KR20150023832A - Igzo sputtering target and igzo film - Google Patents

Abstract

Ga, Zn is 0.575? In / (In + Ga)? 0.500, and Zn / (In + Ga) is a sputtering target of IGZO sintered body made of indium (In), gallium (Ga), zinc (Zn) in + Ga + Zn) <a composition range of _{0.333, (in x Ga (1} -x)) 2 ZnO 4 (1>x> 0) has a single organization on the formed onto, or _{(in x} Ga _{(1 -x)} ) ₂ ZnO ₄ (1>x> 0) phase and an In ₂ O ₃ phase, and the maximum diameter of the In ₂ O ₃ phase is 10 μm or less. A low bulk resistance of the target for sputtering and an IGZO target technique capable of performing DC sputtering while keeping the carrier concentration below a certain range and achieving high densification of the target and minimizing occurrence of arcing.

Description

IGZO Sputtering Target and IGZO Film {IGZO SPUTTERING TARGET AND IGZO FILM}

The present invention relates to an IGZO target suitable for use in producing a transparent semiconductor IGZO film used for an active layer of a thin film transistor or the like in a liquid crystal display device or an organic EL display device by a sputtering method and an IGZO film obtained by sputtering the target.

Though thin-film transistors each having an active layer of a silicon-based material for pixel driving are used for display elements such as active matrix type liquid crystal display devices, reduction of the aperture ratio due to an increase in the occupied area of the transistors accompanying pixel refinement, A thin film transistor using a transparent oxide semiconductor has recently been developed.

The transparent oxide semiconductors are attracting attention from the viewpoints of uniformity of film formation over a large area by a sputtering method and high mobility. Among them, In-Ga-Zn-O-based materials (for example, indium, gallium, (Hereinafter referred to as &quot; IGZO &quot;) is higher than the mobility of amorphous silicon, and the field effect transistor using the amorphous IGZO film as an active layer has characteristics such as large on-off ratio and low off current value (Refer to Non-Patent Document 1 and Patent Document 1).

As a method for producing an amorphous IGZO film, a sputtering method excellent in mass productivity is most suitable, and the IGZO target needs to have a high density for this purpose.

However, in some cases, a high-density IGZO target can be produced. However, the density of the sintered body is lowered during the continuation of production, and if further production is continued, a high density target may be produced. The target manufacturing process condition of the target was inadequate, but the cause was unknown in some cases.

Patent Document 2 describes a method for producing an indium oxide-based sputtering target using indium oxide powder having a chlorine concentration of 50 mass ppm or less. However, what is disclosed in the specification is only the effect of the concentration of chlorine contained in the indium oxide powder. Patent Document 3 discloses an indium oxide powder sugar having a low halogen element content. However, in the embodiment, indium nitrate is used as a raw material.

In addition, in Patent Document 4, an oxide containing an indium element (In), a gallium element (Ga), and a zinc element (Zn) and including an oxide crystal phase represented by (Ga, In) ₂ O ₃ . Wherein the oxide crystal phase represented by (Ga, In) ₂ O ₃ is at least 50 mass% with respect to the entire crystal phase contained in the oxide. The ratio of the atomic ratio of each element to the sum (In + Ga + Zn) of indium element (In), gallium element (Ga) and zinc element (Zn) satisfies the following formulas (1) .

0.05? In / (In + Ga + Zn)? 0.9 (1)

0.05? Ga / (In + Ga + Zn)? 0.9 (2)

0.05? Zn / (In + Ga + Zn)? 0.9 (3)

Patent Document 5 discloses a sputtering target containing an oxide A shown below and indium oxide (In ₂ O ₃ ) having a crystal structure of a Bix (registered trademark) byte type. An oxide A contains indium element (In), gallium element (Ga) and zinc element (Zn), and has an incident angle (2θ) of 7.0 ° to 8.4 °, 30.6 ° to 32.0 ° Deg.], 33.8 [deg.] To 35.8 [deg.], 53.5 [deg.] To 56.5 [deg.] And 56.5 [deg.] To 59.5 [deg.]. Wherein the atomic ratio of the indium element (In), the gallium element (Ga) and the zinc element (Zn) satisfies the following formulas (1) and (2).

0.10? Zn / (In + Ga + Zn)? 0.45 (1)

0.05 &lt; Ga / (In + Ga + Zn) &lt; 0.18 (2)

Further, the atomic ratio of the indium element (In) and the gallium element (Ga) satisfies the following formula (3).

0.14 &lt; Ga / (In + Ga) (3) &quot;

However, although they have a wide composition of the target composition, there is a problem that the effect of suppressing the abnormal discharge is small because the crystal structure (phase) of the target is not sufficiently adjusted.

Japanese Laid-Open Patent Publication No. 2006-173580 Japanese Patent Application Laid-Open No. 2008-308385 Japanese Patent Application Laid-Open No. 10-182150 Japanese Laid-Open Patent Publication No. 2009-275272 Japanese Laid-Open Patent Publication No. 2011-106002

Non-Patent Document 1: K. Nomura et al. "Room-temperature fabrication of transparent flexible thin-film transistors using amorphous oxide semiconductors", Nature, 432, p488-492 (2004)

DISCLOSURE OF THE INVENTION The present invention has been made in view of such circumstances, and an object of the present invention is to provide a high density IGZO target as a sputtering target required for film formation in a sputtering method of a transparent semiconductor IGZO film and to provide a low bulk resistance of a sputtering target, An object of the present invention is to provide an IGZO target technology capable of DC sputtering by keeping the carrier concentration and mobility in a constant range and suppressing arcing to a minimum.

