KR101446615B1 - Method for manufacturing (indium, gallium, zinc, oxide target and indium, gallium, zinc, oxide target by using the same - Google Patents

Abstract

More particularly, the present invention relates to a method for manufacturing a target, and more particularly, to a method for manufacturing a target, which comprises mixing indium oxide (In ₂ O ₃ ) powder, gallium oxide (Ga ₂ O ₃ ) powder and zinc oxide (ZnO) A target manufacturing method and an IGZO target produced thereby.
To this end, the present invention relates to a dispersion process in which indium oxide (In ₂ O ₃ ) powder, gallium oxide (Ga ₂ O ₃ ) powder and zinc oxide (ZnO) powder are mixed with a dispersant and dispersed, Indium powder, gallium oxide powder, and zinc oxide powder to form a compact, and then sintering the compact.

Description

[0001] The present invention relates to an IGZO target manufacturing method and an IGZO target manufactured by the method,

More particularly, the present invention relates to a method for manufacturing a target, and more particularly, to a method for manufacturing a target, which comprises mixing indium oxide (In ₂ O ₃ ) powder, gallium oxide (Ga ₂ O ₃ ) powder and zinc oxide (ZnO) A target manufacturing method and an IGZO target produced thereby.

Recently, the use of zinc oxide thin films has been increasing.

Conventionally, a polycrystalline silicon film or an amorphous silicon film is mainly used as a channel layer of a thin film transistor.

However, in the case of the polycrystalline silicon film, the electron mobility is limited due to the scattering of electrons occurring at the polycrystalline particle interface. In the case of the amorphous silicon film, the electron mobility is very low and the device is deteriorated with time, have.

In recent years, studies have been actively conducted to form a thin film of zinc oxide, which is amorphous or microcrystalline and has excellent electron mobility, as a TFT channel layer.

Unlike the transparent conductive film, the amorphous or microcrystalline oxide thin film has amorphous or nanocrystalline characteristics and exhibits a semiconductor characteristic, and thus can be used as a channel between the source and the drain of the TFT.

In addition, since the amorphous silicon thin film is transparent, a transparent TFT can be constituted, and the flatness can be improved which can not be achieved in the conventional polycrystalline silicon thin film.

As a method of forming the oxide thin film for a transparent semiconductor, there are sputtering, pulse laser deposition (PLD), electron beam deposition (Electron Bean Deposition) and the like using a polycrystalline sintered body as a target.

Since double sputtering is easy to apply in mass production, research is being conducted on a method of manufacturing a target capable of depositing a thin film by sputtering.

Specifically, in the sputtering method, a substrate is used as an anode under a gas pressure of about 10 pa or less, a sputter target of a transparent oxide thin film to be formed is used as a cathode, and a glow discharge is caused therebetween, So that the argon cations in the plasma collide with the sputtering target of the cathode, whereby particles having a mutually pulling force are accumulated on the substrate to form a thin film.

The sputtering method includes an RF sputtering method using a high frequency (RF) plasma and a DC sputtering method using a DC (direct current) plasma according to a method of generating an argon plasma.

The dual DC sputtering method is mainly used for industrial use because of its high deposition rate and simple operation.

Among the oxide semiconductor targets, the material for which mass production technology is developed at the fastest rate is the IGZO target.

The IGZO target is capable of DC sputtering and is advantageous for maintaining the uniformity of the TFT device by maintaining the amorphous state at room temperature deposition.

Among the IGZO targets, the most commercially available composition is a composition of In ₂ O ₃ : Ga ₂ O ₃ : ZnO = 1: 1: 1 in terms of at%.

The commercialized target crystal phase of this composition is divided into an In-Zn-O composition phase and a ZnGa ₂ O ₄ spinel phase.

The In-Zn-O composition phase and the spinel phase have different structures and compositions, and thus have different electric conductivity, thermal conductivity and hardness.

The difference between these two phases has a problem of causing nodules in the sputtering process.

In addition, the nodules generated during the sputtering process cause particle defects, which shortens the use time of the target.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems of the prior art as described above, and it is an object of the present invention to provide a method of manufacturing an In ₂ O ₃ powder, a gallium oxide (Ga ₂ O ₃ ) (ZnO) powders are mixed with a dispersant to disperse the ZnO powders, respectively, so as to produce a single-phase target in which phases are not separated, and an IGZO target produced by the method.

