JPS60218890A - Manufacture of thin film for magnetoresistance element - Google Patents

Abstract

PURPOSE:To obtain a thin film having a large DELTAR effect, by evaporating Cu-Al alloy including 0.1-5wt% of at least one or more metals, which are selected from the group of transition metals and Sm, and forming a film on a substrate. CONSTITUTION:Cu-Sm alloy (0.07wt% Sm and Cu for remaining part) as an evaporating material is inputted to glass as a substrate material in an electron beam evaporating device. The inside of a vacuum tank is evacuated down to 5X10<-5>Torr or less. Then methane gas is introduced in the vacuum tank at the partial pressure of 0.8X10<-4>Torr, and the Cu-Sm alloy is evaporated. Thus a film having a thickness of 1,000Angstrom is formed. Within the range of the partial pressure or 1X10<-4>-5X10<-2>Torr, the DELTAR effect of Al-Cu alloy including 0.1- 5wt% of alloy elements is larger than that of Ni-Cu alloy regardless of the kind of gas and also regardless of the kind of alloy elements.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a metal film for a magnetoresistive element having a large magnetoresistive effect.

[Prior art and its problems]

In recent years, the rotation speed of servo motors used in NC machine tools, etc.
Rotary magnetic encoders are used to accurately measure rotation angles. This encoder is composed of a magnetic drum and a magnetic sensor, and the magnetic sensor uses a metallic magnetoresistive element that is stable against temperature changes.

Recently, as the resolution of encoders has become higher, there has been a demand for higher performance magnetoresistive element materials.

If the magnetoresistive effect (ΔR effect) of the magnetoresistive element is small, S
Since the /N ratio becomes small, it is necessary to make the distance between the sensor and the magnetic drum as close as possible. As a result, it becomes expensive because it requires advanced processing technology. Current magnetoresistive element materials include Ni--Fe and Ni--Co, which have a ΔR effect of 4 to 6%, and are made into thin films by sputtering, but the characteristics are insufficient.

For example, a material with a large ΔR effect of 11% is
Powder and Powder Metallurgy, 27.6 (1980) P2O
7 (Chino, Takagi). This material is made by dispersing carbides of transition metals or Sm in the grain boundaries of Cu or AI, and is a bulk material made by a sintering method, but a method for making its thin film has not yet been established.

[Purpose of the invention]

An object of the present invention is to provide a manufacturing method for making this material into a thin film and obtaining a thin film with a large ΔR effect.

[Structure of the invention]

The present invention is to manufacture a film made of a material having a large magnetoresistive effect, in which a 1-transition metal or a 5I11 carbide is dispersed in Cu or AI, and will be described below based on Examples.

First Example> In an electron beam evaporation apparatus, glass as a base material and Cu-3m as an evaporator (Sm 0.07% by weight, balance Cu) were placed in an electron beam evaporation apparatus, and the vacuum chamber was heated to 5 x 10-'Torr.
Exhaust below. Next, 0.0% methane gas was introduced into this vacuum chamber.
The Cu-5I11 alloy was evaporated by introducing at a partial pressure of 8 x 10-'Torr.

After forming a film with a thickness of 1000 mm, the influence of alloy composition and gas partial pressure on the ΔR effect in a magnetic field of 1000 e was investigated, and a ΔR value of 6.0% was measured. Also, by changing the partial pressure of methane gas from lXl0-' to 7X10-'', Δ
The R value was measured. Next, add 0.1% by weight of Sm to C with the balance being Cu.
Also for u-5m alloy, methane gas is 0.8×10-'
The Cu-3+w alloy was introduced at a partial pressure of ~7 x 10 Torr to evaporate it to form a film with a thickness of 1000 mm, and the ΔR value was measured in a magnetic field of 1000 e.

These results are shown at the top of Table 1.

Regarding hydrocarbon gases other than methane (propane, ethane, butane), and alloys other than Cu-3m (Cu-Fe
+ CLI-Fe2C, 'AI-'Sm, Al-Fe
, 81-Fe5C), results similar to those of the Cu-5e alloy were obtained.

In addition, Cu-Co, Cu-Mn, Cu-Ni,
Experiments similar to the above were also conducted for Al-Co and Al-Ni+AI=Mn.

The results are shown at the bottom of Table 1.

In this first example, regardless of the type of gas, the partial pressure is in the range of lXl0-' to 5XlO-'' Torr, and the alloying element is contained in an amount of 01.1 to 5% by weight, regardless of the type of alloying element. 1. Regarding Cu alloy, ΔR effect is different from Ni-Cu
It turned out to be larger than the alloy. In addition, 8ONi-20
C.

The ΔR value of the alloy is 6.48%.