Based on these findings, the present invention provides the following inventions.

1) An IGZO sintered product sputtering target comprising indium (In), gallium (Ga), zinc (Zn) and oxygen (O), wherein the ratio of In, Ga and Zn is 0.575 ≥ In / (In + Ga) / (In + Ga + Zn) &lt; 0.333, and has a single phase structure composed of (In _x Ga _(1-x) ) ₂ ZnO ₄ (1>x> 0) phases.

2) An IGZO sintered sputtering target comprising indium (In), gallium (Ga), zinc (Zn) and oxygen (O), wherein the ratio of In, Ga and Zn is 0.575 ≥ In / (In + Ga) Phase structure composed of (In _x Ga _(1-x) ) ₂ ZnO ₄ (1>x> 0) phase and In ₂ O ₃ phase and having a composition range of (In + Ga + Zn) <0.333 , And the maximum diameter of the In ₂ O ₃ phase is not more than 10 탆.

3) The sputtering target according to the above 1) or 2), wherein the bulk resistance is 15 m? 占 ㎝ m or less.

4) The sputtering target according to any one of 1) to 3) above, wherein the relative density is 95% or more.

(5) A film obtained by sputtering using the sputtering target according to any one of (1) to (4) above, characterized by having a film characteristic with a carrier concentration of 5 x 10 ¹⁵ (cm ^-3 ) or less and a mobility of 5 &Lt; / RTI &gt;

As described above, according to the present invention, the high-density IGZO oxide sintered body used as a sputtering target for producing a transparent semiconductor IGZO film can provide a high-density IGZO target, and can realize a low bulk resistance of the sputtering target, It is possible to provide an IGZO target technology capable of DC sputtering while minimizing the occurrence of arcing and to provide an IGZO target technology capable of being an active layer portion of a thin film transistor in an active matrix driven liquid crystal display element or an organic EL display element It is possible to produce a good transparent semiconductor IGZO film with high quality and efficiency.

The oxide sintered body used in the present invention contains indium (In), gallium (Ga), zinc (Zn) and oxygen (O) as constituent elements. By controlling the composition of the target, the bulk resistance and the structure, the oxygen partial pressure at the time of film formation is reduced to obtain a predetermined film characteristic (carrier concentration, mobility). The IGZO film has a lower carrier concentration in the film as the oxygen partial pressure during film formation increases.

In order to obtain semiconductor characteristics, a carrier concentration of 10 ¹⁵ (cm ^-3 ) or less is required, and oxygen is required to be introduced at the time of film formation in order to obtain this. As the oxygen partial pressure increases, negative factors such as lowering of the sputter rate and destabilization of the plasma occur, so that the oxygen partial pressure is preferably low.

The IGZO sputtering target made of indium (In), gallium (Ga), zinc (Zn), and oxygen (O) of the present invention has In, Ga and Zn other than oxygen satisfying 0.575? In / (In + Ga)? 0.500 , And Zn / (In + Ga + Zn) &lt; 0.333.

The present invention is an improvement of an IGZO target having a composition of In: Ga: Zn = 1: 1: 1, which can provide a high-density IGZO target and can realize a low bulk resistance of a target for sputtering, The DC sputtering can be performed with a constant range of the degree of suppression of arc generation.

Here, when the amount of In becomes large, the In ₂ O ₃ phase grows remarkably, and a large abnormal phase having different electric characteristics is present in the IGZO phase, leading to an abnormal discharge. When the amount of In is large, the carrier concentration in the film tends to increase. In order to obtain a film with a low carrier concentration, a large amount of oxygen is required to be introduced at the time of film formation, and plasma in the sputter becomes unstable. On the other hand, if the In content is too small, the mobility of the film is insufficient.

It is necessary to control the In composition in the present specification in order to secure a predetermined mobility while avoiding abnormalities during sputtering.

When Ga is increased, the target density is not increased and the conductivity is also deteriorated. In addition, if Ga and Zn are excessively increased, the mobility of the resulting film is remarkably lowered, and therefore it is necessary to control the composition of Ga and Zn. The above-mentioned composition range is adjusted to a range in which these problems can be solved, and this is an essential requirement of the present invention.

Further, IGZO target of the present _{invention, (In x Ga (1-} x)) 2 ZnO 4 (1>x> 0) sangman, or _{(In x Ga (1-x} )) 2 ZnO 4 (1>x> 0) the addition, and some containing in ₂ O ₃ phase is also a bulk resistivity less than 15 mΩ · ㎝ one of the main feature.

The sputtering target has a structure in which the maximum diameter of the In ₂ O ₃ phase is not more than 10 탆, and the relative density is not less than 95%.

An IGZO film having a carrier concentration of 5 x 10 ¹⁵ (cm ^-3 ) or less and a film property of 5 (cm 2 / Vs) or more in mobility can be obtained by sputtering using this IGZO sputtering target. These conditions can be set as needed according to the purpose of improving the characteristics.

