JPH04180550A - Formation of metallic layer for forming conductor pattern - Google Patents

Abstract

PURPOSE:To form a metallic layer which can automatically form conductor patterns with high dimensional accuracy by ionizing a rare gas in a hermetic chamber and bringing the ions into collision against a conductor metal to drive out its molecules, and adding an inert gas into the rare gas. CONSTITUTION:A substrate 1 consisting of ceramics, etc., and the conductor metal 2, such as Al, are disposed to face each other into the hermetic chamber 3. The rare gas 4, such as Ar, is introduced into this hermetic chamber 3, and after the inside of the chamber is vacuum evacuated to a prescribed pressure, a voltage is impressed between the conductor metal 2 and the wall surface to ionize the rare gas. The ionized rare gas 4 is brought into contact with the conductor metal 2 to drive out the molecules of the conductor metal 2 into the hermetic chamber 3 and to stick the molecules to the surface of a substrate 1, by which a metallic layer 5 for forming the conductor patterns is formed. An inert gas 6 such as N2 is added at 1 to 10% into the rare gas packed in the hermetic chamber 3. The surface of the above- mentioned metallic layer 5 is thereby formed as a uniform and fine satin surface. A resist is adhered with good stability to this metallic layer 5 and the conductor patterns of the high dimensional accuracy are formed by the automatic wet process etching.

Description

[Detailed Description of the Invention] [Summary] Regarding the method for forming a metal layer for forming a conductor pattern, it is possible to automate the wet etching process of the formed metal layer and improve the dimensional accuracy of the conductor pattern formed by wet etching. In order to achieve this, the substrate and the conductive metal are placed in a closed room, and the rare gas filled in the closed room is ionized and collides with the conductive metal, causing molecules of the conductive metal to be ejected into the closed room and attached to the surface of the substrate. In the method for forming a metal layer for forming a conductor pattern in which the metal layer for forming a conductor pattern is grown in vapor phase, an inert gas is added to the rare gas filled in the closed chamber.

FIELD OF THE INVENTION The present invention relates to a method for manufacturing a thin film multilayer substrate, and particularly to a method for forming a metal layer for forming a two-conductor pattern.

(Prior Art) As a method of forming a conductive pattern on the surface of a thin film multilayer substrate, for example, as shown in FIG. As shown in FIG. 5B, a resist 107 is attached to the portions of the metal layer 105 that are required as conductive patterns, and as shown in FIG.
There is a method of etching and removing unnecessary portions of the conductor pattern 108, and then peeling off the resist 107 to form the conductor pattern 108.

In the vapor phase growth method for forming the metal layer 105 on the substrate 101, for example, as shown in FIG. Reduce the pressure to a vacuum state S, to
After filling a closed room S with a rare gas 104 such as pure arcon (Ar) until the temperature reaches about 2 Pa, the rare gas 104 is ionized and collided with the conductive metal 1°2.
By forcing out the molecules from the closed room 1.3 and attaching them to the surface of the substrate 101, a metal layer 105 for forming a conductive pattern on the surface of the substrate 101 is grown by vapor phase growth.

[Problem to be solved by the invention]

By the way, a large number of metal crystals protrude from the surface of the metal layer 105 formed by vapor phase growth, as shown in the photograph shown in FIG. Moreover, the variation in distribution density is also very large.

For this reason, the state of adhesion of the resist l-107 to the surface of the metal layer 105 becomes unstable, and when the resist 107 is immersed in an etching solution for wet etching, the etching solution enters between the resist 107 and the metal layer 105, and the conductor pattern is damaged. The conductor pattern 108 may be eaten away or the resist 107 may be peeled off so that the conductor pattern 108 is not formed.

Furthermore, the instability of the adhesion state of the resist 1.7 to the surface of the MIX layer 105 makes the etching time unstable, and it is necessary to perform etching while checking the etching state for each substrate 101. Therefore, the etching process cannot be automated. There is also the problem of not being able to do so.

The present invention has been made in view of the above circumstances, and provides a conductor pattern forming method that can automate the wet etching process of the formed metal layer and improve the dimensional accuracy of the conductor pattern formed by wet etching. An object of the present invention is to provide a method for forming a metal layer for use in the present invention.

[Means to solve the problem]

For example, as shown in FIG. 1, the present invention provides a substrate 1,! : The conductor metal 2 is placed facing the closed room 3, and the rare gas 4 filled in the closed room 3 is ionized and collides with the conductor metal 2.
In order to achieve the above object, there is a method for forming a metal layer for forming a conductor pattern, in which molecules of the metal layer 5 for forming a conductor pattern are ejected into the closed room 3 and attached to the surface of the substrate 1 to form a metal layer 5 for forming a conductor pattern in a vapor phase. A measure is taken to add inert scum 6 to the rare gas 4 filling the closed chamber 2.

