KR101319569B1 - Manufacturing method of High density Target, utilizing waste Targets consisting of Zinc Oxide, Gallium Oxide and Indium Oxide - Google Patents

Abstract

The present invention provides a method for manufacturing a high-density sputtering target with a simple and high yield by recycling only a waste target made of indium oxide, gallium oxide, and zinc oxide, by applying only a dry process without a wet dissolution process.

Description

Manufacturing method of High density Target, utilizing waste Targets consisting of Zinc Oxide, Gallium Oxide and Indium Oxide

The present invention relates to a method for producing a sputtering target material made of indium, gallium, and zinc oxide used in a transparent conductive film for display.

Recently, with the development and interest in various flat panel displays such as LCD, PDP and OLED, research into transparent conductive film materials having excellent light transmittance and electrical conductivity has been actively conducted. The target composition consisting of indium, gallium, and zinc oxide has the highest mobility and reaction speed in the transparent electrode material, which is the most interesting and researched to be applied for large area display.

However, indium and gallium are rare resources, and because the price is high due to the limit of the reserves, the target price is very high and the burning rate is about 30 ~ 40% when using the planar type target, so the research of the manufacturer and the industry for the recycling is continuously required.

The present invention relates to a method for producing a high-density target for a transparent electrode by recycling the target scrap, there is no change in composition and the original target.

And also to a method for producing a target at a lower sintering temperature than originally through the sintering aids in the production of the target.

Expensive indium and gallium extraction and metallization from the target material consisting of indium oxide, gallium oxide and zinc oxide have already been developed, and there are many manufacturers' movements to improve the yield.

However, the present invention provides a high-density sputtering target manufacturing method by applying only a dry process to the waste target without a wet dissolution process.

The target consisting of the composition is generally sintered at a temperature of 1450 ℃ or more in order to achieve a known high density.

In order to recycle such a high-density waste target, it is atomized through a pulverization process, and the finely divided powder is reassembled to form a formed body. A process for sintering the formed body to make a high-density target is required.

In the process of making a high-density sintered body, a sintering aid is used to produce a high-density target at a temperature lower than the temperature of the existing target, and the additive is added so as not to break the existing composition.

Sintering by lowering the sintering temperature may cause volatilization of a specific component at a high temperature upon re-sintering of the sintered powder, which may cause compositional deviation. In addition, there is an advantage in cost reduction in terms of the process in low-temperature sintering.

The present invention provides a method for producing a high-density sputtering target in a simple and high yield by applying only a dry process to a waste target consisting of indium oxide, gallium oxide and zinc oxide without a wet dissolution process.

In order to recycle a waste target made of indium oxide, gallium oxide and zinc oxide, a high density target is required.

(a) first step: heating the target to a temperature of 900 ℃ or more,

(b) second step: quenching the heated target to soften the tissue,

(c) third step: coarsely pulverizing the quenched target,

(d) fourth step: pulverizing the coarsely pulverized target,

(e) fifth step: sieving the pulverized powder,

(f) Step 6: beads milling the sieved powder,

(g) Step 7: adding a sintering aid to the beads mill and mixing them,

(h) Step 8: making the mixed slurry into granulated powder,

(i) the ninth step: making the assembled powder into a molded body, and

(j) Step 10: Sintering the molded body to manufacture a high-density target.

Next, the present invention will be described in more detail as examples and test examples.

Step 1: heating the waste target at a temperature of 900 to 1100 占 폚 for 2 hours;

Step 2: The heated target is heated to a constant temperature

           Followed by quenching in the vessel;

Step 3: The quenched target may be cracked

          Some targets have cracks, which can be used to

          Put in to conduct coarse grinding;

Step 4: The pulverized powder was pulverized using a ball mill,

           Gt; 20 < / RTI > pie zirconia balls for at least 24 hours;

Step 5: The fine pulverized powder was sieved to a size of 125 microns using a sieve of 120 to 150 mesh

           Ron or less, and at this time, the powder does not pass through the sieve scale

           The silver powder was ball milled again;