As described above, the relative density of the oxide-sintered body of the present invention can be 95% or more, 98% or more, and 99% or more. If the relative density of the oxide-sintered body is less than 95%, in addition to a large variation in the carrier concentration of the film, in the case where the oxide-sintered body is sputtered by using the oxide-sintered body as a sputtering target, arcing accompanies with the passage of the sputtering time, There is a disadvantage that the obtained film characteristics are deteriorated, so that the superiority of the present invention is evident.

In the method of measuring the relative density of the oxide-sintered body, it is possible to first determine the value of the density at which the relative density of the oxide-sintered body becomes 100% from each constituent element and shape for each composition, Archimedes' method or the like, and dividing the value by the density of the relative density of 100%.

Measurement of particle size of the In ₂ O ₃ to be contained in the oxide sintered body, and by a reflection electron image of SEM, In ₂ O ₃ each of In ₂ O ₃ by an image analysis from tissue picture containing a different measure the diameter is maximum , And the maximum diameter of one field of view was obtained. This was measured randomly at 5 o'clock, and the maximum value among them was defined as the maximum diameter.

The sputter voltage at the time of film formation can be lowered by the low bulk resistance of the target of the present invention. When the sputter voltage is high, the film formed by the secondary ions or high energy scattering particles generated by the sputter is impacted, causing damage and causing a lot of oxygen deficiency.

In the sputtering of an oxide semiconductor, it is necessary to supply a large amount of oxygen to the deposition atmosphere in order to reduce the amount of oxygen deficiency and obtain a predetermined carrier concentration. However, by reducing the sputter voltage by lowering the resistance of the target to a low bulk resistance, The oxygen partial pressure in the sputter necessary for obtaining a predetermined carrier concentration can be reduced.

The size of the In ₂ O ₃ phase can be controlled by the composition of the components and the sintering temperature. That is, the higher the In concentration, the more easily the In ₂ O ₃ phase grows, and the higher the In concentration, the larger the size of the In ₂ O ₃ phase can be controlled. The sintering temperature is preferably 1420 DEG C or more and 1480 DEG C or less. If the sintering temperature is excessively increased, coarsening of the In ₂ O ₃ phase occurs to increase the arcing number, which is not preferable.

(Manufacturing method of oxide-sintered body)

Typical examples of the production process of the oxide-sintered body according to the present invention are as follows.

As the raw material, indium oxide (In ₂ O ₃ ), gallium oxide (Ga ₂ O ₃ ) and zinc oxide (ZnO) can be used. It is preferable to use a raw material having a purity of 4 N or more in order to avoid an adverse influence on the electric characteristics due to impurities. Each raw material powder is weighed to a desired composition ratio. In addition, as described above, impurities inevitably contained therein are included.

Next, mixing and grinding are carried out. When the pulverization is insufficient, each component is segregated in the produced target, so that a high-resistivity region and a low-resistivity region are present, which causes an abnormal discharge such as arcing due to charging in a high resistivity region at the time of sputtering, And grinding is necessary.

The production of the target is carried out by calcining the raw material as necessary. After mixing the raw materials with a super mixer, they are filled in an alumina mortar if necessary and preheated at a temperature of 950 to 1350 ° C. The holding time of the plasticizer is 2 to 10 hr, in an oxygen atmosphere or an air atmosphere.

In the case of a small amount of the mixed raw material, for example, 1 kg of an agitator (3 mm zirconia beads, agitator rotation speed of 300 rpm) or LMZ (star mill: manufactured by Ashizawa Fine Tech) And pulverized for 2 to 5 hr.

In the case of a large quantity, the raw material is pulverized (φ 0.5 mm zirconia beads, input power 2.0 to 20.0 ㎾ · kW) in a batch of 20 to 1000 kg in an amount of 2 to 8 hr with LMZ (Styler: Hr).

Next, the slurry after the pulverization is added with a binder, dried at 100 to 250 ° C by a granulator, and sieved with a mesh of 250 μm sieve to recover the powder. The specific surface area of each powder is measured before and after the fine pulverization. 1000 g of IGZO powder is mixed with 50 to 200 cc of PVA aqueous solution (PVA solid content 6%).

Next, 1000 g of powder is charged into a mold having a diameter of 210 mm and pressed at a surface pressure of 400 to 1000 kgf · cm 2 to obtain a molded article. This molded article is vacuum packed with two layers of vinyl, and is subjected to CIP at 1500 to 4000 kgf / cm 2. Then, sintering is performed at a predetermined temperature (holding time: 5 to 24 hr, in an oxygen atmosphere) to obtain a sintered body.

In the production of the target, cylindrical grinding of the outer periphery of the oxide-sintered body obtained by the above, and surface grinding of the surface side are machined into, for example, a target of 152.4? 占 5 tmm. Again, for example, an indium-based alloy or the like is bonded to a backing plate made of copper by bonding to form a sputtering target.

Example

The following is a description based on examples and comparative examples. The present embodiment is merely an example, and is not limited by this example. That is, the present invention is limited only by the claims, and includes various modifications other than the embodiments included in the present invention.