To this end, the IGZO target manufacturing method according to the present invention is a method of manufacturing an IGZO target by dispersing an indium oxide (In ₂ O ₃ ) powder, a gallium oxide (Ga ₂ O ₃ ) powder and a zinc oxide (ZnO) And a sintering process in which the dispersed indium oxide powder, gallium oxide powder, and zinc oxide powder are mixed and formed into a compact and then sintered.

Preferably, the dispersing step includes a first dispersing step of mixing the indium oxide powder and the first dispersing agent and then dispersing the dispersion to prepare an indium oxide dispersion, mixing the gallium oxide powder and the second dispersing agent, And a third dispersing step of mixing and dispersing the zinc oxide powder and the third dispersing agent to prepare a zinc oxide dispersion.

Preferably, the dispersion is dispersed by wet milling.

Preferably, the first dispersant is added so that the polyacrylic acid amine salt of the indium oxide powder 100 having a weight average molecular weight of 5000 is added in 1.0 weight ratio.

Preferably, the second dispersant is added so that the polyacrylic acid amine salt having a molecular weight of 3000 relative to the gallium oxide powder 100 weight ratio is added to 0.5 weight.

Preferably, the third dispersant is added to 1.0 gallon of the polyacrylic acid amine salt having a molecular weight of 2000 relative to the gallium oxide powder 100 weight ratio.

Preferably, the sintering process includes a slurry producing step of mixing a dispersed indium oxide powder, a gallium oxide powder and a zinc oxide powder to form a slurry, a binder adding step of adding a binder to the slurry, A granulating step of spray drying the slurry to form granular powder, a molding step of making the granular powder into a molded body, and a sintering step of sintering the molded body to obtain a sintered body.

Preferably, the binder uses polyvinyl acetate (PVA).

Preferably, the molding step is primary molded by a cold press method, and secondary molded by a cold isostatic pressing method.

Preferably, the sintered body is sintered at a temperature range of 1200 to 1300 ° C and 1400 to 1500 ° C in an air atmosphere and an oxygen-free atmosphere to produce a sintered body.

On the other hand, the IGZO target prepared by the above-mentioned method has a composition of InGaZnO ₄ It is done on a daily basis.

Here, the IGZO target may be a DC sputterable target.

At this time, the IGZO target may have a resistivity of 10 < ^-1 >

According to the present invention, formation of InGaZnO ₄ single phase forms fewer nodule generation than the target in which an In-Zn-O composition phase and ZnGa ₂ O ₄ phase separation occur, thereby maximizing the target use time.

1 is a flow diagram illustrating an IGZO (Indium, Gallium, Zinc, Oxide) target manufacturing method 100 according to an embodiment of the present invention.
FIG. 2 is a process flow chart showing in detail a dispersion process (S110) of an IGZO (Indium, Gallium, Zinc, Oxide) target manufacturing method 100 according to an embodiment of the present invention.
FIG. 3 is a process flow chart showing in detail a sintering process (S120) of an IGZO (Indium, Gallium, Zinc, Oxide) target manufacturing method 100 according to an embodiment of the present invention.
4 is an EPMA image of an IGZO (Indium, Gallium, Zinc, Oxide) sintered body manufactured according to an embodiment of the present invention.
5 is a graph showing XRD measurement results of IGZO (Indium, Gallium, Zinc, Oxide) sintered bodies manufactured according to an embodiment of the present invention.

Hereinafter, a method of manufacturing an IGZO target according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In the present invention, IGZO means a compound of Indium, Gallium, Zinc, and Oxide.

The basic principle of the present invention is that the indium oxide (In ₂ O ₃ ) powder, the gallium oxide (Ga ₂ O ₃ ) powder and the zinc oxide (ZnO) powder are mixed with an optimized amount of dispersant Dispersed and mixed again.

In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

1 to 3, the same reference numerals are used for the same members.

FIG. 1 is a flow chart showing an IGZO (Indium, Gallium, Zinc, Oxide) target manufacturing method 100 according to an embodiment of the present invention.

Referring to FIG. 1, an IGZO target manufacturing method according to the present invention comprises mixing indium oxide (In ₂ O ₃ ) powder, gallium oxide (Ga ₂ O ₃ ) powder, and zinc oxide (ZnO) A dispersion process (S110), and a sintering process (S120) in which the dispersed indium oxide powder, gallium oxide powder, and zinc oxide powder are mixed to form a compact and then sintered.

A method of manufacturing an IGZO target according to an embodiment of the present invention constructed as shown in FIG. 1 will be briefly described below.