[For production]

In the present invention, the inert gas 6 mixed with the rare gas 1 and filled in the closed chamber 3 collides with the metal molecules pushed out into the closed chamber 3 and adheres to the surface of the substrate l. It is thought that the growth of metal crystals is suppressed by creating gaps at the grain boundaries of metal molecules that adhere to the surface of the metal, thereby making the metal crystal grain size finer. As a result, the surface of the substrate l becomes an averagely finely roughened surface, a so-called satin surface, and the adhesion to the resist becomes stable.

In the present invention, it is preferable that the amount of the inert gas 6 added to the rare gas 4 is about I to 10% of the rare gas 4. If the amount of the inert gas 6 added is less than 1%, the effect of improving the surface of the metal layer 5 by adding the inert gas 6 becomes weak, which is not preferable. In addition, the amount of inert gas 6 added is 10%.
If it exceeds 2, the structure of the metal layer 5 will become coarse and the electrical characteristics will be impaired, which is not preferable.

[Example] Hereinafter, a method for forming a metal layer for forming a conductor pattern according to an example of the present invention will be described with reference to FIGS. 1 to 3.

In this method, first, as shown in FIG. 1, the substrate 1 and the conductive metal 2 are placed facing the closed room 3 with their respective surfaces facing each other.

Although the substrate 1 is not particularly limited, a ceramic substrate formed by a conventional method was used here.

The conductor metal 2 may be any metal that can be used for conductor patterns of thin film multilayer substrates, such as aluminum (8L), copper (Cu), chromium (Cr), molybdenum (
Mo) etc. can be used. Here, aluminum was used, which allows the metal layer 5 to be grown in a vapor phase relatively quickly.

After this, the air in the closed room 3 is exhausted to about 10-'Pa, and the rare gas 4 and inert gas 6 are
About 0-'Pj; As a rare scum 4 filled until the
Argon (Ar), which is most commonly used, was used here.

As the inert gas 6, nitrogen (N2), carbon dioxide (C
Nitrogen (N2) was used here.

The amount of inert gas 6 added to rare gas 4 was varied in the range of 0 to 30% to find the optimum range.

After that, a predetermined voltage is applied between the wall surface of the closed chamber 3 on the substrate 1 side and the conductive metal 2 to ionize the rare gas 4, and cause it to collide with the conductive metal 2, causing metal molecules to jump out into the closed chamber 3. The metal layer 5 is attached to the surface of the substrate 1, and the metal layer 5 is vapor-phase grown on the surface of the substrate 1.

The surface of the metal layer 5 on the substrate 1 on which the metal layer 5 was formed in this manner was observed under a microscope, and the average grain size of the crystals appearing on the surface of the metal layer 5 was measured in relation to the concentration of the inert gas. When expressed in a graph, it becomes as shown in Fig. 2.

Further, after this, wet etching was performed according to the procedure shown in FIG. 5, and the formation state of the conductor pattern was observed.

When the surface of the metal layer 5 formed on the surface of the substrate 1 is observed under a microscope, as shown in FIG. 2, when the amount of inert gas 6 added is approximately 1% or more, the grain size of the crystal grains is 1.5%. It becomes smaller than 2 μm, and for example, as shown in the photograph shown in Figure 3,
It was observed that there was almost no variation in the grain size of the crystal grains, and moreover, it was a fine satin finish that was densely and evenly distributed.

The reason why the surface of the metal layer 5 becomes matte due to the addition of the inert gas 6 is that the inert gas 6 mixed with the rare gas 1 and filled in the closed room 3 is forced out into the closed room 3. It collides with metal molecules and adheres to the surface of the substrate l, creating gaps at the grain boundary surfaces of the metal molecules adhering to the surface of the substrate l, suppressing the growth of metal crystals, and making the metal crystal grain size finer. Seem.

As is clear from FIG. 2, when the amount of inert gas 6 added is less than about 1%, the grain size of the crystal grains on the surface of metal layer 5 increases. Also, there are variations in the ri diameter and distribution of crystal grains.

Furthermore, it was observed that the structure of the metal layer 5 was coarse in a range where the amount of inert gas 6 added exceeded about 10%. Therefore, when we investigated the electrical characteristics of this metal layer 5, we found that
It was confirmed that the electrical characteristics were significantly lower than when the amount of inert gas 6 added was about 10% or less.