The raw material powders used in the examples are shown in Table 1. (In + Ga + Zn) &lt; 0.333 with In / Ga + Zn as the metal ratio except for oxygen is set to be 0.575, and the remainder is made Ga so that the composition becomes Ga And various combinations of these raw materials and manufacturing conditions (fine pulverization, calcination temperature, sintering temperature) were changed to produce a target, and various tests were conducted. Details of these are shown in Examples 1 to 7 of Table 1.

In the following examples and comparative examples, various analytical measurements and evaluations are required. The conditions, device names and the like are shown below.

(Measurement of average particle diameter of raw material)

The particle size was measured using a particle size distribution measuring apparatus (Microtrac MT3000, manufactured by Nikkiso Co., Ltd.).

(Measurement of density)

The density was measured by the Archimedes method using pure water as a solvent. The theoretical density used for the calculation of the relative density was calculated from the weight ratio of each raw material (In ₂ O ₃ : 7.18 g / cm 3, Ga ₂ O ₃ : 6.44 g / cm 3, and ZnO: 5.61 g / Respectively.

(Measurement of Bulk Resistance Value)

The bulk resistance value was measured by a 4-probe method using a resistivity meter (manufactured by NPS, Σ-5 +).

(Sputtering condition)

A DC magnetron sputtering apparatus was used as the sputtering apparatus. Conditions for forming the film were room temperature, DC 500 W, oxygen concentration of 6% and annealing conditions at 300 ° C for 1 hour in an atmospheric environment.

The carrier concentration and the mobility of the film were measured using a ResiTest 8400 Hall effect measuring apparatus manufactured by Toyota Technica. A carrier concentration of 5 x 10 ¹⁵ (cm ^-3 ) or less and a mobility of 5 (cm 2 / Vs) or more.

(Example 1)

In ₂ O particle size as the _third raw material 1.3 ㎛, a specific surface area (BET) 4.4 ㎡ / g of In ₂ O _3, and using the powder, Ga ₂ O particle size as the _third raw material 5.6 ㎛, a specific surface area of 9.1 ㎡ / g of Ga ₂ O ₃ ZnO powder having a particle size of 1.1 mu m and a specific surface area of 3.8 m &lt; 2 &gt; / g was used as a ZnO raw material. These powders were prepared by adjusting In, Ga and Zn to a total of 100 wt% by adjusting the content of In ₂ O ₃ raw material to 46.6 wt%, Ga ₂ O ₃ raw material to 28.6 wt% and ZnO raw material to 24.8 wt% In / (In + Ga) is 0.524, Zn / (In + Ga + Zn) is 0.323, and the rest is Ga.

Next, these powders were mixed (not plasticized). The specific surface area before pulverization was 6.0 m &lt; 2 &gt; / g. The specific surface area after grinding was 17.8 m &lt; 2 &gt; / g. This difference was 11.8 m &lt; 2 &gt; / g. The sintering temperature of the powder was sintered at 1430 ° C and sintering atmosphere: oxygen atmosphere.

As a result, the bulk density was 6.32 g / cm 3, the relative density was 96.8%, the bulk density was 3.8 mΩ · cm, and the bulk resistance value was enough for DC sputtering. (In _x Ga _(1-x) ) ₂ ZnO ₄ phase and In ₂ O ₃ phase 2 phase. The maximum size of In ₂ O ₃ phase (long diameter) was 4.9 μm.

The carrier concentration was 2.21 x 10 ¹⁵ (cm ^-3 ) and the mobility was 9.14 (cm 2 / Vs). In addition, arc generation during sputtering was reduced to 121 cycles. All satisfied the conditions of the present invention.

(Example 2)

Using the particle size of 1.3 ㎛, a specific surface area of 4.4 ㎡ / g of In ₂ using O ₃ powder, Ga ₂ O particle size as the _third raw material 5.6 ㎛, a specific surface area of 9.1 ㎡ / g Ga ₂ O ₃ powder as the In ₂ O ₃ raw material ZnO powder having a particle size of 1.1 m and a specific surface area of 3.8 m &lt; 2 &gt; / g was used as a ZnO raw material.

These powders were adjusted to have a total of 100 wt% by adjusting the contents of In ₂ O ₃ , Ga ₂ O ₃ , and ZnO to 44.7 wt%, 29.6 wt%, and 25.7 wt%, respectively, In / (In + Ga) is 0.505, Zn / (In + Ga + Zn) is 0.331, and the rest is Ga.

Next, these powders were mixed (not plasticized). The specific surface area before pulverization was 6.0 m &lt; 2 &gt; / g. The specific surface area after grinding was 18.0 m 2 / g. This difference was 12.0 m &lt; 2 &gt; / g. The sintering temperature of the powder was sintered at 1430 ° C and sintering atmosphere: oxygen atmosphere.

As a result, the bulk density was 6.33 g / cm 3, the relative density was 97.3%, the bulk density was 5.8 mΩ · cm, and the bulk resistance value was enough for DC sputtering. The phase state was a single phase of (In _x Ga _(1-x) ) ₂ ZnO ₄ phase.

