JP2709387B2 - Method for manufacturing thin-film magnetic head - Google Patents

Description

The present invention relates to a thin-film magnetic head in which at least a magnetic layer, a coil conductor layer, an insulating layer, and a protective layer are formed in a predetermined shape on a substrate by film formation and etching. And a method for producing the same. (Prior Art) A thin film magnetic head is, for example, as shown in FIG.
A lower magnetic layer 2, an insulating layer 3, and a patterned coil conductor layer 5 are sequentially laminated on a substrate 1. Also,
The lower magnetic layer 2 is partially exposed to form a magnetic gap surface, and a magnetic gap layer is usually provided on the gap surface. In a multilayer thin film magnetic head,
An upper coil conductor layer, an upper insulating layer, and an upper magnetic layer (all not shown) on the coil conductor layer 5 via an intermediate insulating layer.
Are sequentially laminated. Further, the thin-film magnetic head is provided with an adhesion layer between the respective layers in order to increase the adhesion between the above-described layers and prevent peeling. In FIG. 1, the adhesion layer is formed between the lower insulating layer 3 and the lower coil conductor layer 5 (reference numeral 4). In the multilayer thin-film magnetic head, the adhesion layer is provided between the coil conductor layer 5 and the intermediate insulating layer, between the intermediate insulating layer and the upper coil conductor layer, and between the upper coil conductor layer and the upper insulating layer. Are provided in the same manner. These adhesion layers are generally formed of Ti, and the adhesion layers are hereinafter referred to as Ti layers in this specification. (Problems to be Solved by the Invention) However, the above-mentioned Ti layer induced the following drawbacks in the head manufacturing process. That is, in the production of the thin film head, in FIG. 1, first, a lower magnetic layer 2, an insulating layer 3, a Ti layer 4, a coil conductor layer 5 and a Ti layer 6 are sequentially laminated on a substrate 1, and illustration thereof is omitted. The exposed photoresist is applied through a mask (not shown), and the unexposed portion is subjected to ion milling to remove a portion (hatched portion in the drawing) of the coil conductor layer 5. Next, the remaining photoresist is removed to remove the coil conductor layer 5.
Is completed. Here, the Ti layer is formed at a normal temperature of the substrate in order to improve the flatness of the surface. This is because the Ti atoms jumping out of the target are fixed rapidly on the substrate at room temperature from the high-temperature gas-phase state and are formed with low mobility on the substrate.As a result, the Ti layer is composed of very fine crystal grains. It depends. However, the microcrystalline Ti in the Ti layer is in a non-equilibrium state, and when exposed to a high temperature, it grows into coarse crystal grains, or the Ti forms a metal (eg, copper) that forms the coil conductor layer. It is easy to form an intermetallic compound to form a coarse crystal and is in an unstable state. When ion milling is performed for patterning the coil conductor layer 5 in such a situation, first, ions collide with the uppermost Ti layer 6 and the surface temperature of the Ti layer 6 rises, whereby the Ti particles 6 Coarsening occurs, and irregularities are formed on the surface layer. Since the etching rate by ion milling can be considered to be constant, the thickness of the Ti layer 6 is reduced while maintaining the shape of the irregularities substantially as the ion milling proceeds, and in some cases increasing the amount of irregularities. . When the ion milling proceeds to the boundary surface between the Ti layer 6 and the coil conductor layer 5, the irregularities of the Ti layer 6 are transferred to the surface of the coil conductor layer 5 as it is.
Are also milled along the irregularities. Then, the irregularities of the coil layer 5 are similarly transferred to the lower Ti layer 4 and finally to the lower insulating layer 3. In the case of a multilayer thin-film magnetic head, after patterning of the coil conductor layer 5, patterning of the upper coil conductor layer is also performed by a similar photolithography process. Therefore, when patterning the upper coil conductor layer, the Ti particles in the Ti layer are coarsened. Occurs, and the irregularities are sequentially transferred to the lower layer. The lower coil conductor layer 5 (and upper coil conductor layer)
After the completion of the patterning, each layer is finally removed by taper etching to expose the lower magnetic layer 2 and form a magnetic gap surface. At this time, the upper insulating layer 3 is formed. Since the irregularities described above are formed, the irregularities are transferred to the magnetic gap surface by this taper etching. The unevenness of the magnetic gap surface is a factor that deteriorates the magnetic conversion characteristics of the thin-film magnetic head. The present invention has been made in view of the above circumstances, and it is possible to prevent irregularities generated in a Ti layer from being transferred to a magnetic gap surface during patterning of a coil conductor layer, thereby obtaining a thin film capable of obtaining good electromagnetic conversion characteristics. An object of the present invention is to provide a method for manufacturing a magnetic head. (Means and Actions for Solving the Problems) The present inventor conducted experiments by changing the film forming conditions of the Ti layer in various ways, and found that the irregularities change depending on the substrate temperature during film formation. I found it. That is, the object of the present invention is to provide a method of manufacturing a thin-film magnetic head in which at least a magnetic layer, a coil conductor layer, an insulating layer, and a protective layer are formed on a substrate and formed into a predetermined shape by etching. A Ti layer disposed between the conductive layer and the two layers in close contact with each other has a substrate temperature of 100 ° C.