Step 6: The sieved powder is fixed in pure water to which dispersant is added in 0.5∼1.0w%

           Dispense in one volume. At this time, the sieved fine powder does not sink

           Perform the rock agitation sufficiently and do not apply the powder at once

           All. If the stirring speed is not fast when put into the mixer,

           Since the aggregation occurs, it is necessary to confirm the degree of dispersion,

           Enter;

Step 7: Primary dispersion through beads mill and sintering in finely divided slurry

           Add assistant B203. The amount of B203 added is the target

           Add 0.1w% ~ 0.05w%, which is the level of basic composition.

           When added in an amount less than 0.05w%, it has little effect as a sintering aid.

           The density is realized. Moldability in the production of molded products after sintering additive

           To achieve this, add binder in an amount of 0.5w% ~ 1w%

           followed by beads mill treatment;

Step 8: The thus mixed slurry is sprayed using a spray drier

           And dried. The spray-dried powder was granulated using a 150 mesh sieve

           Remove horses;

Step 9: The granulated powder is subjected to primary molding,

           And then a pressure-reduced molding is carried out to produce a molded body having a sufficient molding strength;

10th step: The molded product was sintered at a temperature of 1200 ° C. or higher and 02 gas.

To produce a high density target.

[Test Example 1]

When the waste target of Example 1 was heated to a high temperature, the heating temperature was changed to confirm the change in content of the metal constituting the target and the coarse grinding yield. The results are shown in Table 1. When heated to a temperature of more than 1100 ℃ change in composition occurs.

This was confirmed through ICP analysis, and In, Ga, Zn contents were compared.

It is observed that the composition change of more than 1% due to the volatilization of Zn, such a large composition change was not observed at a temperature of 1050 ℃ or less.

When the waste target of Example 1 was heated to 1000 ° C except 1100 ° C when heated to a specific temperature, it showed the highest coarse grinding ratio based on the particle size of 5 mm or less.

[Test Example 2]

The density according to the amount of B203 addition was tested and the results are shown in Table 2.

The density of the existing target is over 99%. It should have a density equal to or higher than the present target to have stable characteristics in the thin film process. Sintering aid was added at 0.04w% to 0.12w% and the sintering temperature was evaluated at 1150 ~ 1450 ℃.

The amount of B203 added was the highest density from 0.1w% to 99.1% and the sintering temperature was observed at 1250 ℃.

Although 0.12w% of the added amount represents 99%, the density is 0.1% lower and the amount of B203 added into the impurity is more suitable than that of 0.1w%.

The added amount of less than 0.08w% did not realize a high density of more than 99%, and the sintering temperature was continuously increased due to the increase in density.

[Test Example 3]

The specific resistance of the target itself was measured under the highest density of target according to the amount of B203 added, and the results are shown in Table 3.

To have stability in the sputter process, it must have a resistivity of 9.0 x 10 ^-3 Ωcm or less. As a result of measuring the specific resistance, all targets except the sintered body added with B203 0.04w% showed electrical conductivity satisfying the specific resistance condition.

Claims (4)

Waste target consisting of indium oxide, gallium oxide and zinc oxide
(a) heating to a temperature of 900 DEG C or higher;
(b) quenching the heated target to soften the tissue;
(c) coarsely pulverizing the quenched target;
(d) pulverizing the coarsely pulverized target;
(e) sieving the pulverized powder;
(f) beads milling the sieved powder;
(g) adding a sintering aid to beads mill and mixing them;
(h) making the mixed slurry into granulated powder;
(i) making the assembled powder into a formed body; And
(j) A method for producing a high density target consisting of indium oxide, gallium oxide and zinc oxide from a waste target characterized by sintering a molded body. The method of claim 1 wherein step (a) is performed at a temperature of 1100 ° C. or less. The method according to claim 1, wherein 0.05 g% to 0.1 w% of B203 is added to the sintering agent in the step (g). The method according to claim 1, wherein the binder is further added in an amount of 0.5w% to 1.0w% in the step (g).