Indium zinc tin oxide sputtering target material and indium zinc tin oxide conductive film formed thereby

Abstract

To provide an indium tin zinc oxide sputtering target material that can form a conductive film having flexibility.SOLUTION: An indium tin zinc oxide sputtering target material is a sintered body composed of In, Zn, Sn and O, wherein the sintered body is formed from In2O3 crystal phase and Zn3In2O6 crystal phase. With the total content of In, Zn, Sn as 100 at%, the content of In is 77 at%-90 at%. The ratio of the Zn content to the In content is more than 0.05.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to sputtering target materials, and more particularly to indium zinc tin sputtering target materials and indium zinc tin conductive films formed thereby. [Background technology]

[0002] Indium tin oxide (ITO) is a transparent conductive oxide (TCO) composed of In-Sn-O. Commercially available indium tin oxide (ITO) thin films with a thickness of 130 nm exhibit low resistivity (1.89 × 10⁻¹⁶). -4 Due to its excellent properties such as Ω-cm density and high transmittance (approximately 93.9% at a wavelength of 550nm), ITO is widely used as a transparent electrode in electronics industries such as displays, solar cells, light-emitting diodes (LEDs), and organic light-emitting diodes (OLEDs). In the aforementioned industries, sputtering is often used as a method for depositing ITO thin films. However, the crystal temperature of ITO thin films is low, between 150°C and 200°C, and if the ambient temperature rises above the crystal temperature of the ITO thin film during the manufacturing of electronic devices, the ITO thin film will form a crystalline structure. For this reason, ITO thin films are unsuitable for the manufacture of electronic devices that require flexibility.

[0003] Furthermore, with the widespread use of electronic devices, modern people spend more time looking at mobile phone and computer monitors, making the development of displays with blue light filtering capabilities a crucial point in the display field.

[0004] Reference 1 discloses a sputtering target material which is a sintered body composed of indium oxide (In2O3) powder, tin oxide (SnO2) powder, and zinc oxide (ZnO) powder. The document states that when the Zn atom content exceeds the Sn atom content, the resistivity of the metal oxide film formed by sputtering in the amorphous state is 3.9 × 10⁻⁶. -4 Ω-cm ~ 4.9 × 10 -4 Because it lies between Ω-cm and possesses excellent etching properties and light transmittance, it can be used as a substitute for ITO thin films. However, Reference 1 does not mention the flexibility or blue light filtering properties of the metal oxide film. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Taiwan Patent No. I437115 Publication [Overview of the project] [Problems that the invention aims to solve]

[0006] Therefore, improving the composition of the sputtering target material so that the TCO thin film formed by sputtering the sputtering target material meets the demands of the relevant industries not only in terms of resistivity but also in terms of flexibility is a challenge in this field of technology. [Means for solving the problem]

[0007] To achieve the above objective, the present invention is: A sintered body made of In, Zn, Sn, and O, The sintered body is composed of an In2O3 crystalline phase and a Zn3In2O6 crystalline phase. The present invention provides an indium zinc tin sputtering target material characterized in that, with a total content of In, Zn, and Sn of 100 at%, the In content is in the range of 77 at% to 90 at%, and the ratio of Zn content to In content is greater than 0.05.

[0008] Furthermore, a conductive film formed by the above-mentioned indium zinc tin sputtering target material has an electrical resistivity of 10 × 10 -4 The present invention provides an indium zinc tin oxide conductive film characterized by a density smaller than Ω-cm. [Effects of the Invention]

[0009] The present invention involves incorporating a sufficient amount of Zn into the sintered body of an indium zinc tin sputtering target material (the ratio of Zn content to In content exceeds 0.05, Zn / In > 0.05). As a result, the sintered body is composed of an In2O3 crystalline phase and a Zn3In2O6 crystalline phase. Therefore, the indium zinc tin oxide conductive film formed by this indium zinc tin sputtering target material has low electrical resistivity and excellent flexibility due to the Zn3In2O6 crystalline phase, which enhances the toughness and ductility of the conductive film. This makes it applicable to electronic equipment industries where flexibility is required. [Brief explanation of the drawing]