This is achieved by a method for manufacturing a thin-film magnetic head, wherein a film is formed by a sputtering method in a temperature range of up to 200 ° C. As described above, when a part of the coil conductor layer is removed by ion milling, irregularities are transferred to the surface of the insulating layer thereunder.
By forming the film at a temperature of about 200 ° C., the formation of the unevenness can be reduced. This is because the substrate temperature during the formation of the Ti layer was increased, so that even after the
It is considered that the mobility of Ti atoms is high and stable equilibrium crystal grains are formed. Therefore, the surface properties immediately after the formation of the Ti layer are slightly inferior to those when the film is formed by setting the substrate temperature to normal temperature, that is, the amount of unevenness is large, but in a homogeneous and thermally stable crystalline state. For this reason, even when the coil conductor layer is exposed to a high temperature during film formation or ion milling, the coarsening of crystal grains is suppressed, and as a result, the transfer of irregularities to the magnetic gap surface is suppressed. Examples of the substrate material of the thin-film magnetic head manufactured according to the present invention include magnetic ferrite, non-magnetic ferrite, sapphire, and ceramic. (Example) CoNb on a fallite substrate by RF sputtering method
A lower magnetic layer was formed by depositing a 15 μm Zr alloy ferromagnetic material. Next, 2 μm of SiO ₂ was formed on the lower magnetic layer by sputtering.
The nonmagnetic insulating layer was formed by adhesion. A Ti layer serving as an adhesion layer was sputtered thereon so as to have a thickness of 0.05 μm. The argon pressure during sputtering was 0.2 Pa, the input power was 1 kW, and the substrate temperature was varied. The substrate temperature is the temperature of the substrate holder because accurate measurement and control are difficult. A copper conductor serving as a winding is deposited on the Ti layer thus obtained by sputtering, and a Ti layer is formed thereon again, and then a photoresist is applied, and the conductor is ion-milled to form a patterned coil. A conductor layer was formed. During the process, after forming a Ti layer under various substrate temperatures,
The results of measurement of the amount of irregularities on the surface of the conductor formed on the Ti layer and the amount of irregularities transferred to the insulating layer after ion-milling the conductor are shown in the table below. As is clear from the above table, when the substrate temperature is set to 100 ° C. or higher and the Ti layer is formed, a relatively large value of 0.03 μm to 0.05 μm is observed as the unevenness after the deposition of the Cu conductor. However, the amount of unevenness transferred to the insulating layer after ion milling was as small as 0.01 μm or less. On the other hand, when the Ti layer is formed at a substrate temperature of room temperature, the amount of unevenness after the formation of the conductor is as small as 0.01 μm or less, but the amount of unevenness transferred to the insulating layer thereafter is opposite.
A large value of 0.2 μm or more was observed. After the coil conductor layer is formed, the thin-film magnetic head according to the present invention forms the non-magnetic insulating layer again as before, and further magnetically joins the lower magnetic layer on the non-magnetic insulating layer at the gap. As described above, the upper magnetic layer of the CoNbZr alloy was formed to a thickness of 15 μm by a sputtering method, and then a protective layer was provided. (Effects of the Invention) As described above, according to the method for manufacturing a thin film magnetic head of the present invention, the coil conductor layer is formed by forming Ti as an adhesion layer at a substrate temperature of 100 ° C to 200 ° C. It is possible to manufacture a thin-film magnetic head having good electromagnetic conversion characteristics by eliminating the transfer of irregularities to the magnetic gap surface during patterning.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a part of a thin-film magnetic head and is a view for explaining a state when a coil conductor layer is patterned. 1: substrate, 2: lower magnetic layer, 3: non-magnetic insulating layer, 4, 6: Ti layer, 5:
Coil conductor layer

Claims (1)

(57) [Claims] In a method for manufacturing a thin-film magnetic head in which at least a magnetic layer, a coil conductor layer, an insulating layer, and a protective layer are formed and formed into a predetermined shape on a substrate by disposing the film between the insulating layer and the coil conductor layer, A method for manufacturing a thin-film magnetic head, wherein the Ti layer for adhering the two layers is formed by a sputtering method at a substrate temperature of 100 ° C to 200 ° C.