The carrier concentration was 1.34 × 10 ¹⁵ (cm ^-3 ) and the mobility was 6.46 (cm 2 / Vs). Incidentally, arc generation during sputtering was reduced to 86 cycles. All satisfied the conditions of the present invention.

(Example 3)

Using the particle size of 1.3 ㎛, a specific surface area of 4.4 ㎡ / g of In ₂ using O ₃ powder, Ga ₂ O particle size as the _third raw material 5.6 ㎛, a specific surface area of 9.1 ㎡ / g Ga ₂ O ₃ powder as the In ₂ O ₃ raw material ZnO powder having a particle size of 1.1 m and a specific surface area of 3.8 m &lt; 2 &gt; / g was used as a ZnO raw material.

These powders were adjusted to a total of 100 wt% by adjusting the content of In ₂ O ₃ raw material to 45.4 wt%, the Ga ₂ O ₃ raw material to 29.2 wt% and the ZnO raw material to 25.4 wt% (In + Ga) is 0.512, Zn / (In + Ga + Zn) is 0.328, and the rest is Ga.

Next, these powders were mixed (not plasticized). The specific surface area before pulverization was 5.8 m &lt; 2 &gt; / g. The specific surface area after grinding was 16.8 m &lt; 2 &gt; / g. This difference was 11.0 m 2 / g. The sintering temperature of the powder was sintered at 1430 ° C and sintering atmosphere: oxygen atmosphere.

As a result, the density was 6.33 g / cm 3, the relative density was 97.1%, the density was high, and the bulk resistance value was 4.3 m? 占 ㎝ m, which had a low bulk resistance value enough for DC sputtering. The maximum size (long diameter) of the In ₂ O ₃ phase was 5.2 μm, and the phase state was (In _x Ga _(1-x) ) ₂ ZnO ₄ phase and In ₂ O ₃ phase 2 phase.

The carrier concentration was 1.56 x 10 ¹⁵ (cm ^-3 ) and the mobility was 7.23 (cm 2 / Vs). In addition, generation of arcing during sputtering was reduced to 130 cycles. All satisfied the conditions of the present invention.

(Example 4)

Using the particle size of 1.3 ㎛, a specific surface area of 4.4 ㎡ / g of In ₂ using O ₃ powder, Ga ₂ O particle size as the _third raw material 5.6 ㎛, a specific surface area of 9.1 ㎡ / g Ga ₂ O ₃ powder as the In ₂ O ₃ raw material ZnO powder having a particle size of 1.1 m and a specific surface area of 3.8 m &lt; 2 &gt; / g was used as a ZnO raw material.

These powders were prepared by adjusting In, Ga and Zn to a total of 100 wt% by adjusting the content of In ₂ O ₃ raw material to 46.6 wt%, Ga ₂ O ₃ raw material to 28.6 wt% and ZnO raw material to 24.8 wt% In / (In + Ga) is 0.524, Zn / (In + Ga + Zn) is 0.323, and the rest is Ga.

Next, these powders were mixed (not plasticized). The specific surface area before pulverization was 5.9 m &lt; 2 &gt; / g. The specific surface area after grinding was 17.5 m &lt; 2 &gt; / g. This difference was 11.6 m &lt; 2 &gt; / g. The sintering temperature of the powder was sintered at 1430 캜 in sintering atmosphere: air.

As a result, the bulk density was 6.32 g / cm 3, the relative density was 96.8%, the bulk density was 2.9 mΩ · cm, and the bulk resistance value was enough for DC sputtering. (In _x Ga _(1-x) ) ₂ ZnO ₄ phase and In ₂ O ₃ phase 2 phase. The maximum size of the In ₂ O ₃ phase (long diameter) was 4.3 μm.

The carrier concentration was 1.72 × 10 ¹⁵ (cm ^-3 ) and the mobility was 8.62 (cm 2 / Vs). In addition, arcing during sputtering was reduced to 128 cycles. All satisfied the conditions of the present invention.

(Example 5)

Using the particle size of 1.3 ㎛, a specific surface area of 4.4 ㎡ / g of In ₂ using O ₃ powder, Ga ₂ O particle size as the _third raw material 5.6 ㎛, a specific surface area of 9.1 ㎡ / g Ga ₂ O ₃ powder as the In ₂ O ₃ raw material ZnO powder having a particle size of 1.1 m and a specific surface area of 3.8 m &lt; 2 &gt; / g was used as a ZnO raw material.

These powders were prepared by adjusting In, Ga and Zn to a total of 100 wt% by adjusting the content of In ₂ O ₃ raw material to 46.6 wt%, Ga ₂ O ₃ raw material to 28.6 wt% and ZnO raw material to 24.8 wt% In / (In + Ga) is 0.524, Zn / (In + Ga + Zn) is 0.323, and the rest is Ga.

Next, these powders were mixed (not plasticized). The specific surface area before pulverization was 5.9 m &lt; 2 &gt; / g. The specific surface area after grinding was 17.5 m &lt; 2 &gt; / g. This difference was 11.6 m &lt; 2 &gt; / g. The sintering temperature of the powder was sintered at 1370 캜 and sintering atmosphere: oxygen atmosphere.

