JPH0140511B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to thin film magnetoresistive elements.

The thin film magnetoresistive element is, for example, as shown in Japanese Patent Application Laid-open No. 74522/1983. Conventionally, permalloy (Fe
-Ni alloy) Al or Al alloy has been used as electrodes and wiring conductors, but when the permalloy film and Al are heated to 200 to 300°C or higher, atoms diffuse and react with each other. For this reason, the magnetic properties of the permalloy film are significantly deteriorated during the deposition of the Al electrode or during subsequent heat treatment. The present invention
In order to suppress the reaction between Al and permalloy film, Al
and permalloy between Mo, Cr, Ti, Ta, Nb,
It is characterized by providing a high melting point metal such as Pt or Zr as a reaction suppression layer. The diffusion coefficient of the above high melting point metal is
Al is very small compared to Fe and Ni, which are components of permalloy, and the reaction between Al and the above high melting point metal and between permalloy and the above high melting point metal is extremely small.
As a result, the reaction between Al and the permalloy film is completely suppressed, and the change in magnetoresistance of the permalloy magnetoresistive film is also suppressed.
There is no change at all when heated at 200-300°C. This manufacturing method has the same effect when using Au, Cu, and alloys thereof as wiring materials.

Example 1 In a magnetoresistive element having a structure consisting of a permalloy magnetoresistive film, an electrode/conductor film, a necessary insulating film, etc. on a desired substrate such as glass, after forming the magnetoresistive permalloy, the electrode/conductor metal is formed. Mo is deposited as a film to a thickness of 100 to 3000 Å, and then Al is deposited as a conductor to a required thickness, for example, 0.3 to 1 μm. At this time, if the Mo thickness is 100 Å or less, the film becomes a discontinuous island-like film, and the conductor Al and the permalloy film come into contact and react, making it useless as a barrier film. Therefore, a Mo film with a thickness of 100 Å or more is formed. On the other hand, if the thickness of the Mo film exceeds 3000 Å, the film may crack due to internal strain of the Mo film itself or peel off from the permalloy film, so it is desirable that the thickness of the Mo film is 3000 Å or more. As described above, in a magnetoresistive element with a structure in which a Mo barrier film is provided between an Al conductor and permalloy, permalloy and Al
Since this reaction is suppressed, the magnetic properties of permalloy do not deteriorate. For example, when an element with a structure provided with a Mo barrier film is heated at 300°C for 1000 hours, no deterioration is observed in the amount of change in magnetoresistance;
The amount of change in magnetoresistance for an element without a Mo barrier film is 1/
It deteriorates by 2 to 1/10. Therefore, the Mo barrier film exhibits an almost perfect effect.

Example 2 In a magnetoresistive element having the structure shown in Example 1, Mo was used as an electrode/conductor film with a thickness of 100 to 3000 Å.
Formed, then Al-4%Cu, Al-2%Mg,
No deterioration was observed in the amount of change in magnetoresistance when an element on which an alloy conductor film with low electromigration such as Al-2%Ni was formed was heated to 300 to 400°C.

Example 3 In a magnetoresistive element having the structure shown in Example 1, Mo was formed to a thickness of 100 to 3000 Å as an electrode conductor film, and then Cu, Cu-5% Al, Cu-2%
No deterioration was observed in the amount of change in magnetoresistance of the permalloy film after heating an element on which a conductor film such as Be was formed to 300 to 400°C.

Example 4 In a magnetoresistive element having the structure shown in Example 1, Cr was formed to a thickness of 100 to 2000 Å as an electrode/conductor film, and then Al, Al-4% Cu, Al-2%
No deterioration was observed in the amount of change in magnetoresistance of the permalloy film after heating an element on which a conductive film such as Ni, Cu, Cu-2%Be, Cu-5%Al, etc. was heated to 300 to 400°C. When using Cr as a barrier film, the lower limit of the film thickness is 100 Å like Mo, but if it exceeds 2000 Å, cracks may occur in the film.
Desirably 2000 Å or less.

Example 5 In a magnetoresistive element having the structure shown in Example 1, Ta was formed to a thickness of 100 to 3000 Å as an electrode/conductor film, and then Al, Al-4% Cu, Al-2%
No deterioration was observed in the amount of change in magnetoresistance of the permalloy film after heating an element on which a conductor film of Ni, Cu, Cu-2%Be, Cu-5%Al, etc. was formed to 300 to 400°C. The thickness of the Ta film is preferably 100 to 3000 Å for the same reason as in the above embodiment.

Example 6 No deterioration was observed in the magnetoresistive element having the structure shown in Example 1, in which Nb was formed as a barrier film, due to heating. Nb film thickness is 100~
3000 Å is desirable.

Example 7 No deterioration was observed in the amount of change in magnetoresistance after heating the element in which Ti and Zr were formed as barrier films of the magnetoresistive element having the structure shown in Example 1.

Example 8 Mo, Cr, Ta, Nb, Ti,
The device was heated to 300 to 400°C with Pt and Zr formed to a thickness of 100 to 3000 Å, and then a conductive film of Au of 0.3 to 1 μm thick.
No deterioration was observed in the amount of change in magnetoresistance of the element after heating.

Claims (1)

[Claims] 1. In a magnetoresistive element having a structure including a permalloy magnetoresistive film on a desired insulating substrate, an electrode/conductor film necessary for passing a current through the permalloy film, and an insulating film, a magnetoresistive element is provided on the permalloy film as an electrode. At least one thin film selected from Mo, Cr, Ti, Ta, Nb, Pt, and Zr is formed, and at least one film selected from Al, Cu, Au, and alloys thereof is formed on the thin film as a conductor. A magnetoresistive element characterized by being formed by forming.