JPS5974608A - Formation of wiring structure - Google Patents

Abstract

PURPOSE:To obtain a flat insulation layer by a method wherein a conductor layer of a prescribed pattern is formed on a substrate and the 1st insulation layer of approximately the same thickness as the conductor layer is formed on the part of the substrate other than the pattern of the conductor layer and then an insulation layer for the prescribed pattern is formed. CONSTITUTION:The conductor layer 5 of a prescribed pattern is formed on a substrate 4 and an insulation layer 6 of approximately the same thickness as the conductor layer 5 is formed between the conductor pattern 5 and 5. After the difference in level between the conductor pattern 5 and 5 is thus filled, an insulation layer 7 is formed and a flat insulation layer is obtained. Moreover, a conductor layer 5 and an insulation layer 6 can be formed on the insulation layer 7 and an insulation layer can be formed on them. By laminating successively like this, multi-layer conductor can be formed. By the precision leveling like this, photo-lithography technology can be used and a magnetic circuit which is especially useful in case of composing a thin film magnetic head.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a method for forming a wiring structure applied to coil wiring of a thin film magnetic head, etc., and a forming method for flattening an insulating layer of this wiring structure. Regarding.

[Prior art]

Planarization of the insulating layer of the wiring structure has a great influence on forming a pattern on the surface of this insulating layer.

For example, in the case of a magnetic head, this has a significant impact on its performance.

Particularly in thin film processes, as patterns become finer, highly accurate planarization of insulating layers of wiring structures is required, which has become a major technical issue.

For example, regarding magnetic heads manufactured using thin film technology, conventionally organic resins are used for insulation between the conductor coil and the magnetic material and between conductors, but these insulating layers can be flattened. It was difficult to do so.

For example, a case where a polyimide resin is used as the organic resin will be described in more detail with reference to FIG.

In the figure, a wiring 2 is formed on a substrate l, and this wiring 2.
A wiring structure was formed by applying a polyimide insulating layer 3 thereon.

When a wiring structure is manufactured by such a method, the polyimide insulating layer 3 covering the wiring 2 is formed on the wiring 2 and between the wirings 2 due to the step difference in the wiring 2 formed on the substrate 1. There was a drawback that the height VC was not the same as that on the substrate 1, and the surface of the polyimide insulating layer 3 was not undulated.

For example, when a magnetic film is formed on this insulating layer, the magnetic film itself permanently undulates, resulting in a decrease in magnetic properties.

[Purpose of the invention]

The present invention aims to solve the above-mentioned conventional drawbacks and provide a method for forming a wiring structure that can obtain a flat insulating layer.

[Summary of the invention]

That is, in the present invention, the insulating layer is divided into a first insulating layer and a second insulating layer, and a first P3 green layer is provided between the conductors formed on the substrate to eliminate the difference in level between the conductors. A second insulating layer is formed on the second insulating layer and flattened. First, a conductor layer having a 75r constant pattern is formed on the substrate, and then a second insulating layer is formed on the substrate other than the pattern of this conductor layer. A first insulating layer with a thickness similar to that of the conductor layer is formed, and then a second insulating layer is formed on the conductor layer and the first insulating layer to flatten the surface of the insulating layer. It is something to do.

Further, a conductor layer and a first insulating layer are formed on the second insulating layer by the same method, and a second insulating layer is further formed on top of the second insulating layer, and in this way, the second insulating layer, the conductor layer, and the first insulating layer are formed. It is characterized by forming a plurality of conductor layers by sequentially laminating the conductor layers.

[Embodiments of the invention]

The details of a simple embodiment of the present invention will be explained below. First, the outline of the embodiment will be explained using FIG. 2.

In the figure, a conductor layer 5 having a predetermined pattern is formed on a substrate 4. Next, a first insulating layer 6 having a similar thickness is formed between the conductors JvI5 and 5.

After eliminating the step between the conductor layers 5 and 5 in this way,
By forming the second insulating layer 7, a flat insulating layer can be formed.

Furthermore, a plurality of conductor layers can be formed by sequentially stacking the conductor layer 5, the first insulating layer 6, and the second insulating layer 7 on the insulating layer 7.

The details will be explained in more detail below. In FIG. 2, a conductive layer is deposited on a substrate 4 by vapor deposition or sputtering, and a predetermined pattern of a conductive layer 5 is formed by photoetching (FIG. 2(a)). Next, an organic resin is applied and heat-treated to form a film to the same thickness as the conductor layer 5, and then it is embedded in the gap between the conductor layers 5 using a photo-etching technique as shown in the figure. Like, 1st
An insulating layer 6 is formed. After forming the conductor layer 5 and the first insulating layer 6 on the substrate 4 in this way, the second insulating layer 7 is formed as shown in FIG.

