JPS6013318A - Production of thin film magnetic head - Google Patents

Abstract

PURPOSE:To produce a thin film magnetic head provided with 2mum or more magnetic layer with high etching accuracy by forming lower and upper layers consisting of reactive metal and performing the ion beam etching of a magnetic layer in the atmosphere of mixing gas consisting of inert gas and oxygen gas. CONSTITUTION:When titanium, reactive metal, forming the lower layer 2 and the upper layer 4 and ''Permalloy'' forming the magnetic layer are etched by ion beams in the atmosphere of the mixing gas consisting of argon gas and oxygen gas, the etching rate of the titanium is extremely reduced, but that of the permalloy is not reduced so sharply. Therefore, a pattern of photoresist 5 is formed on the upper surface of the upper part layer 4 and then the formed pattern is etched by ion beams in the atmosphere of argon gas to form the mask pattern of the upper part layer 4. Subsequently, the formed layers are etched by ion beams in the atmosphere of the mixing gas consisting of argon and oxygen. Since the etching rate of the upper part layer 4 is extremely reduced, the thickness of the upper part layer 4 may be thin and the magnetic layer 3 can be etched with high resolution.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a thin film magnetic head having a magnetic layer of 21 nm or more, and an object of the present invention is to manufacture the head with higher accuracy than ion beam etching.

Conventionally, chemical etching methods have been adopted for etching when manufacturing various electronic components, but it is difficult to obtain sufficient manufacturing precision with this etching method.
In addition, problems such as pollution will arise.

Therefore, dry etching methods have begun to be adopted in place of chemical etching methods, and in particular, ion beam etching, which is a type of dry etching method, has attracted much attention because it has various characteristics such as the ability to etch a wide variety of materials. ing.

Ion beam etching is a process in which plasma is generated using a dedicated plasma generation device to perform etching.
Argon gas, which is an inert gas, is used for etching gas cleaning, and since argon gas is chemically inert, the etched portion of the material to be etched is removed from the surface of the material by a physical process.

However, although ion beam etching can etch all kinds of materials, it has the drawback of low selectivity.

In other words, since there is not much difference between the etching rate of the resist film and the etching rate of the material to be etched,
For example, when etching a thick material, it is necessary to form a resist film to a considerable thickness in advance.

When the resist film is made thicker, the so-called I9 resolution decreases and the etching accuracy decreases, making it difficult to use it for manufacturing thin-film magnetic heads.

By the way, beam etching is performed using argon gas (Ar gas).
For example, if the process is carried out in an atmosphere of a mixed gas of 80% argon gas and 20% oxygen gas (Arorr), titanium (T) reacts with oxygen.
It is known that in the case of reactive metals such as i), chromium (Cr), aluminum (Az), and molybdenum (Mo), the etching rate is extremely lower than that in an argon gas atmosphere.

On the other hand, a thin-film magnetic head is formed by laminating one or more magnetic layers made of a ferromagnetic material such as Permalloy. S102) On the insulating layer of the lining,
For example, vacuum evaporation or sputtering: (Thus, if the magnetic layer film is directly formed, the stress strain inside the layer may cause warpage in the substrate, and the adhesion between the insulating substrate and the magnetic layer or the insulating layer may warp. The adhesive force between the magnetic layer and the magnetic layer is weakened, so-called film peeling occurs, and the magnetic head becomes useless.

Therefore, when manufacturing a thin film magnetic head having a thick magnetic layer, that is, a magnetic layer with a thickness of 2 μm or more, an adhesive layer is formed between the substrate or the insulating layer and the magnetic layer, and an adhesive layer is formed between the magnetic layer and the magnetic layer. It is also necessary to form an adhesive layer between the layers and the upper layer to prevent the film from peeling off.

This invention has been made with the above points in mind,
In a method of manufacturing a thin film magnetic head having one or more magnetic layers having a thickness of 2 μm or more, a lower layer for adhesion and an end stop made of a reactive metal film such as titanium, chromium, aluminum, molybdenum, etc. an upper layer for adhesion and masking consisting of the magnetic layer and the reactive metal film is formed on the lower layer, and the upper layer is heated in an atmosphere of an inert gas such as argon gas. The present invention provides a method for manufacturing a thin film magnetic head, characterized in that the first magnetic layer is etched with an ion beam in an atmosphere of a mixed gas of the inert gas and oxygen gas.