[0010] [Figure 1] This is an X-ray diffraction (XRD) diagram showing the crystal structure of Specific Example 2(E2) of the indium zinc tin sputtering target material of the present invention. [Figure 2] This is an XRD diagram showing the crystal structure of specific example 3(E3) of the indium zinc tin sputtering target material of the present invention. [Figure 3] This is an XRD diagram showing the crystal structure of specific example 4(E4) of the indium zinc tin sputtering target material of the present invention. [Figure 4]XRD diagram showing the crystal structure of the indium zinc tin oxide sputtering target material of Comparative Example 1 (CE1) of the present invention. [Figure 5] Optical microscope (abbreviation: OM) image of the conductive film according to Specific Example 3 (E3) of the indium zinc tin oxide sputtering target material of the present invention after static bending after annealing. [Figure 6] OM image of the conductive film made of the indium zinc tin oxide sputtering target material of Comparative Example 3 (CE3) of the present invention after static bending after annealing. [Figure 7] Graph showing the change (ΔR, %) of the electrical resistivity with the number of bending times of the conductive film according to Specific Example 3 (E3) of the indium zinc tin oxide sputtering target material of the present invention. [Figure 8] Graph showing the transmittance of light of different wavelengths of the conductive films according to Specific Examples 2, 3, 4 (E2, E3, E4) and Comparative Example 3 (CE3) of the indium zinc tin oxide sputtering target material of the present invention.

Mode for Carrying Out the Invention

[0011] As one embodiment of the present invention, the indium zinc tin oxide sputtering target material is a sintered body composed of In (indium), Zn (zinc), Sn (tin) and O (oxygen), and the sintered body is composed of an In2O3 crystal phase and a Zn3In2O6 crystal phase, and with respect to the total amount of 100 at% of the contents of In, Zn, and Sn, the content of In is within the range of 77 at% to 90 at%, and the ratio of the Zn content to the In content exceeds 0.05.

[0012] Based on the experience of the inventors of the present application in the development and research of TOC sputtering target materials for many years, in order to meet the needs in the electronics-related industries for the flexibility of indium zinc tin oxide conductive films formed by sputtering indium zinc tin oxide sputtering target materials, it has been found that the sputtering target material essentially needs to contain a sufficient amount of the Zn3In2O6 crystal phase that increases the toughness and ductility of the conductive film.

[0013] Based on this finding, as described above, the inventors of the present application have invented an indium zinc tin oxide sputtering target material in which, at a total content of In, Zn, and Sn of 100 at%, the ratio of the Zn content to the In content is controlled to exceed 0.05. In addition, the content of Zn is preferably within the range of 6.5 at% to 19 at%.

[0014] Specifically, the indium zinc tin oxide sputtering target material of the present invention is composed of sintering indium oxide (In2O3) powder, tin oxide (SnO2) powder, and zinc oxide (ZnO) powder. From the perspective of the sintering process, the content of In2O3 powder is between 84 wt% and 92 wt%, and the content of ZnO powder is between 3 wt% and 12 wt%.

[0015] In addition, if the content of Sn in the sintered body is too high, an unnecessary third phase, the Zn2SnO4 crystal phase, will occur in the sintered body, increasing the volume resistivity of the sintered body. In view of this problem, the inventors of the present application control the ratio of the In content to the Sn content to exceed 20 at a total content of In, Zn, and Sn of 100 at%, so that Sn atoms are completely dissolved in the In2O3 crystal phase, preventing the formation of a third phase that increases the volume resistivity of the sintered body.

[0016] Preferably, in the sintered body, the amount occupied by the Zn3In2O6 crystal phase is within the range of 1.5% to 7%.

[0017] More preferably, the relative density of the sintered body exceeds 99%, and the volume resistivity of the sintered body is 18 × 10⁻⁶. -4 It is smaller than Ω-cm.

[0018] More preferably, in the sintered body, the amount of Zn3In2O6 crystalline phase is in the range of 2% to 5%, and the volume resistivity of the sintered body is 14 × 10⁻⁶. -4 It is smaller than Ω-cm.

[0019] As one embodiment of the present invention, an indium zinc tin oxide conductive film is a conductive film formed by the above-mentioned indium zinc tin oxide sputtering target material, which is flexible and has an electrical resistivity of 10 × 10 -4 It is smaller than Ω-cm.

[0020] Preferably, the conductive film has an electrical resistivity of 5 × 10 -4 It is smaller than Ω-cm.

[0021] Preferably, when the conductive film has a thickness of 90 nm to 130 nm, it has flexibility such that the change in electrical resistivity (ΔR) after 200,000 repeated bends with a radius of curvature smaller than 3 mm is in the range of 1.0% to 10%.

