JPH0479008A - High aspect groove embedding method - Google Patents

Abstract

PURPOSE:To embed an insulating material into a high aspect groove without any void by applying a negative bias voltage only to this conductor when embedding the insulating material into the high aspect groove formed on a substrate by a bias sputtering method. CONSTITUTION:A negative bias voltage -V is applied to a conductor 10 on a substrate 1 and by executing sputtering to an insulating material molecules 12 while setting the substrate 1 at 0 potential the insulating material molecules 12 is accumulated on the exposing faces of the conductor 10 and an insulation pattern 2. Then, Ar<+> collides a simultaneously accumulated insulating material 4 so as to cut off one part of the surface of the insulating material 4. In such a case, the insulating material 4 accumulated on the upper or side surface of the conductor 10 is cut off by the collision of Ar<+> and the Ar<+> is not almost collided to an insulating material 4b accumulated on the bottom of a high aspect ratio 11. Therefore, speed for accumulating the insulating material 4 onto the bottom of the high aspect groove 11 is much higher than the other, and the high aspect groove 11 starts embedding the insulating material 4b from the bottom. Thus, the insulating material can be easily embedded into the high aspect groove while reducing the void.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a high aspect groove between conductors that are insulated on a substrate such as a thin film magnetic head and formed in a spiral shape or a cotton shape with a small pinch. This invention relates to a high aspect groove filling method in which an insulating material for insulating between conductors is filled using a bias sputtering method.

[Conventional technology]

With the increasing recording density of magnetic recording media such as magnetic tape,
Magnetic heads for recording and reproducing information on magnetic recording media are required to have increasingly high performance. The performance of this magnetic head is greatly affected by the number of turns of the coil that generates the magnetic field in the magnetic gap, the length of the magnetic path in the magnetic gap, etc., so the number of turns of the coil is increased and the length of the magnetic path is made shorter. Various efforts have been made to improve the performance of magnetic heads.

For example, Wi11ji coil or at
i! is a laminated film pattern of membrane cocoa. An example of the structure of a film magnetic head and an example of its manufacture will be described with reference to FIGS. 7 to 18. The thin-film magnetic head shown in FIGS. 7 and 8 has a first insulating pattern (2) made of aluminum oxide, etc., a thin-film coil pattern (3) made of copper, etc. on a ferrite ferromagnetic substrate (1), A second insulation pattern (4 degrees) such as aluminum, a thin film core pattern (5 degrees) such as Sendust
), and thin film coil extraction patterns (6) and (7) are partially overlapped and laminated, and a non-magnetic protection plate (9) is fixed thereon with low melting point glass (8). The thin film coil pattern (3) is formed by depositing a conductor (lO) such as copper in a spiral shape on the first insulating pattern (2) by dry etching or plating, and on top of this is formed a second insulating pattern (2). 4
°) is formed. The thin film core pattern (5) is formed in a pattern extending from the center of the coil of the thin film coil pattern (3) to the tip of the substrate (1), and its inner end (5a)
is connected to the substrate (1), the outer end (5b) is formed on the first insulating pattern (2), and a magnetic gap G is formed at this outer end by the thickness of the first insulating pattern (2). It is formed.

In order to improve the performance of the magnetic head, it is possible to increase the number of turns of the thin film coil pattern (3) to increase the strength of the generated magnetic field, or to increase the strength of the magnetic field formed by the thin film core pattern (5), the substrate (1), and the magnetic gap G. It is known to shorten the length of the magnetic path. The 'Vr# film coil pattern (3) shown in Figure 8 is a single layer, and the cross-sectional area determined by the current capacity of its conductor (10) remains unchanged, and the number of turns of the thin film coil pattern (3) remains m layers. If the number of magnetic heads is increased, the length of the thin film coil pattern (3) at the radius becomes larger, and the magnetic path becomes longer by that amount, making it difficult to improve the performance of the magnetic head. Furthermore, as a means of increasing the number of turns of the thin film coil pattern (3) without lengthening the magnetic path, it is known to form the thin film coil pattern (3) into a multilayer structure, as shown in FIG. 9, for example. There is. However, forming the thin film coil pattern (3) in multiple layers in this way requires a manufacturing process to form each thin film coil pattern (3) layer by layer, doubling the number of manufacturing steps for the magnetic head and increasing the manufacturing cost. There is a problem with the price increasing.

