KR101564291B1 - Composition of a silver alloy target for a sputtering process - Google Patents

Abstract

The silver alloy target composition for the sputtering process contains palladium (Pd) in an amount of 0.4 to 2.0% by weight, indium (In) and silver (Ag) in an amount of 0.05 to 0.6% by weight and unavoidable impurities.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a silver alloy target composition for a sputtering process,

The present invention relates to a target composition for a sputtering process. More particularly, the present invention relates to a target composition for a sputtering process used in forming a conductive structure electrically connected to a transparent conductive film such as indium tin oxide (ITO) through a sputtering process.

Generally, an organic EL element includes an anode, a cathode, and an organic light-emitting layer interposed between the anode and the cathode. When a voltage is applied between the anode and the cathode, holes move from the anode and electrons move from the cathode to the organic organic light emitting layer, respectively. Light is generated when holes and electrons are combined in the organic light emitting layer.

The electrodes such as the anode or the cathode are made of a transparent conductive material. For example, the conductive material may be made of indium-tin-oxide (ITO). And an electrode pad for applying electricity to the anode or the cathode is formed. The electrode pad may be made of a metal having a good conductivity, for example, a silver alloy.

When wet etching is performed to form an electrode made of the ITO material and an electrode pad made of the silver alloy, an excellent etching selectivity ratio between the silver alloy and the ITO is required. Excellent adhesion between the electrodes and the electrode pad is required. In addition, agglomeration due to migration of silver ions included in the electrode pad occurs in a subsequent high-temperature process after the electrode pad is formed, so that the problem of coarse grains must be solved.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and provide a composition for a target for a sputtering process used in a sputtering process to form an electrically conductive structure having an improved adhesive force and a more dense grain.

According to an aspect of the present invention, there is provided a silver alloy target composition for a sputtering process, which comprises 0.4 to 2.0% by weight of palladium (Pd), 0.1 to 0.6% by weight of indium (In) silver (Ag) and unavoidable impurities. Here, the silver alloy target composition for a sputtering process may have an average grain size in the range of 20 to 50 mu m.

The conductive structure formed by the sputtering process using the silver alloy target for sputtering according to the preferred embodiment of the present invention may have dense crystal grains and thus have excellent heat resistance and corrosion resistance. Accordingly, it is possible to have an excellent etch selectivity in the etching process using the etching solution. Furthermore, the conductive structure formed through the sputtering process using the silver alloy target can have an excellent adhesive force between the underlying ITO film.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims It can be understood that

1 is a phase diagram of silver (Ag) and palladium (Pd).
FIG. 2 is a phase diagram of silver (Ag) and indium (In).
3 is a photograph of a silver alloy target according to an embodiment of the present invention and Comparative Examples 1 and 2.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention is capable of various modifications and various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. In the accompanying drawings, the sizes and the quantities of objects are shown enlarged or reduced in size in order to clarify the present invention.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprise", "comprising", and the like are intended to specify that there is a feature, step, function, element, or combination of features disclosed in the specification, Quot; or " an " or < / RTI > combinations thereof.

On the other hand, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

Silver alloy target composition for sputtering process

The silver alloy target composition for the sputtering process comprises 0.4 to 2.0 wt% palladium (Pd), 0.05 to 0.6 wt% of indium (In), and the balance silver (Ag) and unavoidable impurities.

1 is a phase diagram of silver (Ag) and palladium (Pd).

Referring to FIG. 1, the palladium (Pd) inhibits the migration of silver (Ag) ions contained in a silver alloy target when steam is supplied at a high temperature. For example, when the annealing process is performed at a high temperature such as 200 ° (= 473 K), one phase can be stably maintained regardless of the composition ratio between -Palladium. Accordingly, the palladium element inhibits the migration of the silver ions, so that the conductive structure formed through the sputtering process using the silver alloy target can maintain fine grains even under high temperature conditions. As a result, the conductive structure can have excellent heat resistance and excellent corrosion resistance to an etchant such as hydrochloric acid.

On the other hand, when the palladium has a mass ratio of less than 0.4% by weight, the above-described properties of palladium can not be exhibited. On the other hand, when the mass ratio of the palladium exceeds 2.0% by weight, the electrical resistance of the conductive structure deteriorates, And the corrosion resistance may be deteriorated. Accordingly, the palladium may have a mass ratio of 0.4 to 2.0 wt% based on the total mass of the silver alloy target.

FIG. 2 is a phase diagram of silver (Ag) and indium (In).

Referring to FIG. 2, the indium (In) may function as a crystal nucleus of the silver alloy target. That is, in the subsequent annealing process, a grain may be formed with the indium element as a crystal nucleus. Therefore, the silver alloy target can have a dense grain, and the surface roughness can be lowered. As a result, the indium can improve the heat resistance while suppressing the coarsening of the silver alloy target.

Meanwhile, as shown in FIG. 2, the silver (Ag) and the indium (In) have an intermetallic phase (IMP) according to their composition ratios and temperatures. Therefore, the silver alloy target may have a dense grain structure.

On the other hand, when the indium has a mass ratio of less than 0.05% by weight, the above indium properties can not be exhibited. On the other hand, when the indium is in a mass ratio exceeding 0.6% by weight, the electrical resistance of the conductive structure deteriorates, Can be exacerbated. Accordingly, the indium may have a mass ratio of 0.05 to 0.6% by weight based on the total weight of the silver alloy target.

Further, when a conductive structure is formed on the ITO film by the sputtering process using the silver alloy target, the adhesion between the ITO film and the conductive structure can be improved by containing the indium element in both the ITO film and the conductive structure.

