterized in that a crystallized film of zinc oxide (ZnO) is formed on an insulating substrate, and a crystallized film of an In compound made of InSb, InAs, etc. is formed on the crystallized film.