In the dispersion step S110, the indium oxide powder, the gallium oxide powder, and the zinc oxide powder are each dispersed.

In this case, the optimum dispersant is added to the indium oxide powder, the gallium oxide powder and the zinc oxide powder at different ratios.

Also, the dispersion is preferably dispersed using wet milling.

Thereafter, in the sintering process (S120), dispersed powders are mixed to prepare a slurry, and a binder for binding is added to the slurry.

Thus, the binder-added slurry is spray dried and granulated, and the granulated powder is molded.

Finally, the molded powders are sintered at specific temperatures to produce an IGZO target.

FIG. 2 is a process flow chart showing in detail a dispersion process (S110) of an IGZO (Indium, Gallium, Zinc, Oxide) target manufacturing method 100 according to an embodiment of the present invention.

Referring to FIG. 2, the dispersion process (S110) of the IGZO target manufacturing method according to the present invention will be described in detail.

The first dispersion step S110 includes a first dispersion step S111 in which an indium oxide dispersion A 'is prepared by mixing and dispersing indium oxide powder A and a first dispersant a, a gallium oxide powder B, A second dispersion step (S112) of mixing the zinc oxide powder (C) and the second dispersant (b) and then dispersing the mixture to prepare a gallium oxide dispersion (B '); And a third dispersion step (S113) of preparing a zinc oxide dispersion (C ').

Preferably, the steps of mixing and dispersing the respective powders A, B and C with the respective dispersants a, b and c are described as the first to third dispersion stages S111 to S113, (S111 to S113) may be performed in an arbitrary order.

Also, the dispersion is preferably dispersed by a wet milling method.

Therefore, distilled water may be added to each of the dispersion stages (S111 to S113) at the time of wet milling.

On the other hand, the respective dispersants (a, b, c) are added in different ratios for optimal dispersion of the respective powders (A, B, C).

For example, the first dispersant (a) is added so that 1.0 mass of the polyacrylic acid amine salt having the molecular weight of 5000 is dispersed in the indium oxide powder (A) 100.

And the second dispersant (b) is added so that the polyacrylic acid amine salt having a molecular weight of 3000 relative to the weight of the gallium oxide powder (B) 100 is added to 0.5 wt%.

Finally, the third dispersant (c) is added so that the polyacrylic acid amine salt having a molecular weight of 2000 relative to the weight of the gallium oxide powder (C) 100 is added to 1.0 weight.

FIG. 3 is a process flow chart showing in detail a sintering process (S120) of an IGZO (Indium, Gallium, Zinc, Oxide) target manufacturing method according to an embodiment of the present invention.

Referring to FIG. 3, the sintering process (S120) of the IGZO target manufacturing method according to the present invention will be described in detail.

(A '), a gallium oxide dispersion (B'), and a zinc oxide dispersion (C '), which are obtained by dispersing the respective powders (A, B, C) by wet milling in a dispersion process (S110) To produce slurry D (S121).

A binder E such as polyvinyl acetate (PVA) is added to the resulting slurry D as a binder (S122).

 The binder (E) to be added in the present invention is added for the purpose of improving the strength and sintering density of the shaped body during the production of the shaped body for producing the sputtering target.

That is, all the binders capable of maintaining the molding strength can be applied to the binder (E).

Thereafter, the slurry D to which the binder (E) is added is dried and transformed into a granular powder (F) (S123).

The slurry (D) is preferably granulated through spray drying.

The slurry D is dried in this way and the deformed granular powder F is formed into a compact (S124).

At this time, the spray-dried granular powder (F) is subjected to primary molding by a cold press method, followed by secondary molding through a cold isostatic pressing method and transformed into a molded article.

Thereafter, the formed body is sintered to produce a sintered body (S125).

The sintering step (S125) is a most important process in order to make the three constituents of the target exist in a uniform state, and is also an important process for maintaining the resistivity of the sintered body at 10 ^-1 Ωcm or less so that DC sputtering can be performed.

During sintering, materials such as Zn and Ga are volatilized at high temperatures, so control of sintering conditions is very important.

Therefore, in order to solve such a problem, in the present invention, a sintered body for zinc oxide-based sputtering can be manufactured by sintering at a temperature range of 1200 to 1300 ° C and 1400 to 1500 ° C in a combination of an air atmosphere and an oxygen-free atmosphere.

Through this special sintering condition, InGaZnO ₄ single phase can be formed without phase separation of In-Zn-O composition and ZnGa ₂ O ₄ .