[0022] Furthermore, in one embodiment of the present invention, when the indium zinc tin oxide conductive film has a thickness of 120 nm or more, the average transmittance of light with wavelengths of 415 nm to 455 nm is less than 85%.

[0023] Light with wavelengths of 415nm to 455nm is blue light, which is harmful to the human eye. Therefore, when the indium zinc tin oxide conductive film of the present invention is used as a transparent electrode layer in a flexible display, the average transmittance of blue light is less than 85%, thereby reducing damage to the human body caused by blue light.

[0024] The following describes specific examples of the present invention. It should be understood that these examples are illustrative and descriptive, and should not be interpreted as limiting the present invention.

[0025] <Method for manufacturing sputtering target material> <Specific Example 1 (E1)> The manufacturing method for Specific Example 1(E1) of the indium zinc tin oxide sputtering target material of the present invention comprises, in order, a first-stage wet ball milling step, a second-stage wet ball milling step, a granulating step, a molding step, and a sintering step.

[0026] In the first stage wet ball milling process, 84.0 wt% In2O3 powder, 12.0 wt% ZnO powder, 4.0 wt% SnO2 powder, and a predetermined amount of zirconium oxide (ZrO2) balls for the first stage wet ball milling process were placed into a ball mill machine (not shown) relative to the total weight of the sintered body of the indium zinc tin sputtering target material of Specific Example 1. During the ball milling process, a dispersant and pure water were continuously mixed in so that the powders were uniformly dispersed on the zirconium oxide balls, forming a low viscosity slurry of the powders with an average particle size of less than 1 μm. In the method for producing the indium zinc tin sputtering target material, which is Specific Example 1 of the present invention, the purity of the In2O3 powder, ZnO powder, and SnO2 powder is all higher than 3N (99.9%).

[0027] In the second stage wet ball milling process, an appropriate amount of adhesive was added to the low-viscosity slurry so that the powder would be uniformly ground into zirconium oxide balls, and after removing the zirconium oxide balls by filtration, a high-viscosity slurry was formed.

[0028] The granulation process involved using a spray granulator to dry the high-viscosity slurry into a powder, forming a large quantity of granulated powder with a diameter smaller than 100 μm.

[0029] The molding process involved sealing the granulated powder into a mold measuring 20 cm x 15 cm x 0.6 cm, and then applying a cold isostatic press (CIP) to the mold to form the granulated powder into a green body within the mold.

[0030] The aforementioned sintering process involved introducing the substrate into a sintering furnace containing oxygen and sintering the substrate at 1450°C for 15 hours to obtain a sintered body according to specific example 1(E1) of the present invention.

[0031] Based on a total weight of 100 wt% of the sintered body in Specific Example 1(E1), the total amount of In, Zn, and Sn content in Specific Example 1(E1) of the present invention is 100 at%, with an In content of 77.67 at%, a Zn content of 18.92 at%, a Sn content of 3.41 at%, and an In-to-Sn ratio (In / Sn) of 22.78, and a Zn-to-In ratio (Zn / In) of 0.24. Note that the at% values ​​obtained by conversion are rounded, so the sum of the In, Zn, and Sn content may not be 100 at%.

[0032] The specific composition and related analytical data of Specific Example 1 (E1) of the present invention are shown in Table 1 below.

[0033] <Specific Example 2 (E2)> The manufacturing method for Specific Example 2(E2) of the indium zinc tin oxide sputtering target material of the present invention is similar to the manufacturing method for Specific Example 1(E1), except that it uses 85.0 wt% In2O3 powder, 10.9 wt% ZnO powder, and 4.1 wt% SnO2 powder.

[0034] Based on a total weight of 100 wt% of the sintered body in Specific Example 2 (E2), the total amount of In, Zn, and Sn content in Specific Example 2 (E2) of the present invention is 100 at%, with an In content of 79.17 at%, a Zn content of 17.32 at%, a Sn content of 3.52 at%, and an In-to-Sn ratio (In / Sn) of 22.49, and a Zn-to-In ratio (Zn / In) of 0.22.

[0035] The specific composition and related analytical data of Specific Example 2(E2) of the present invention are shown in Table 1 below.

[0036] <Specific Example 3 (E3)> The manufacturing method for Specific Example 3 (E3) of the indium zinc tin oxide sputtering target material of the present invention is similar to the manufacturing method for Specific Example 1 (E1), except that it uses 89.0 wt% In2O3 powder, 6.9 wt% ZnO powder, and 4.1 wt% SnO2 powder.