In this way, a wiring structure with a flattened single-layer conductor pattern is formed.

Next V? - When manufacturing a wiring structure with a flattened conductor pattern of multiple layers, the second insulating layer 7 shown in FIG.
A conductor layer 5 as shown in FIG.
This is done by repeatedly stacking layers IFj times.

The operation of this embodiment configured as above will be explained next.

By embedding the second insulating layer 6 between the conductor layers 5 deposited in a predetermined turn on the substrate 4, the difference in level between the conductors N5 is eliminated, and the conductor layer deposited on the substrate 4 and the first The common plane of the insulating layer 6 is flattened. By forming the second insulating layer 7 on the common plane of the conductor layer 5 and the first insulating layer 6 which have been flattened in this way, the common plane is flattened. This results in a smooth insulating surface.

Further, on this insulating surface (the surface of the second insulating layer 7), a conductor layer 5,
By repeatedly laminating the first insulating layer 6 and the second insulating layer 7 in the same manner, a wiring structure in which a plurality of layers of conductive patterns are planarized is obtained.

Examples of actual implementation are shown below.

Example 1: Regarding a wiring structure in which a single-layer conductor pattern was flattened, the same effect was obtained by depositing a conductor layer with a thickness of about 2 μm over the entire curve of the substrate 4 by vapor deposition and sputtering). Line width 10μm using photoetching technique
A wiring pattern with an S line interval of 8 μm was formed. (The same effect was obtained even if this wiring pattern was made using plating techniques.) Next, an organic resin was applied and heat treated to form a film to the same thickness as the wiring pattern layer, and then photo-etched. A first insulating layer of an organic resin was formed to fill the gap between the wiring lines using a technique. Finally, a second insulating layer having a layer thickness of about 2 μm was formed. It was confirmed that the upper surface of the second insulating layer formed in this manner had a good flat surface with a waviness height of 0.2 μm or less.

Example 2: Regarding the formation of a conductor coil for a thin film magnetic head, as shown in FIG. 3, an inorganic insulating film (for example, At205) was sputtered over the entire surface of a ceramic substrate 8 to form a flat base film 9. Next, permalloy with a thickness of 2 μm was deposited on this base film 9 by sputtering, and patterned by a photoetching technique to form a lower magnetic layer 10. Next, as a gear spacer, an inorganic insulating material (for example, At203) with a thickness of about J .mu.m was deposited by sputtering and patterned by a photoetching technique. On top of that xoooA's Cr r 1.5 Jim's C
The same effect was obtained by sputtering CrF vapor deposition at 1000 A, but the first
A layered conductor coil 12 was formed.

Next Kg photosensitive polyimide precursor composition (%
408) using photolithography technique to form a pattern so as to fit into the gap between the coils,
A first insulating layer 13 was used. The thickness of the first insulating layer 13 at this time was about 1.7 μm, which was about the same as that of the first layer conductor coil 12. Further, using the above photosensitive polyimide precursor composition, a second insulating layer 14 having a thickness of about 1.5 μm was patterned on the first layer conductor coil 12 and the first insulating layer 13 by photolithography technique. .

Next, as with the first layer conductor coil 12, a thickness of about 1.7 μm is applied.
The second layer conductor coil 15, the third insulating layer 16 in the same manner as the first insulating layer 13, and the fourth insulating layer 17 in the same manner as the second insulating layer 14 are successively formed.

Note that the thicknesses of the third insulating layer 16 and the fourth insulating layer 17 at this time were each approximately 1.7 μm + 1.5 μm.

Permalloy with a thickness of 2 μm was deposited on the entire surface of the substrate constructed as described above by sputtering, and patterned by photoetching to form the upper magnetic layer 18.

The upper surface of the fourth insulating layer 17 obtained by molding in this manner had a waviness height of 0.2 μm or less, and the magnetic properties of the magnetic head were satisfactory.

Example 3: Another example of forming a conductor coil for a thin film magnetic head will be described with reference to FIG. A base film 9 is formed on a substrate 8 in the same manner as in the second embodiment. A lower magnetic layer 10 having a thickness of about 2 μm is formed on this base film using a plating technique.

Next, an inorganic insulating film 11 having a thickness of about 11 m is formed as a cap baser in the same manner as in the second embodiment.