In addition, there is no need to lengthen the magnetic path (thin film coil pattern (3
) As shown in Fig. 10, another means of increasing the number of turns of the conductor (10) of the thin film coil pattern (3) is to shorten the width W and increase the height H without changing the cross-sectional area of the conductor (10) of the thin film coil pattern (3). ,
It is known that by reducing the pitch P of the conductors (10) by the amount that the width W is shortened, the number of conductors (10) that can be formed in a single layer in the radius portion of the length L of the thin film coil pattern (3) can be increased. It is being In this case, the aspect ratio, which is the ratio of the height H to the width W of the conductor (10), is increased, and the conductor (10)
The higher the aspect ratio of the depth H to the width P of the groove (11) formed between the conductor (10) and the @
(11) tends to have an increasingly high aspect ratio.

The high aspect ratio groove (11) is referred to as high aspect fi (11).
The method of embedding the insulating material of the second insulating pattern (4') in 1) will be explained.

The insulating material is often filled into the high aspect groove (11) using the Svanta method, which involves applying an insulating material, but this method is usually expensive, as shown in Figures 11 to 13. This is done as shown in . As shown in FIG. 11, a high aspect ratio conductor (lO) formed on the first insulating pattern (2) on the substrate (1) is set in a sputtering device. ) is sputtered with insulating material molecules (12) such as aluminum oxide. Then, the insulating material molecules (12) fly from various directions and are deposited on the exposed surfaces of the conductor (lO) and the first insulating pattern (2). In this case, the insulation molecule (12)
is not deposited to a uniform thickness over the entire exposed surface of the conductor (10) and the first insulating pattern (2), and approximately 270 insulating material molecules (12) are deposited on the corner C of the upper surface of the conductor (10). The conductor (
10) and the corner portion Co of the first insulating pattern (2), the insulating material molecules (12
) do not fly and are the most difficult to adhere to here.As a result, when the deposition of insulating material molecules (12) progresses to a certain extent, the conductor ( 1
0) The insulating material (4a) at the top corner swells into a canopy,
This prevents the insulating material molecules (12) from entering the high aspect ratio a (11). As the deposition of the insulating material molecules (12) further progresses, the insulating material bulges out like a canopy at the top corners of the two adjacent conductors (10) (10), as shown by the chain lines in FIG. This contact completely prevents the insulating material molecules (12) from flying into the Hyasbek)i (11). Then, a cavity (13) is formed in the insulating material (4b) filling the high aspect groove (11), and this cavity (13) remains even after the deposition of insulating material molecules (12) progresses. As shown in FIG. 13, irregularly shaped cavities (13) of various sizes were sometimes formed in the insulating material (4b) finally embedded in the high aspect groove (11). Such a sky m (13) is high aspect I
l! The higher the aspect ratio of (11), the more conspicuous the occurrence, which may cause poor insulation between conductors or when forming the Wi film cocoa pattern 5) on the second insulation pattern (4'). This deteriorates the heat resistance of the conductor (10) against heat, causing a decrease in the yield of manufacturing magnetic heads.

Therefore, recently, as a method of embedding the insulating material (4) in the high aspect m (11) with fewer cavities, when sputtering the insulating material molecules (12), the substrate (1
) A bias sputtering method has been developed and implemented in which a negative bias voltage is applied across the substrate (1) and inert ions, such as argon ions (hereinafter referred to as Ar+), are bombarded towards the conductor (10) of the substrate (1). ing. By using this bias sputtering method, the high aspect ratio m (11) is coated with the insulating material (4).
) will be explained with reference to FIGS. 14 to 16.

As shown in FIG. 14, when a substrate (1) with a first insulating pattern (2) and a conductor (10) formed thereon is placed in a sputtering apparatus, the substrate (1) containing the conductor (10) A constant negative bias voltage -■ is applied throughout. In this state, when insulating material molecules (12) are sputtered and Ar+ is supplied to the sputtering device at the same time, Ar+ is applied to the conductor (10) and the first insulating pattern at a negative bias voltage of −■ between the substrate (1) and the conductor (10). (2) The exposed surface is collided with from various directions. Ar+ has almost no reactivity,
Only the insulating material molecules (12) are deposited on the exposed surfaces of the conductor (10) and the first insulating pattern (2) without being deposited on the exposed surfaces of the conductor (lO) or the first insulating pattern (2). , Ar+
impinges on the deposited insulation (4). A part of the deposited insulating material (4) flies out due to the collision energy of this Ar+, and the surface of the insulating material (4) is scraped.

