JPS60247989A - Method of forming electrode pattern - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of forming an N electrode pattern of an electronic component by etching.

(Description of prior art) Electronic components, such as semiconductor devices, have electrodes (including wiring).
is formed, and as this electrode, the N electrode is used due to its low resistance, excellent ohmic contact, good adhesion with the underlying layer, ability to form a uniform and homogeneous film, and other reasons. is used. Conventionally, an etching method has been widely used to form this N electrode pattern, and this method will be explained with reference to FIGS. 2(A) and 2(B).

First, the N film 2 is deposited on the base layer 21 by vapor deposition or sputtering.
2, a resist pattern 23 corresponding to a desired electrode pattern is formed using photolithography technology to obtain a member as shown in FIG. 2(A).

Next, as shown in FIG. 2(B), this member is immersed in an etching solution, and using this resist pattern 23 as an etching mask, the portions of the N film 22 that are not covered by the mask 23 are selectively etched. Etch and remove, mask 2
The part of the membrane 22 directly under the mask 3 was left, and then a mask 23 was formed using a release agent and the cyst was removed, thereby forming an electrode pattern 24.

(Problem to be Solved by the Invention) However, in order to etch the film 22, an etching solution in which, for example, acetic acid and water are added to a mixed solution of phosphoric acid and nitric acid is used as standard. H inside
H2 gas bubbles are generated concentrated on the surface of the + ion cancer film 22, and as a result, the etching solution cannot completely contact the N film surface, resulting in poor etching. This etching defect becomes particularly noticeable when forming a fine N electrode pattern, and as a result, there is a drawback that the N electrode pattern cannot be formed with high precision.

In order to remove these H2 bubbles, ultrasonic vibrations are applied,
Alternatively, air or other bubbles can be applied to the H2 bubbles from the outside to
A method of removing air bubbles from the surface of the layer film 2 has also been carried out, but even in that case, particularly small air bubbles could not be removed.

Further, when applying ultrasonic vibration, there was a risk of damaging the base layer 21.

An object of the present invention is to provide a method for forming a fine layer electrode pattern with high precision by performing etching while preventing the formation of H2 gas bubbles on the surface of a +61Q film.

(Means for solving the problem) In order to achieve this object, in the present invention, after A11lfJ is deposited on the underlayer, an etching mask is formed on the N film, and then an etching solution is applied. When etching this layer using etching to form an N electrode pattern of an electronic component, it is recommended to perform this etching with a material having a smaller ionization tendency than N bonded to a part of this layer. Features.

(Function) According to this method, a local electrode is created between N and the member in the etching solution, with the member serving as a cathode.
Since the H+ ions are concentrated on the surface of this component and not on the surface of the layer, no H2 gas bubbles are generated that would cause etching defects.Therefore, the layer can be etched with high precision, resulting in clean and sharp etching. It is possible to form an N electrode pattern.

(Explanation of Examples) Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIGS. 1(A) to 1(C) are process diagrams for explaining the present invention in detail. First, in the same manner as before, an AQ layer 2 is laminated on a base layer 1 by vapor deposition or sputtering, and then a desired N electrode to be formed is formed on this layer 2 using photolithography technology. A resist pattern 3 having the same pattern as the pattern is formed. Next, this layer film 2
In the upper part where resist pattern 3 is not formed,
A further layer 4 of a material with a lower ionization tendency than N, for example Ni, is bonded by some means. For example, it is preferable to form the island-like layer 4 by depositing the Ni material in the form of small islands on the surface of the N film. A portion of the member thus obtained is shown in a perspective view in FIG. 1(A).

Next, when this member is immersed in an etching solution and etching is performed using this resist pattern 3 as an etching mask, not only the layer 2 directly under the mask 3 but also the layer directly under the island-like layer 4 are etched. 2 is not etched, but the remaining portions of the membrane 2 are etched to obtain a member as shown in FIG. 1(B).

However, during this etching, the ionization tendency of N is
Since the ionization tendency is larger than that of Ni, a potential difference is generated between the layer film 2 and the island-like layer 4, and a local current flows between them with the island-like layer 4 serving as a cathode. Therefore, the H+ ions in the etching solution concentrate on the island-shaped layer 4, that is, the surface of the Ni member, and the H ions dissipate from the surface of the layer 2, so that no H2 gas is generated from the layer 2 side. Therefore, the etching solution comes into uniform contact with the surface of the AQ and film 2, which accelerates the etching speed and allows etching to be performed uniformly and with high precision even in the case of fine patterns.

Next, after applying, for example, a photoresist with a brush to the etched surface of the layer film to be left as the N electrode pattern, the island-shaped layer 4 and the portion 2a of the layer film 2 below it are etched and removed. When the resist pattern forming the post-etching mask 3 is peeled off, as shown in FIG. 1(C),
Only the N of the N film 2 that covered the mask 3 is obtained as the remaining thin electrode pattern 5. Since this N electrode pattern 5 is etched with high precision, it becomes a beautiful and sharp pattern.

The etching solution used in the above-mentioned embodiments is the same as the conventional etching solution having the components described above. However, since Ni is not etched with this etching solution, after the N etching is completed, Xi is etched with the etching solution for the old etching. Alternatively, even when using a simultaneous etching solution with and Xi, Ni is hardly etched during N etching, so Ni is etched after N etching is completed, and therefore, N etching and etching are performed. No H2 gas is generated from above the surface of the N film 2.

In the two examples, Ni was used as a material with a smaller ionization tendency than N, but materials other than Ni, such as Cu, Si, Fe, Ag, and AuvW, which are relatively easy to form a film, may be used. May be used.

Furthermore, in the above-mentioned embodiment, an example was explained in which the Xi material was vapor-deposited after the resist pattern was formed, but this material may also be formed before the resist pattern is formed, and in any case, the Xi material may be vapor-deposited before the etching. It would be good if it was done.

Furthermore, the method of bonding the material having a smaller ionization tendency than N to the N film is not limited to double vapor deposition.
The method does not matter.

In addition, a small amount of other substances, for example 0.3 to 1.0% by weight, may be added to N.
Even if Cu is included, it is included in the above-mentioned concept of the N electrode.

(Effects of the Invention) As is clear from the above explanation, according to the N electrode pattern forming method of the present invention, a local battery can be formed by bonding a material having an ionization tendency smaller than that of N to an N film. Since this is a method of etching
Since no H2 gas is generated on the surface of the membrane,
A beautiful and sharp M electrode pattern can be obtained with high precision.

[Brief explanation of drawings]

FIGS. 1A to 1C are process diagrams for explaining the N electrode pattern forming method of the present invention, and FIGS. 2A and 2B are process diagrams for explaining the conventional method. 1... Base layer, 2... M film 3... Resist pattern (or etching mask) 4
...(Made of material with smaller ionization tendency than AQ)
Island-like layer 5: part of the AQ film (underneath the island-like layer). Patent Applicant: Oki Electric Industry Co., Ltd. Representative Patent Attorney Takashi Ogaki Figure 1

Claims (1)

[Claims] After depositing the N film on the base layer, an etching mask is formed on the AQ film, and then the N film is etched using an etching solution to form the N electrode pattern of the electronic component. A method for forming an N electrode pattern, characterized in that the etching is performed in a state in which a material having a smaller ionization tendency than M is bonded to a part of the N film.