As a result, the bulk density was 6.32 g / cm 3, the relative density was 96.8%, the bulk density was 8.0 mΩ · cm, and the bulk resistance value was enough for DC sputtering. The maximum size (long diameter) of the In ₂ O ₃ phase was 3.5 μm, and the phase state was (In _x Ga _(1-x) ) ₂ ZnO ₄ phase and In ₂ O ₃ phase 2 phase.

The carrier concentration was 2.61 × 10 ¹⁵ (cm ^-3 ) and the mobility was 8.89 (cm 2 / Vs). Incidentally, arcing during sputtering was reduced to 142 cycles. All satisfied the conditions of the present invention.

(Example 6)

Using the particle size of 1.3 ㎛, a specific surface area of 4.4 ㎡ / g of In ₂ using O ₃ powder, Ga ₂ O particle size as the _third raw material 5.6 ㎛, a specific surface area of 9.1 ㎡ / g Ga ₂ O ₃ powder as the In ₂ O ₃ raw material ZnO powder having a particle size of 1.1 m and a specific surface area of 3.8 m &lt; 2 &gt; / g was used as a ZnO raw material.

These powders were prepared by adjusting In, Ga and Zn to a total of 100 wt% by adjusting the contents of 49.9 wt% of In ₂ O ₃ raw material, 24.9 wt% of Ga ₂ O ₃ raw material and 25.3 wt% of ZnO raw material, In / (In + Ga) is 0.575, Zn / (In + Ga + Zn) is 0.332, and the rest is Ga.

Next, these powders were mixed (not plasticized). The specific surface area before pulverization was 5.6 m &lt; 2 &gt; / g. The specific surface area after grinding was 17.8 m &lt; 2 &gt; / g. This difference was 12.2 m &lt; 2 &gt; / g. The sintering temperature of the powder was sintered at 1430 ° C and sintering atmosphere: oxygen atmosphere.

As a result, the bulk density was 6.38 g / cm 3, the relative density was 97.5%, the bulk density was 9.8 mΩ · cm, and the bulk resistance value was enough for DC sputtering. The phase state was a single phase of (In _x Ga _(1-x) ) ₂ ZnO ₄ phase.

The carrier concentration was 3.53 x 10 ¹⁵ (cm ^-3 ) and the mobility was 9.53 (cm 2 / Vs). Incidentally, generation of arcing during sputtering was reduced to 134 cycles. All satisfied the conditions of the present invention.

(Example 7)

Using the particle size of 1.3 ㎛, a specific surface area of 4.4 ㎡ / g of In ₂ using O ₃ powder, Ga ₂ O particle size as the _third raw material 5.6 ㎛, a specific surface area of 9.1 ㎡ / g Ga ₂ O ₃ powder as the In ₂ O ₃ raw material ZnO powder having a particle size of 1.1 m and a specific surface area of 3.8 m &lt; 2 &gt; / g was used as a ZnO raw material.

These powders were prepared by adjusting In, Ga, and Zn to a total of 100 wt% by adjusting the content of In ₂ O ₃ raw material to 52.4 wt%, Ga ₂ O ₃ raw material to 26.2 wt%, and ZnO raw material to 21.4 wt% In / (In + Ga) is 0.575, Zn / (In + Ga + Zn) is 0.286, and the rest is Ga.

Next, these powders were mixed (not plasticized). The specific surface area before pulverization was 6.2 m 2 / g. The specific surface area after grinding was 15.5 m &lt; 2 &gt; / g. This difference was 9.3 m &lt; 2 &gt; / g. The sintering temperature of the powder was sintered at 1430 ° C and sintering atmosphere: oxygen atmosphere.

As a result, the density was 6.42 g / cm 3, the relative density was 97.2%, the density was high, and the bulk resistance value was 2.1 m? 占 ㎝ m, and had a low bulk resistance value sufficient for DC sputtering. The maximum size (long diameter) of the In ₂ O ₃ phase was 8.8 μm, and the phase state was (In _x Ga _(1-x) ) ₂ ZnO ₄ phase and In ₂ O ₃ phase 2 phase.

The carrier concentration was 4.55 × 10 ¹⁵ (cm ^-3 ) and the mobility was 7.34 (cm 2 / Vs). In addition, arcing during sputtering was reduced to 173 circuits. All satisfied the conditions of the present invention.

(Comparative Example 1)

Using the particle size of 1.3 ㎛, a specific surface area of 4.4 ㎡ / g of In ₂ using O ₃ powder, Ga ₂ O particle size as the _third raw material 5.6 ㎛, a specific surface area of 9.1 ㎡ / g Ga ₂ O ₃ powder as the In ₂ O ₃ raw material ZnO powder having a particle size of 1.1 m and a specific surface area of 3.8 m &lt; 2 &gt; / g was used as a ZnO raw material.

These powders were prepared by adjusting In, Ga, and Zn to a total of 100 wt% by adjusting the content of In ₂ O ₃ raw material to 44.2 wt%, Ga ₂ O ₃ raw material to 29.9 wt%, and ZnO raw material to 25.9 wt% In / (In + Ga) is 0.500, Zn / (In + Ga + Zn) is 0.333, and the rest is Ga.