Like the insulating material molecules (12), Ar+ most easily flies to the top corner C1 of the conductor (1o), and removes the most amount of the insulating material (4) deposited at the top corner of the conductor (10). Therefore, if the rate at which the insulating material molecules (12) are removed by Ar+ is set to be smaller than the rate at which the insulating material molecules (12) are deposited, the conductor (10) and the first
The insulating material (4) is deposited on the exposed surface of the insulating pattern (2) in a relatively average manner. In other words, the deposition of the insulating material (4) and the insulating material scraping due to Ar'' collision proceed simultaneously, but if a small amount of the insulating material (4) is deposited first, as shown by the chain line in FIG. ” If you cause a collision,
The insulating material (4a) that bulges like an eave at the top corner C1 of the conductor (10) is the most heavily shaved off by the Ar+ collision, and its thickness is the same as that of the others, making it the largest part of the entire insulating material (4). The thickness is made uniform.The same thing occurs when insulating material deposition and Ar+ collision proceed simultaneously, resulting in high aspect fi (
The insulating material (4) is embedded relatively well in the high aspect groove (11), and as shown in FIG. 16, no cavity is left in the insulating material (4b) embedded in the high aspect groove (11).

[Problem to be solved by the invention]

By the way, when embedding the insulating material (4) in the high aspect groove (11) using the bias sputtering method described above, Ar+ scrapes the insulating material (4) deposited on the top and side surfaces of the conductor (10), and also removes the first insulating material (4). The insulating material (4b) deposited on the bottom of the high aspect ratio m (11) is also removed on the exposed surface of the pattern (2). Therefore, the conductor (10) and the high aspect groove (1
The higher the high aspect ratio (1) is, the more difficult it becomes to fill the high aspect groove (11) with the insulating material (4) without any voids, as will be described later.

For example, as shown in FIG. 17, a high aspect groove in a high aspect ratio conductor (1o) in which the width W of the conductor (10) and the groove width P are several μm, and the height H is approximately 5 μm or more. When the insulating material (4) was embedded in the insulating material (11) by bias sputtering, a cavity (13) was sometimes formed in the embedded insulating material (4), as shown in FIG. In other words, there is not much difference between the deposition rate of the insulating material (4b) deposited from the bottom of the high aspect groove (11) and the deposition rate of the insulating material (4a) deposited on the top corner C1 and side surfaces of the conductor (10). , once the insulation material deposition has progressed to a certain extent, ! @17
As shown by the chain line in the figure, before the insulation material (4b) deposited from the bottom of the high aspect groove (11) has grown sufficiently, the insulation material deposited on the upper surface corner C5 of the adjacent conductor (10) (10) When the materials came into contact with each other, a cavity (13) was formed directly beneath it, and this sometimes remained as it was. Such cavities (13) are more numerous and larger as the high aspect ratio of high aspect fi (11) increases, and this causes high aspect jlli (11)
This makes it difficult to further increase the aspect ratio of the conductor (10), making it difficult to further improve the performance of the thin film magnetic head.

Therefore, an object of the present invention is to provide a high aspect a filling method using a bias sputtering method that can reliably fill an insulating material into a high aspect groove without voids even if the high aspect ratio of the high aspect groove becomes high. Our goal is to provide the following.

[Means to solve the problem]

The technical means of the present invention to achieve the above object is that when an insulating material is embedded in a high aspect groove with a small groove width between conductors formed insulated on a substrate by a bias sputtering method, a negative bias is applied only to the conductor. It is to apply a voltage.

[Effect]

A negative bias voltage is applied only to the conductors formed insulated on the substrate, and insulating material molecules are deposited by bias sputtering in the high aspect groove between the conductors, and inert ions are applied to the deposited insulating material. For example, when Ar+ collides, A
r+ flies to the conductor to which negative bias voltage is applied,
It only hits the insulation material that is being deposited on the conductor, shaving off some of it. Therefore, the rate at which the insulating material deposited at the bottom of the high-aspect groove is scraped away by Ar+ collisions is significantly reduced.
The rate of deposition of insulation material from the bottom of the high-aspect trench increases, the speed at which the insulation material is filled into the high-aspect trench becomes faster, and the rate of formation of cavities in the buried insulation material decreases. This enables the aspect groove to have an even higher aspect ratio.

〔Example〕

Hereinafter, specific embodiments of the present invention will be described with reference to FIGS. 1 to 6.

This figure shows high aspect grooves (11) between conductors (10) formed with a high aspect ratio on the first insulating pattern (2) of the substrate (1) in the thin film magnetic head shown in FIG. ) is used to explain the method of the present invention in which an insulating material (4) such as aluminum oxide is embedded in the substrate by bias sputtering.

As shown in FIG. 1, the present invention applies a negative bias voltage -■ only to the conductor (1o) when sputtering insulating material molecules (12) onto the conductor (1o) on the substrate (1) using a sputtering device. The method is characterized in that inert ions such as Ar+ are caused to collide with the substrate (1). The negative bias voltage -■ may be applied to the conductor (1o) through the thin film coil lead-out patterns (6) and (7) shown in FIG.