Furthermore, in wet etching, when the amount of inert gas 6 added is less than about 1%, the resist peels off and the conductor pattern is eaten away, but when the amount is more than about 1%, the resist No peeling or erosion of the conductor pattern was found, and it was observed that the dimensional accuracy was sufficiently high.

In addition, the etching time is approximately 1% of the amount of inert gas 6 added.
It was confirmed that the above range corresponds to the size of the crystal grains on the surface of the metal layer 5. Therefore, by controlling the amount of the inert gas 6 added to control the size of the crystal grains on the surface of the metal layer 5, it is possible to control the size of the crystal grains on the surface of the metal layer 5.
Q Darkness can be drawn by 5, and the result is
It is no longer necessary to check the etching state of each substrate l, and it becomes possible to automate the wet etching process.

In the above embodiment, one metal layer 5 is formed on the base viI using one conductor metal 2, but two metal layers 5 are formed on the substrate 1 by sequentially using different conductor metals 2. More than one layer may be laminated. For example, titanium (
Ti) layer, a chrome layer on an aluminum layer, or an aluminum layer on a chrome layer.

〔Effect of the invention〕

As described above, in the present invention, when forming a metal layer on a substrate by vapor phase growth, by adding an inert gas to a rare gas, the surface of the metal layer is formed into fine crystals with almost no variation in grain size. It can be formed on a satin surface where grains are densely and evenly distributed, and the resist can be attached stably. As a result, a conductor pattern with high dimensional accuracy can be formed by wet etching.

In addition, the etching time of wet etching can be controlled by controlling the amount of inert scum added to the rare gas and controlling the particle size of crystal grains formed on the surface of the metal layer. Processes can be automated.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a method for forming a metal layer for forming a conductor pattern according to an embodiment of the present invention, and FIG. 2 is a diagram showing the relationship between the amount of inert gas added and the average grain size of crystal grains in the metal layer. FIG. 3 is a photograph showing the particle structure on the surface of the metal layer formed by the above example, and FIG. 4 is a graph showing the conventional method for forming a metal layer for forming a conductor pattern. FIG. 5 is an explanatory diagram of the wet etching procedure, and FIG. 6 is a photograph showing the structure of particles on the surface of a metal layer formed by a conventional method. In the figure, 1...Substrate, 2...Conductor metal, 3...Closed room, 4...Rare gas, 5...Metal layer, 6...Inert gas. Agent Patent Attorney Sada Igeta -, Ni 6 Inert gas (N2) Explanatory diagram of the metal layer forming method according to the present invention Figure 1 Particle size control showing the relationship between inert gas (N2 flow rate and average particle size) Characteristic diagram Diagram showing the structure of the particles on the surface of the metal layer formed by the engraving machine 11 of the drawing Fig. 4 An explanatory diagram of the conventional metal layer forming method Fig. 4 An explanatory diagram of the wet etching procedure Fig. 5 Fig. Figure 6 shows the structure of particles on the surface of a metal layer formed by the method. Figure 6. Procedural Amendment (Travel) March 1991, 2000 Patent Application No. 309885 2, Name of Invention Metal for Forming Conductive Patterns Layer Formation Method 3, Relationship with the Amendment Case Patent Applicant Address 1015 Kamiodanaka, Nakapage-ku, Yozaki City, Kanagawa Prefecture (5
22) Name: Fujitsu Limited Representative Yoshi Sekizawa 5 Date of amendment order: February 12, 1991 (old shipping)

Claims (1)

[Scope of Claims] [1] The substrate (1) and the conductive metal (2) are placed facing the closed chamber (3), and the rare gas (4) filled in the closed chamber (3) is ionized to form the conductive metal (2). A metal layer for forming a conductor pattern (5) is grown in a vapor phase by causing molecules of the conductor metal (2) to be ejected into a closed chamber (3) and attached to the surface of the substrate (1) to form a metal layer (5) for forming a conductor pattern. In the formation method, an inert gas (
6) A method for forming a metal layer for forming a conductor pattern, characterized by adding the following. [2] The method for forming a metal layer for forming a conductor pattern according to claim 1, wherein 1 to 10% of the inert gas (6) is added to 1 part of the rare gas (4). [3] The rare gas (4) is at least one of argon, helium, neon, krypton, and xenon,
The inert gas is at least one of nitrogen and carbon dioxide.
The method for forming a metal layer for forming a one-piece pattern according to claim 1 or 2, wherein the metal layer is a seed.