Next, these powders were mixed (not plasticized). The specific surface area before pulverization was 5.6 m &lt; 2 &gt; / g. The specific surface area after grinding was 16.6 m &lt; 2 &gt; / g. This difference was 11.0 m 2 / g. The sintering temperature of the powder was sintered at 1430 ° C and sintering atmosphere: oxygen atmosphere.

As a result, the density was 6.33 g / cm 3, the relative density was high at 97.3%, and the bulk resistance value was as high as 32 mΩ · cm, so DC sputtering was not sufficient. The phase state was a single phase of (In _x Ga _(1-x) ) ₂ ZnO ₄ phase.

Then, the carrier concentration was increased to 5.87 × 10 ¹⁵ (cm ^-3 ). The degree of mobility was 8.92 (cm2 / Vs). Incidentally, arcing during sputtering was reduced to 92 cycles. But did not satisfy the conditions of the present invention.

(Comparative Example 2)

Using the particle size of 1.3 ㎛, a specific surface area of 4.4 ㎡ / g of In ₂ using O ₃ powder, Ga ₂ O particle size as the _third raw material 5.6 ㎛, a specific surface area of 9.1 ㎡ / g Ga ₂ O ₃ powder as the In ₂ O ₃ raw material ZnO powder having a particle size of 1.1 m and a specific surface area of 3.8 m &lt; 2 &gt; / g was used as a ZnO raw material.

These powders were prepared by adjusting In, Ga and Zn to a total of 100 wt% by adjusting the content of In ₂ O ₃ raw material to 46.6 wt%, Ga ₂ O ₃ raw material to 28.6 wt% and ZnO raw material to 24.8 wt% In / (In + Ga) is 0.500, Zn / (In + Ga + Zn) is 0.333, and the rest is Ga.

Next, these powders were mixed (not plasticized). The specific surface area before pulverization was 5.6 m &lt; 2 &gt; / g. The specific surface area after grinding was 16.6 m &lt; 2 &gt; / g. This difference was 11.0 m 2 / g. The sintering temperature of the powder was sintered at 1370 캜 and sintering atmosphere: oxygen atmosphere.

As a result, the density was 6.32 g / cm 3, the relative density was high at 97.2%, and the bulk resistance value was as high as 80 mΩ · cm, so DC sputtering was not sufficient. The phase state was a single phase of (In _x Ga _(1-x) ) ₂ ZnO ₄ phase.

Then, the carrier concentration was increased to 10.8 × 10 ¹⁵ (cm ^-3 ). The mobility was 10.5 (cm 2 / Vs). In addition, arc generation during sputtering was reduced to 76 cycles. But did not satisfy the conditions of the present invention.

(Comparative Example 3)

Using the particle size of 1.3 ㎛, a specific surface area of 4.4 ㎡ / g of In ₂ using O ₃ powder, Ga ₂ O particle size as the _third raw material 5.6 ㎛, a specific surface area of 9.1 ㎡ / g Ga ₂ O ₃ powder as the In ₂ O ₃ raw material ZnO powder having a particle size of 1.1 m and a specific surface area of 3.8 m &lt; 2 &gt; / g was used as a ZnO raw material.

These powders were prepared by adjusting In, Ga, and Zn to a total of 100 wt% by adjusting the In ₂ O ₃ raw material to 61.7 wt%, the Ga ₂ O ₃ raw material to 16.7 wt%, and the ZnO raw material to 21.7 wt% In / (In + Ga) is 0.714, Zn / (In + Ga + Zn) is 0.333, and the rest is Ga.

Next, these powders were mixed (not plasticized). The specific surface area before grinding was 5.1 m &lt; 2 &gt; / g. The specific surface area after grinding was 16.0 m &lt; 2 &gt; / g. This difference was 10.9 m &lt; 2 &gt; / g. The sintering temperature of the powder was sintered at 1430 ° C and sintering atmosphere: oxygen atmosphere.

As a result, the bulk density was 6.55 g / cm 3, the relative density was 98.3%, the bulk density was 2.7 mΩ · cm, and the bulk resistance value was enough for DC sputtering. The maximum size (long diameter) of the In ₂ O ₃ phase was increased to 11.1 μm, and the phase state was (In _x Ga _(1-x) ) ₂ ZnO ₄ phase and In ₂ O ₃ phase 2 phase.

Then, the carrier concentration was increased to 1.15 × 10 ¹⁹ (cm ^-3 ). The degree of mobility was 29.0 (cm 2 / Vs). In addition, arcing occurred during sputtering in 366 cycles. This is a result that the In ₂ O ₃ phase was enlarged and did not satisfy the condition of the present invention.

(Comparative Example 4)

Using the particle size of 1.3 ㎛, a specific surface area of 4.4 ㎡ / g of In ₂ using O ₃ powder, Ga ₂ O particle size as the _third raw material 5.6 ㎛, a specific surface area of 9.1 ㎡ / g Ga ₂ O ₃ powder as the In ₂ O ₃ raw material ZnO powder having a particle size of 1.1 m and a specific surface area of 3.8 m &lt; 2 &gt; / g was used as a ZnO raw material.

These powders were prepared by adjusting In, Ga, and Zn to a total of 100 wt% by adjusting the content of In ₂ O ₃ raw material to 52.4 wt%, Ga ₂ O ₃ raw material to 26.2 wt%, and ZnO raw material to 21.4 wt% In / (In + Ga) is 0.575, Zn / (In + Ga + Zn) is 0.286, and the rest is Ga.