Subsequently, a five-layer single-layer conductor coil 12 having a line width of LO μm and a line spacing of 5 lines is formed by plating. An insulating layer 13 having a thickness of about 1.7 μm is formed by photolithography so as to exactly fill the gap between the conductor coils 12 in the first layer. This first insulating layer contains AZ-1350
J (manufactured by Shipley) was used. Then the same (AZ-1
Approximately 1.5μ was deposited on the first layer conductor coil 12 and first insulating layer 13 by photolithography using 350J.
A second insulating layer 14 having a thickness of m was patterned. Furthermore, the first
A second thick body coil 15 with a thickness of about 1.7 μm in the same manner as the layer conductor coil 12, and a third insulating layer 16 with a thickness of about 1.7 μm in the same manner as the first insulating layer 13, Furthermore, in the same manner as the second insulating layer 14, a fourth insulating layer 17 having a thickness of about 1.5 μm was formed. Finally, the upper magnetic layer 18 having a thickness of about 2 μm was formed using a plating technique.

The undulation height of the upper surface of the fourth insulating layer 17 configured as described above is 0.2 μm or less, and the magnetic properties of the magnetic head are as follows.
It was satisfying.

Incidentally, in the prior art (FIG. 1), a conductor with a thickness of about 2 μm is deposited by vapor deposition on the entire surface of a substrate 1, and a wiring pattern with a line width of 10 μm and a line spacing of 8 μm is formed using a photoetching technique. Next, an organic resin is applied to this wiring pattern and heat treated to form a film with the same thickness as the conductor layer.
When the insulating layer 3 was formed, the waviness height of the insulating layer 3 was 0.
．． It was 5 μm or more, and the waviness height was about 2.5 times or more compared to Example 1.

〔Effect of the invention〕

As detailed above, according to the method of the present invention, the insulating layer is
The first insulating layer is divided into two, an insulating layer and a second insulating layer, and the first insulating layer is buried between the conductor layers formed on the substrate, eliminating the step between the conductor layers, and forming the second insulating layer on top of the first insulating layer. As a result, it was possible to create a wiring structure in which the conductor pattern was flattened with high precision. This high-precision planarization not only makes it advantageous to use photolithography to form even finer patterns, but also makes it possible to manufacture three-dimensional wiring structures with multiple layers, especially when constructing a thin-film magnetic head. Since unnecessary unevenness is not created on the upper magnetic layer, it is effective in terms of magnetic circuits and has excellent effects.

[Brief explanation of drawings]

FIG. 1 shows a conventional example and is a sectional view of a wiring structure having a single layer of conductors. FIG. 2 shows an embodiment of the present invention,
FIG. 3 is a diagram illustrating a method for forming a wiring structure using a single-layer conductor as an example. FIG. 3 shows another embodiment of the present invention, and is a cross-sectional view of a piping structure having multiple layers of conductors, taking a thin film magnetic head as an example. 4... Substrate, 5... Conductor layer, 6... First insulating layer,
7... Second insulating layer. Agent Tadashi Akimoto, Patent Attorney Figure 1, Figure 2 (0) 5 Continuation of Figure 3, Page 1 0 Inventor Yokononaka, Hitachi, Ltd. Production Technology Laboratory, 292 Yoshida-cho, Totsuka-ku, Yokohama 0 Author: Shun Kuwazuka, Hitachi, Ltd., Odawara Factory, 2880 Kokufutsu, Odawara City

Claims (1)

[Claims] 1. A conductor layer having a constant pattern of VCJ5T is formed on a substrate, a first insulating layer having a layer thickness comparable to that of the conductor layer is formed on the substrate other than the pattern of the conductor, and then A method for forming a wiring structure, characterized in that a second insulating layer having a predetermined pattern is formed on the conductor layer and the first insulating layer to form a single-layer conductor layer. 2. A wiring structure characterized in that in the first insulating layer and the second insulating layer according to claim 1, at least one of these insulating layers is made of a photosensitive material and is formed by photolithography technology. molding method. 3. In the first insulation layer and the second insulation layer according to claim 1, the P edge layer of at least one of these insulation layers is made of a photosensitive polyimide precursor composition and is formed by photolithography technology. A method for forming a wiring structure. 4. Forming a conductor layer with a predetermined pattern on the substrate,
A first insulating layer having a layer thickness comparable to that of the four-body layer is formed on the substrate other than the pattern of the conductor layer, and then a second insulating layer having a predetermined pattern is formed on the conductor layer and the first insulating layer. a conductive layer and a first insulating layer, further having a predetermined pattern on the second insulating layer. and a method for forming a wiring structure in which a second insulating layer is repeatedly laminated to form a plurality of conductor layers. 5. Wiring characterized in that in the first insulating layer and the second insulating layer according to claim 4, at least one of these insulating layers is made of a photosensitive material and is formed by photophosphorography technology. How to form the structure. 6. In the first insulating layer and the second insulating layer according to claim 4, at least one of these insulating layers is made of a photosensitive polyimide precursor composition, and is formed by -photography technology. A method for forming a wiring structure.