A negative bias voltage -■ is applied to the conductor (10), and the substrate (1
) when the insulating material molecules (12) are sputtered at zero potential, the conductor (10) and the first
Insulating material molecules (12) fly and deposit on the exposed surface of the insulating pattern (2). At the same time as this deposition, Ar'' flies and collides with the deposited insulating material (4), and the insulating material (4)
scrape a part of the surface. Here, the flying direction of Ar+ is almost determined in the direction of the conductor (10) to which the negative bias voltage V is applied, and the insulating material (4) deposited on the top and side surfaces of the conductor (10)
is scraped by Ar+ collisions, and Ar+ collisions on the insulating material (4b) deposited at the bottom of the high aspect groove (11) are almost eliminated. Therefore, the deposition rate of the insulating material (4b) at the bottom of the high aspect groove a (11) becomes much faster than in the other regions, and the insulating material (4b) is embedded in the high aspect groove (11) from the bottom.

The above operation of embedding insulating material will be explained using an example in which sputtering of insulating material molecules (12) and Ar''jfl bombardment are performed separately, as shown in FIGS. 5 and 6. As shown in Figure 5, by sputtering only the insulating material molecules (12), the insulating material (4) is deposited on the exposed surfaces of the conductor (10) and the first insulating pattern (2). (1o) This is often performed at the upper surface corner C1.

next! @6 As shown in Figure 6, when a negative bias voltage -■ is applied to the conductor (10) and A r ” fi thrust is performed,
Ar+ cuts only the insulating material (4) deposited on the conductor (10) to make the thickness average, and the insulating material (4b) deposited at the bottom of the high aspect groove (11) remains as it is. When such molecular sputtering and A r ” collision are performed simultaneously, the insulating material (4b) grows from the bottom of the high aspect groove (11), as shown in FIGS. 3 and 4. ,
The insulating material (4b) is embedded in the high aspect fi (11) without any cavity.

In the above embodiment, the negative bias voltage is described as part of the voltage, but it may be applied in multiple stages such as one constant voltage of -100 volts, or two constant voltages of -100 volts, -150 volts, etc. By setting, it is possible to control the film condition of the insulating material (4) (change the surface and thickness).

Furthermore, the present invention is not limited to a method of embedding an insulating material into a high aspect groove formed between conductors of a thin film coil pattern in a thin film magnetic head, but is also applicable to a method of embedding an insulating material into a high aspect groove formed between conductors of a thin film coil pattern in a thin film magnetic head, and is also applicable to high aspect ratio between conductors for wiring in LSI, where high density wiring is required. It can also be effectively applied to a method of embedding an insulating material into a groove or a high aspect groove formed by linear etching or the like in a wide thin film conductor formed on a printed circuit board or the like.

〔Effect of the invention〕

According to the present invention, when an insulating material is sputtered and deposited in a high aspect groove between conductors, only the insulating material deposited on the conductor is removed by the collision of inert ions such as Ar+ due to the negative bias voltage of the conductor. The insulation material deposited at the bottom of the high-aspect groove is A
Since the deposition continues with almost no r+ collisions, the insulating material can be easily filled into the high aspect groove with fewer cavities, making it possible to increase the aspect ratio of the high aspect groove. If the method of this invention is applied to the technology of filling insulating material between the conductors of the thin-film coil pattern of a thin-film magnetic head, it will be possible to make the conductor of the thin-film coil even higher in aspect ratio, and it will be effective in improving the performance of the thin-film magnetic head. be.

[Brief explanation of drawings]

1 to 6 are for explaining the method of the present invention, and FIGS. 1 to 4 are partial cross-sectional views of the substrate in various operating states when embedding an insulating material in a high aspect groove, and FIG. 6 and 6 are partial cross-sectional views of a substrate used for reference in explaining the method of the present invention. FIG. 7 is a partial plan view of the thin-film magnetic head including a partially omitted part, FIG. 8 is an enlarged cross-sectional view taken along line A-A in FIG. 7, and FIG.
10 and 10 are partial cross-sectional views showing examples of partial modifications of the thin film magnetic head shown in FIG. FIG. (1) ---One board, (4) (4b) ---
Insulating material, (10) - conductor, (11) - high aspect groove. Figure 1 No. 2111 Patent issued by Kansai NEC Co., Ltd.
Rijin Gangwon Province I Figure 3 4b Figure 4 is 11 Figure 13'l'4'1 1

Claims (1)

[Claims] (1) A high aspect method characterized by applying a negative bias voltage only to the conductor when filling an insulating material into a high aspect groove having a small groove width between conductors formed insulated on a substrate by a bias sputtering method. Groove filling method.