JPS605239B2 - Method for forming thin film conductor patterns - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a thin film conductor pattern which is advantageous in terms of resource saving.

Conventionally, in the process of forming thin film conductor patterns such as thin film wiring, a metal film is deposited on an insulating substrate by vapor deposition, sputtering, etc., a photoresist is applied thereon, and selectively formed by baking, exposing, and developing. In the process of forming a thin film conductor pattern by etching away the metal in the areas where the resist is gone, dust or dirt on the glass drying plate may leave unnecessary parts in the pattern, or conversely, the metal in the necessary parts may be removed. There are things that are going away right now.

Such thin film conductor patterns are often used in micro parts such as ICs and BIs, hybrid circuit boards, and more recently, heat-generating recording thermal head boards. However, if these patterns have the above-mentioned defects, These parts or boards become defective products. Among these defects, unnecessary portions remaining in the pattern can be easily removed by applying photoresist again and etching again.

However, it has been considered impossible to correct defects such as missing parts of the pattern, such as broken wires. That is,
If such a defect occurs, the entire pattern must be peeled off and discarded, and the entire process must be restarted, or, in the worst case scenario, the part on which this pattern is formed must be disposed of as a defective product that cannot be corrected. It was extremely wasteful in terms of resource conservation. The present invention has been made in view of the above-mentioned problems, and its purpose is to provide a method of forming a thin film conductor pattern that can correct missing parts of necessary parts and effectively save resources.

In the present invention, on a conductor pattern formed by selectively etching a first metal film including an adhesive layer deposited on an insulating substrate, a conductive pattern made of a metal different from the first metal film including an adhesive layer is formed. After depositing a second metal film made of the same material over the entire surface of the substrate, the second metal film is etched with an etchant that does not attack the first metal film to eliminate any missing conductor pattern made of the first metal film. It is characterized in that it is patterned into almost the same pattern as the conductor pattern so as to complement it.

In this case, the materials for the first metal film and the second metal film and the etchant for etching the second metal film that does not attack the first metal film are, for example, shown in the following table {1} to 'IQ. selected by a combination of

Table (1) Table (2) Table (3) Table (4) Table (5 Table 7) Table (8) Table (9) Table (10) As an etchant for Tj, the present inventor Water 5, as already proposed by Tokusho 53-82685.
benzotriazole 0.1 to 5 days per 0';
30 to 120% hydrogen peroxide, aqueous ammonia (NH
40H) and ammonium salts (however, for ammonia water, 0.5 to 10M;
For ammonium salts, it is also possible to use a solution containing 2 to 30 ml of ammonium salt.

Hereinafter, this invention will be explained in detail with reference to Examples.

The figure shows a process diagram of an embodiment of the present invention. First, as shown in FIG. 1, a Cr film 2,... Pd
The films 22 and A column 23 are uniformly deposited in this order by vapor deposition or sputtering.

Then, this metal film 2 is selectively etched to form a conductor pattern as shown in FIG. 2, for example. In FIG. 2, reference numeral 3 indicates a missing part of the conductor pattern. If this conductive pattern is a wiring, this missing part will result in a disconnection and the pattern will be defective. In this embodiment, the first
As shown in FIG. 3, a Ti film 4, a Cu film 42 are deposited over the entire surface of the substrate 1 as a second metal film 4 by vapor deposition or sputtering in this order on the conductive pattern formed by the metal film 2. Covers the whole area.

Next, a photoresist is applied onto this second metal film 4, aligned with the conductor pattern formed by the first metal film 2, and the photoresist is exposed and developed using a glass mask that does not break. do. Then, the Cu film 42 is etched, for example, with a 20% aqueous solution of ammonium persulfate, and then the Ti film 4 is etched with a 2% solution of fluoric acid.
As shown in FIG. 4, the second metal film 4 is patterned into almost the same pattern as the conductor pattern formed with the first metal film 2. Then, as shown in FIG.

As a result, the defects 3 in the conductor pattern formed of the first metal film 2 are corrected by being complemented by the conductor pattern formed of the second metal film 4.
Note that when etching the second metal film 4, the above-mentioned etchants do not attack the Cr film 2, Pd film 22, and Au film 23 at all, so the conductor pattern formed by the first metal film 2 will never become over-sexy. Furthermore, the same effect can be obtained by depositing AI instead of Cu/Ti as the second metal film and etching it with an aqueous solution of sodium hydroxide.

Furthermore, even if the deposition of the second metal film for correction is redone due to defective vapor deposition or the like, the conductor pattern formed by the first metal film that has already been formed will not be damaged.

The method of this embodiment is particularly effective when the thin film conductor pattern is defective even in one place, and the cost of the defective product is high.

A specific example of such a device is, for example, a thermal head for heat-sensitive recording. In the manufacturing process of this thermal head, a multilayer thin film of, for example, Cr/Au/Pd/Cr is deposited on a thin film resistor layer uniformly formed on a ceramic substrate, and this thin film is etched to form electrode wiring. After forming,
The thin film resistor layer is etched to form a heat generating resistor array that will become a recording element. At this time, if the electrode wiring made of Cr/Au/Pd/Cr is disconnected, conventionally not only the electrode wiring but also the resistor had to be discarded.

According to this invention, in such a case, the disconnection can be corrected, so materials such as Au used for electrode wiring materials and Ta used as resistor material can be used without being thrown away, thereby saving resources. It is extremely effective. In addition,
When using Ti in a part of the second metal film, using hydrofluoric acid as an etchant for Ti will attack Td, but the etchant shown in the above-mentioned Tokiso Sho No. 53-82685 If you use , there will be no such inconvenience.

In addition, since it is necessary to deposit Ta205 or the like on the head surface as an abrasion-resistant film in the thermal head, the second metal film for correction is made of Ti, which has a large free energy of oxidation formation.
A Ti/Cu/Ti multilayer thin film containing Ti/Cu/Ti is suitable.

[Brief explanation of the drawing]

FIGS. 1 to 4 are process diagrams of an embodiment of the present invention, and in each figure, a is a plan view and b is a sectional view. 1... Insulating substrate, 2... First metal film,
3... Missing, 4... Second metal film. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. On a conductive pattern formed by selectively etching a first metal film including an adhesive layer deposited on an insulating substrate, a conductive pattern including an adhesive layer and made of a metal material different from the first metal film is formed. After depositing the second metal film over the entire surface of the substrate, the second metal film is etched using an etchant that does not attack the first metal film to compensate for missing conductor patterns made of the first metal film. 1. A method for forming a thin film conductor pattern, which comprises patterning the thin film conductor pattern into a pattern substantially identical to the conductor pattern.