In addition, since the InGaZnO ₄ single phase is formed, the generation of nodules is less than that of the In-Zn-O composition phase and the ZnGa ₂ O ₄ phase separation, thereby maximizing the target use time.

4 and 5 are graphs showing the results of measurement of the characteristics of a sintered body manufactured by the method of manufacturing an IGZO target according to the present invention. FIG. 4 is a graph showing the results of measurement of the characteristics of an sintered body of IGZO (Indium, Gallium, Zinc, FIG. 5 is a graph showing XRD measurement results of an IGZO (Indium, Gallium, Zinc, Oxide) sintered body manufactured according to an embodiment of the present invention.

Referring to FIG. 4, an electron probe micro analyzer (EPMA) image of the IGZO sintered body shows that In, Ga, and Zn are uniformly dispersed in the sintered body, and ZnGa ₂ O ₄ spinel phase It is proved that it is not formed.

5, it was confirmed that the diffraction pattern including the diffraction angle and the diffraction intensity of the IGZO sintered body manufactured according to the embodiment of the present invention had the same tendency as the diffraction pattern of InGaZnO _{4, and} the diffraction pattern including the intrinsic diffraction angle of InGaZnO ₄ , The IGZO sintered body manufactured according to the embodiment of the present invention was confirmed to be an InGaZnO ₄ single phase. Here, the diffraction pattern of InGaZnO ₄ can be confirmed from the JCPDS card.

In other words, through the EPMA image of FIG. 4 and the XRD measurement graph of FIG. 5, the IGZO target manufactured according to the embodiment of the present invention can be made of InGaZnO ₄ It was confirmed that it was done on a single day.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. This is possible.

Therefore, the scope of the present invention should not be limited by the described embodiments, but should be determined by the scope of the appended claims as well as the appended claims.

S110: dispersion process S120: sintering process
A: indium oxide powder a: first dispersant
B: Gallium oxide powder b: Second dispersant
C: zinc oxide powder c: third dispersant
A ': dispersion of indium oxide B': dispersion of gallium oxide
C ': zinc oxide dispersion D: slurry
E: binder F: granular powder
G: Molded body H: Sintered body

Claims (13)

A dispersion process in which an indium oxide (In ₂ O ₃ ) powder, a gallium oxide (Ga ₂ O ₃ ) powder, and a zinc oxide (ZnO) powder are mixed with a dispersant and dispersed; And
And a sintering step of mixing the dispersed indium oxide powder, gallium oxide powder and zinc oxide powder into a compact, and sintering the mixture,
The sintering process
A slurry producing step of mixing the dispersed indium oxide powder, gallium oxide powder and zinc oxide powder to form a slurry;
A binder adding step of adding a binder to the slurry;
A granulation step of spray drying the slurry to which a binder is added to form a granular powder;
A molding step of making the granular powder into a molded body; And
And sintering the formed body to obtain a sintered body,
The sintering step
Wherein the sintered body is manufactured by sintering the formed body at a temperature range of 1200 to 1300 ° C and 1400 to 1500 ° C in a combination of an air atmosphere and an oxygen-free atmosphere. The method of claim 1,
A first dispersion step in which the indium oxide powder and the first dispersant are mixed and dispersed to prepare an indium oxide dispersion,
A second dispersion step of mixing and dispersing the gallium oxide powder and the second dispersant to prepare a gallium oxide dispersion; and
And a third dispersing step of mixing the zinc oxide powder and the third dispersing agent and dispersing the zinc oxide powder to prepare a zinc oxide dispersion. 3. The method of claim 2,
And the mixture is dispersed by wet milling. The method of claim 2, wherein the first dispersant comprises
And adding the polyacrylic acid amine salt having the molecular weight of 5000 to the indium oxide powder 100 weight ratio so as to add 1.0 weight of the IGZO target. 3. The composition of claim 2, wherein the second dispersant comprises
Wherein the polyacrylic acid amine salt having a molecular weight of 3000 relative to the gallium oxide powder 100 weight ratio is added so as to add 0.5 weight of the gallium oxide powder. 3. The composition of claim 2, wherein the third dispersant comprises
Wherein the polyacrylic acid amine salt having a molecular weight of 2000 relative to the gallium oxide powder 100 weight ratio is added so as to add 1.0 weight of the gallium oxide. delete The method according to claim 1, wherein the binder
A method for producing an IGZO target, characterized by using polyvinyl acetate (PVA). 2. The method of claim 1,
Wherein the primary molding is performed by a cold press method and the secondary molding is performed by cold isostatic pressing.
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