Next, these powders were mixed (not plasticized). The specific surface area before pulverization was 6.2 m 2 / g. The specific surface area after grinding was 15.5 m &lt; 2 &gt; / g. This difference was 9.3 m &lt; 2 &gt; / g. The sintering temperature of the powder was sintered at 1490 캜 in sintering atmosphere: oxygen atmosphere.

As a result, the density was 6.43 g / cm 3, the relative density was 97.4%, the bulk density was 1.2 mΩ · cm, and the bulk resistance value was enough for DC sputtering. The maximum size (long diameter) of the In ₂ O ₃ phase became 13.5 탆, and the phase state was (In _x Ga _(1-x) ) ₂ ZnO ₄ phase and In ₂ O ₃ phase 2 phase.

The carrier concentration was 4.55 × 10 ¹⁵ (cm ^-3 ) and the mobility was 7.34 (cm 2 / Vs). In addition, arcing occurred during sputtering in 514 cycles. This is because the In ₂ O ₃ phase is enlarged, and the conditions of the present invention are not satisfied.

Compared with Example 7, the composition was the same. In Comparative Example 4, coarsening of In ₂ O ₃ was observed. This is thought to be due to the coarsening of the In ₂ O ₃ phase because the sintering temperature was as high as 1430 ° C in Example 7 and 1490 ° C in Comparative Example 4.

(Comparative Example 5)

In ₂ O ₃ powder having a particle diameter of 10.7 μm and a specific surface area of 4.4 m 2 / g was used as a raw material of In ₂ O ₃ and Ga ₂ O ₃ powder having a particle diameter of 5.6 μm and a specific surface area of 9.1 m 2 / g was used as a raw material of Ga ₂ O ₃ ZnO powder having a particle size of 1.1 m and a specific surface area of 3.8 m &lt; 2 &gt; / g was used as a ZnO raw material.

These powders were adjusted to have a total of 100 wt% by adjusting the content of In ₂ O ₃ raw material to 42.9 wt%, Ga ₂ O ₃ raw material to 31.9 wt% and ZnO raw material to 25.2 wt% In / (In + Ga) is 0.476, Zn / (In + Ga + Zn) is 0.323, and the rest is Ga.

Next, these powders were mixed (not plasticized). The specific surface area before pulverization was 6.9 m &lt; 2 &gt; / g. The specific surface area after the pulverization was 18.7 m &lt; 2 &gt; / g. This difference was 11.8 m &lt; 2 &gt; / g. The sintering temperature of the powder was sintered at 1430 ° C and sintering atmosphere: oxygen atmosphere.

As a result, the density was 5.60 g / cm &lt; 3 &gt; and the relative density was 86.5%, which resulted in low density, and thus no DC sputtering was performed. The phase state was a single phase of (In _x Ga _(1-x) ) ₂ ZnO ₄ phase. Since the sputtering was not performed, the characteristics of the thin film could not be evaluated.

Industrial availability

The high density IGZO oxide sintered body used as the sputtering target for the transparent semiconductor IGZO film production of the present invention can provide a high density IGZO target and can realize a low bulk resistance of the sputtering target and a carrier concentration and mobility of the sputter film within a certain range In addition, it is possible to provide an IGZO target technology capable of DC sputtering by minimizing the occurrence of arcing, thereby achieving stable DC sputtering. Thereby, the target life can be made long, and the quality can be improved and the quality can be improved. This In-Ga-Zn-O-based (IGZO) material is useful for a field-effect transistor because an amorphous oxide having an electron carrier concentration of less than 10 ¹⁸ / cm 3 is obtained. In addition, the IGZO target can be used in a wide range of applications without hindrance, and thus the industrial utility value is high.

Claims (5)

Ga, Zn is 0.575? In / (In + Ga)? 0.500, and Zn / (In + Ga) is a sputtering target of IGZO sintered body made of indium (In), gallium (Ga), zinc (Zn) in + Ga + Zn) <a composition range of _{0.333, (in x Ga (1} -x)) 2 ZnO 4 (1>x> 0) , characterized in that the sputtering target having a structure composed of a single phase to phase. Ga, Zn is 0.575? In / (In + Ga)? 0.500, and Zn / (In + Ga) is a sputtering target of IGZO sintered body made of indium (In), gallium (Ga), zinc (Zn) in + Ga + Zn) <a composition range of _{0.333, (in x Ga (1} -x)) 2 ZnO 4 (1>x> 0) having a structure of phase and two-phase structure composed of in ₂ O ₃ phase, Wherein the maximum diameter of the In ₂ O ₃ phase is 10 μm or less. 3. The method according to claim 1 or 2,
And the bulk resistance is 15 m? 占 ㎝ m or less. 4. The method according to any one of claims 1 to 3,
And a relative density of 95% or more. A film obtained by sputtering using the sputtering target according to any one of claims 1 to 4 and having a film characteristic of a carrier concentration of 5 x 10 ¹⁵ (cm ^-3 ) or less and a mobility of 5 (cm 2 / Vs) or more &Lt; / RTI &gt;