Therefore, according to the method of manufacturing a thin-film magnetic head of the present invention, the lower layer and the upper layer are formed from reactive metals, and the magnetic layer is ion beam etched in a mixed gas atmosphere, so that magnetic layers other than reactive metals are etched. The etching rate of the layer is faster than the etching rate of the lower and upper layers, and the thickness of the upper layer that forms the mask pattern of the magnetic layer can be made thinner. It can be manufactured with higher etching precision than beam etching.

Further, the lower layer and the upper layer form an adhesive layer, which can prevent the magnetic layer from peeling off.

Next, the present invention will be described in detail with reference to drawings showing one embodiment thereof.

First, when titanium, which is a reactive metal, and permalloy, which forms a magnetic layer, are ion beam etched in an argon gas atmosphere, and when the partial pressure of oxygen gas is 1Q Tor,
The etching rate when performing ion beam etching in an atmosphere of a mixed gas of R will be explained.

Under the specified etching conditions, the etching rate for titanium in an argon gas atmosphere is 300A77.
min, the etching rate in a mixed gas atmosphere is 5OA,'min, and in the case of permalloy, the etching rate in an argon gas atmosphere is 40OA.
,'min, and the etching rate in a mixed gas atmosphere is 30OA,/min'g. It goes without saying that each etching rate changes by changing the current and voltage of the ion beam.

In other words, titanium, which is a reactive metal, has a markedly lower etching rate in a mixed gas atmosphere, while permalloy has a lower etching rate under the etching conditions.

Therefore, as shown in Figure 1, a
Lower adhesion and end stop layer (2) consisting of a titanium film by vacuum evaporation or sputtering.

A magnetic layer (3) made of a permalloy film and an upper layer (4) for adhesion and masking made of a titanium film are formed in this order. In addition,
The substrate (1) may be any insulating layer such as silicon dioxide on a conductive substrate.

Next, as shown in FIG. 2, a pattern of photoresist (5) is formed on top of the upper layer (4) by a conventional photolithography technique.

After applying the photoresist, ion beam etching is performed in an argon gas atmosphere, and the upper layer (4) is ion beam etched to form a mask pattern for the upper layer (4), as shown in Figure 3. .

Note that when forming the pattern of the photoresist (5), the photoresist (5) will be completely etched until the ion beam etching of the upper layer (4) is completed. Of course, the thickness of (5) must be set in advance.

Next, after forming the mask pattern of the upper layer (4), the atmosphere gas for ion beam etching is changed from argon gas to a mixed gas of 80% argon, 5. Then, ion beam etching is performed on the magnetic layer (3) as shown in FIG. 4, and the etching of the magnetic layer (3) is completed.

Then, during etching of the magnetic layer (3), the upper layer (4)
Since the enotinic layer 1 of the upper layer (
The thickness of step 4) may be thin, and the magnetic layer (3) can be etched with good resolution, and the magnetic layer (3) can be etched with high precision.

As shown in FIG. 4, the thickness of the upper layer (4) is set so that the upper layer (4) remains when the etching of the magnetic layer (3) is completed. , for example -1, is used as part of the bonding when a new layer is bonded on top of the sublayer (4).

Furthermore, after the etching of the magnetic layer (3) is completed, the lower layer (2) is removed by chemical etching or ion beam etching as required.

By the way, when actually manufacturing, the etching rate of the titanium film forming the lower layer (2) and the upper layer (4) and the Sulpermalloy film forming the magnetic layer (3) with argon gas and mixed gas must be set accurately in advance. It is necessary to measure the

Further, the partial pressure of oxygen gas needs to be set so that the etching rate ratio between the titanium film and the permalloy film is as large as possible and the reproducibility is good.