The silver (Ag) can impart a very low specific resistance, that is, excellent electric conductivity, to the conductive structure formed by the sputtering process using the silver alloy target.

On the other hand, the unavoidable impurities may be mixed with the silver alloy target in a weight ratio of less than 0.001% by weight of bismuth (Bi), iron (Fe), manganese (Mn), nickel (Ni)

Method for producing silver alloy target composition for sputtering process

First, silver (Ag) having a purity of 99.99% or more, palladium (Pd) having a purity of 99.99% or more, and indium (In) having a purity of 99.99% or more are prepared.

The silver (Ag) is dissolved and palladium and indium are further incorporated into the dissolved silver (Ag). Then, palladium and indium are dissolved in silver (Ag). The dissolution step may be performed in an inert gas atmosphere. The dissolution process may be performed in an induction furnace. The palladium is controlled to a mass ratio of 0.4 to 2.0 wt%, and the indium is controlled to a mass ratio of 0.05 to 0.6 wt%. Whereby a silver alloy ingot including palladium, indium and silver is formed.

Then, the silver alloy ingot is heated and a hot rolling step is performed. The hot rolling process may be performed at a temperature of 400 to 700 ° C. The pass schedule of the hot rolling process can be appropriately adjusted.

Thereafter, the quenching process is performed. The quenching process may be carried out at a cooling rate of 200 to 1,000 ° C / min. The quenching process may be performed using a water shower.

A silver alloy target is produced as a subsequent process such as a calibration process and a plying process is performed on the rolled plate obtained through the above processes.

The silver alloy target may have improved corrosion resistance, heat resistance, and reduced specific resistance as it has a dense grain structure.

Example

(Ag) having a purity of 99.99 mass% or more, palladium (Pd) and indium (In) having a purity of 99.9 mass% or more as an additive material were prepared and loaded in a high frequency induction melting furnace in a graphite crucible. In the dissolution step, silver (Ag) was first dissolved. After that, palladium and indium were added to form an alloy melt. At this time, the palladium and the indium were adjusted to have a weight ratio of 1.90 wt% and 0.54 wt%, respectively.

The alloy melt was sufficiently stirred by induction heating, and subsequently a silver alloy ingot was produced as a cast iron mold.

Thereafter, the silver alloy ingot was heated to 700 DEG C, and rolled in the X direction and the Y direction was repeatedly stretched.

After the hot rolling process, the rolled plate was heated at 300 ° C / min. Lt; / RTI >

After the quenching step, the rolled plate was processed using a roller leveler to produce a silver alloy target for sputtering.

Comparative Example 1

Silver (Ag) having a purity of 99.99% by mass or more and palladium (Pd) having a purity of 99.9% by mass or more as an additive material were prepared and the palladium was adjusted to have a weight ratio of 1.91% by weight. A silver alloy target for stuffering was produced under the same conditions as in Example except that indium (In) was not added at this time.

Comparative Example 2

Palladium (Pd) and copper (Cu) having a purity of 99.9% by mass or more were prepared as an additive material and the palladium was 1.90% by weight and the copper (Cu) was 0.51% by weight . A silver alloy target for stuffering was produced under the same conditions as those of the example except that copper (Cu) was added instead of indium (In).

Evaluation of silver alloy target for sputtering process

The grain sizes for the above-described Examples and Comparative Examples 1 and 2 are measured. The values are shown in Table 1 below.

NO division Ag (w%) Pd (w%) Cu (w%) In (w%) Average Grain size (탆) Resistivity
(μΩcm) Comparative Example 1
Mixing ratio 98.09 1.91 - - Target weight ratio 98.10 1.90 - - 120 - Comparative Example 2
Mixing ratio 97.59 1.90 0.51 - Target weight ratio 97.68 1.87 0.45 - 150 7.1 Example
Mixing ratio 97.55 1.91 - 0.54 Target weight ratio 97.57 1.90 - 0.53 26 2.7

3 is a photograph of a silver alloy target according to an embodiment of the present invention and Comparative Examples 1 and 2.

As shown in FIG. 3 and Table 1, it can be confirmed that the average grain size (26 μm) is smaller than that of Comparative Examples 1 and 2 according to the embodiment. Therefore, the silver alloy target according to the embodiment has a dense structure. At this time, according to a generally known diameter measurement method, the average grain size corresponds to the average diameter of the grain assuming that the grain is completely spherical.

On the other hand, the resistivity value was subjected to a sputtering process using the silver alloy targets for sputtering to form a conductive structure on the substrate. The sputtering process was performed under the condition that the distance between the target and the substrate was set to 50 mm and the argon gas pressure was adjusted to 0.5 P by a DC 1000 W power source. Thereafter, an annealing process was performed on the conductive structure at a temperature of 500 °.

As shown in Table 1, it can be seen that the conductive structure according to the embodiment has a very low resistivity (2.7 mu OMEGA cm) value. Therefore, it can be confirmed that the conductive structure formed in the sputtering process using the silver alloy target for stirling has excellent electric conductivity.

The silver alloy target for sputtering according to the present invention can be applied when a conductive structure such as an electrode pad included in an organic light emitting display is formed by a sputtering process.

Claims (2)

0.4 to 2.0% by weight of palladium (Pd);
0.05 to 0.6% by weight of indium (In); And
The remainder contains silver (Ag) and unavoidable impurities,
≪ / RTI > has an average grain size in the range of 20 to 50 < RTI ID = 0.0 > um. ≪ / RTI > delete

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