Table 1 (Second Example) In an electron beam evaporation apparatus, Al-Fe alloys having various compositions were placed on a glass plate as a base material and as an evaporation material,
The inside of the vacuum chamber is evacuated to 5X10-' Torr or less, and then propane gas is evacuated to 6X10-' to 7XIO-
"Introducing at a partial pressure of Torr and applying a negative voltage to the substrate creates a plasma state in the tank. In this state, the alloy evaporates,
A film with a thickness of 1,000 people was formed. Next, ΔR of this sample
The effect was investigated in the same manner as in the first example, and the influence of alloy composition and gas partial pressure on the ΔR effect was investigated.

Hydrocarbon gases other than propane gas (methane gas,
Similar experiments were conducted for ethane gas, butane gas) and for alloys other than ^l-Fe. The results are shown in Table 2.

In this example, the partial pressure is 5xt regardless of the type of gas.
A containing 0.1 to 5% by weight of alloying elements regardless of the type of alloying elements, in the range of
1. It was found that the ΔR effect was larger for the Cu alloy than for the Ni-Co alloy.

Table 2 *For FoJC, Pe is not included. Third Example> A Cu-Fe+C alloy target is placed in a high-frequency sputtering device, and the inside of the vacuum chamber is evacuated to 2X 10-'Torr or less. Next, add ethane gas to 3 x 10-” ~ 4 T
sputtering was carried out under the conditions of RF power of 500 W to form a film with a thickness of 1000 mm, and ΔR
The influence of alloy composition and gas partial pressure on the effectiveness was investigated.

Similar experiments were conducted on hydrocarbon gases other than ethane gas (methane gas, propane gas, butane gas) and on alloys other than Cu-Fe5C. The results are shown in Table 3.

In this example, the partial pressure is 5X1 regardless of the type of gas.
AI containing 0.1 to 5% by weight of alloying elements, regardless of the type of alloying element, in the range of 0-3 to 3 Torr.

It was found that it was larger than the Cu alloy.

Table 3 *For pe3C, the Fe content is
(AA)g and Cu(AA)z ((^A) represents acetylacetonate) were introduced at a blending ratio of 0.0008 to 0.06, and a film was deposited on heated quartz glass.

Next, the effects of blending ratio and heating temperature on the ΔR effect of this film were investigated.

5LIIJ? ) Complex compounds other than Cu or alkoxides and complex compounds of Cu or AI, or alkoxides are mixed at a weight ratio of 0.001 to 0.05 of only metal elements, and deposited on a substrate heated to 300 to 950°C. It can be seen that if this is done, a film with a large ΔR effect can be obtained.

At temperatures below 300°C, thermal decomposition does not occur, and at temperatures above 960°C, the film aggregates, so the ΔR value could not be measured.

Table 4 [Effects of the Invention] As described above, according to the present invention, a thin film for a magnetoresistive element having a large ΔR effect can be obtained, so that a high-performance magnetic sensor can be produced.

Claims (1)

[Claims] 1. Any single gas or a mixture of two or more gases selected from the group of methane, propane, ethane and butane maintained at a pressure of 1 x 10-' to 5 x 10-' Torr. C containing 0.1 to 5% by weight of at least one metal selected from the group of transition metals and Sva.
A method for producing a thin film for a magnetoresistive element, comprising forming a film on a substrate by evaporating a u+ A1 alloy. 2. The method for producing a thin film for a magnetoresistive element according to claim 1, wherein the transition metal or SLl is in the form of a carbide. 3. In any single gas or mixture of two or more gases selected from the group of methane, propane, ethane and butane maintained at a pressure of 8 X 10-5 to 5 X 10-'' Torr. A film is formed on the substrate by evaporating Cu, A1 alloy containing 0.1 to 5% by weight of at least one metal selected from the group of transition metals and Sm while a part of the gas is ionized. 4. A method for manufacturing a Wi film for a magnetoresistive element according to claim 3, wherein the transition metal or SLl is in the form of a carbide. 5. 5X10-" Methane held at a pressure of ~3 Torr. 0.1 to 5% by weight of at least one metal selected from the group of transition metals and Sm in any single gas or mixed gas of two or more selected from the group of propane, ethane, and butane. Contains Cu or AI or Sm-C
1. A method for producing a thin film for a magnetoresistive element, comprising forming a film on a substrate by sputtering using an o alloy as a target or using a plurality of metal elements corresponding to the alloy composition as targets. 6. The method for producing a thin film for a magnetoresistive element according to claim 5, wherein the transition metal or SL1 is in the form of a carbide. 7. The weight ratio of a substance containing at least one of transition metals or S- complex compounds and alkoxides to a substance containing i or more of Cu or AI complex compounds, alkoxides, and acetates in terms of metal components. 0.00
Production of a thin film for a magnetoresistive element characterized by forming a film by introducing the film into a reduced pressure hydrogen atmosphere at a ratio of 1 to 0.05 and thermally decomposing it on a substrate heated to 300°C to 950°C. Method.