For example, when the reproducibility is set to -10%, the etching rate of a titanium film in an argon gas atmosphere is 30OA,/min, and the etching rate of a titanium film in a mixed gas atmosphere is 5QA,/min. rnin 1
In addition, the etching rate of the permalloy film in an argon gas atmosphere is 400A/min, and the etching rate of the permalloy film in a mixed gas atmosphere is 300λ.
/min, the thickness of the magnetic layer (3) is 37
zm, the thickness of the upper layer (4) is 61.1OA or more based on the following equation.Also, when the magnetic m(3) is etched with an ion beam, the etching rate of the titanium film changes drastically, and the permalloy Of course, it is necessary to control the etching conditions very precisely to the optimum conditions so that the etching rate of the film does not change too much.

When forming a magnetic head by ion beam etching the magnetic layer (3) in a mixed gas atmosphere, for example, even if the thickness of the magnetic layer (3) is 3 μm, the thickness of the upper layer (4) forming the mask pattern is As mentioned above, the knowledge agreement 611OA
That's fine.

On the other hand, when forming a photoresist pattern on the top of aH[(3) and etching the magnetic layer (3) with an ion beam in an argon gas atmosphere to form a thin film magnetic head, Thickness of 2 μm or more
- Resist Effing Ray 1 - At least 250A
/man bittern, for example, the thickness of the magnetic layer (3) (man)
-1.257zm based on the formula of 1,25 (77m)
This thickness is the upper limit when considering resolution.

In other words, when manufacturing a pattern of the upper r photoresist of the magnetic layer (3) only by ion beam etching in an argon gas atmosphere, from the viewpoint of etching accuracy based on the thickness of the photoresist, Although only a thin film magnetic head with a magnetic layer (3) of 2 μm or less can be manufactured, a pattern of upper part q (4) is formed on the magnetic layer (3) to form a mixed gas atmosphere layer (3). A thin film magnetic head having a thickness of 2 μm or more can be manufactured by etching with high accuracy.

Furthermore, since the lower layer (2) and JJ and the upper layer (4) are thin, an adhesive layer is formed, and the adhesive layer prevents the magnetic layer 7 (3) from peeling off.

Therefore, according to the above embodiment, the lower layer (2) and the upper layer (4) are formed from a reactive metal material and have a magnetic property! (3) is subjected to ion beam etching in an atmosphere of a mixed gas of argon gas and oxygen gas, so the magnetic layer (
Even when the thickness of the magnetic layer (3) is 2 μm or more, it can be etched with high precision.
) equipped! ', RJL film magnetic heads can be manufactured with high precision, and the lower layer (2) and upper layer (4) act as adhesive layers for the magnetic layer (3), preventing the magnetic layer (3) from peeling off. .

In the above embodiment, the magnetic layer (3) and the upper layer (4) are made of 1
Although the film was formed only once, even when a new magnetic layer and the upper layer are repeatedly formed on the upper layer (4), it is sufficient to perform ion beam etching on each magnetic layer in a mixed gas atmosphere. Of course, this method can be used to manufacture a thin film magnetic head having a plurality of magnetic layers.

Furthermore, it is of course possible to form the lower layer (2) and the upper layer (4) from a reactive metal other than titanium, and to form the magnetic layer (3) from a magnetic material other than permalloy. .

[Brief explanation of drawings]

1 to 4 are explanatory diagrams of an etching process in one embodiment of the method for manufacturing a thin film magnetic head of the present invention. (1)...Insulating substrate, (2)...Lower layer, (3)...
...magnetic layer, (4)...upper layer. Agent Patent Attorney Ryuta Fujita Department Figure 1 44 Tsuno Figure 5 No So 4 4

Claims (1)

[Claims] ■ In a method of manufacturing a thin film magnetic head having one or more magnetic layers having a thickness of 21 nm or more, a lower layer for adhesion and an end stop consisting of a reactive metal film such as titanium, chromium, aluminum, or molybdenum is used. an upper layer for adhesion and masking consisting of the magnetic layer and the reactive metal film is formed on top of the lower layer, and the upper layer is placed in an atmosphere of an inert gas such as argon gas. A method of manufacturing a thin film magnetic head, comprising performing ion beam etching and etching the magnetic layer in an atmosphere of a mixed gas of the inert gas and oxygen gas.