[0037] Based on a total weight of 100 wt% of the sintered body in Specific Example 3 (E3), the total amount of In, Zn, and Sn content in Specific Example 3 (E3) of the present invention is 100 at%, with an In content of 85.13 at%, a Zn content of 11.26 at%, a Sn content of 3.61 at%, and an In-to-Sn ratio (In / Sn) of 23.58, and a Zn-to-In ratio (Zn / In) of 0.13.

[0038] The specific composition and related analytical data of Specific Example 3 (E3) of the present invention are shown in Table 1 below.

[0039] <Specific Example 4 (E4)> The manufacturing method for Specific Example 4(E4) of the indium zinc tin oxide sputtering target material of the present invention is similar to the manufacturing method for Specific Example 1(E1), except that it uses 92.0 wt% In2O3 powder, 3.9 wt% ZnO powder, and 4.1 wt% SnO2 powder.

[0040] Based on a total weight of 100 wt% of the sintered body in Specific Example 4(E4), the total amount of In, Zn, and Sn content in Specific Example 4(E4) of the present invention is 100 at%, with an In content of 89.82 at%, a Zn content of 6.50 at%, a Sn content of 3.69 at%, and an In-to-Sn ratio (In / Sn) of 24.34, and a Zn-to-In ratio (Zn / In) of 0.07.

[0041] The specific composition and related analytical data of Specific Example 4(E4) of the present invention are shown in Table 1 below.

[0042] <Comparative example 1 (CE1)> The method for producing the indium zinc tin sputtering target material of Comparative Example 1 (CE1) of the present invention is similar to the method for producing the material of Specific Example 1 (E1), except that it uses 95.0 wt% In2O3 powder, 0.9 wt% ZnO powder, and 4.1 wt% SnO2 powder.

[0043] Based on a total weight of 100 wt% of the sintered body of Comparative Example 1 (CE1), the In content of Comparative Example 1 (CE1) of the present invention is 94.70 at%, the Zn content is 1.53 at%, the Sn content is 3.76 at%, the ratio of In content to Sn content (In / Sn) is 25.19, and the ratio of Zn content to In content (Zn / In) is 0.02.

[0044] The specific composition and related analytical data of Comparative Example 1 (CE1) of the present invention are shown in Table 1 below.

[0045] <Comparative Example 2 (CE2)> The method for producing the indium zinc tin sputtering target material of Comparative Example 2 (CE2) of the present invention is similar to the method for producing the material of Specific Example 1 (E1), except that it uses 90.0 wt% In2O3 powder, 5.0 t% ZnO powder, and 5.0 wt% SnO2 powder.

[0046] Based on a total weight of 100 wt% of the sintered body of Comparative Example 2 (CE2), the In content of Comparative Example 2 (CE2) of the present invention is 87.27 at%, the Zn content is 8.27 at%, the Sn content is 4.46 at%, the ratio of In content to Sn content (In / Sn) is 19.57, and the ratio of Zn content to In content (Zn / In) is 0.09.

[0047] The specific composition and related analytical data of Comparative Example 2 (CE2) of the present invention are shown in Table 1 below.

[0048] <Comparative Example 3 (CE3)> Comparative Example 3 (CE3) is an indium tin oxide (ITO) sputtering target material synthesized by the applicant. Specifically, Comparative Example 3 (CE3) is a sintered body formed by sintering 90 wt% In2O3 powder and 10 wt% SnO2 powder.

[0049] <Method for manufacturing indium zinc tin conductive film> Each specific example (E1, E2, E3, E4) and each comparative example (CE1, CE2, CE3) of the indium zinc tin oxide conductive film of the present invention was obtained by DC sputtering using a DC cluster sputtering system, using the indium zinc tin oxide sputtering target material obtained by the respective manufacturing methods of the above specific examples E1, E2, E3, E4 and comparative examples CE1, CE2, and the ITO sputtering target material of comparative example 3 (CE3), respectively. Specifically, the DC cluster sputtering system has a plurality of vacuum chambers, each vacuum chamber is equipped with a target mounting section, and the sputtering target material of each specific example (E1, E2, E3, E4) and each comparative example (CE1, CE2, CE3) is installed in the target mounting section.

[0050] When performing the DC sputtering method, each of a plurality of glass substrates having dimensions of 10 cm × 10 cm × 0.7 cm is installed on a substrate installation part in a corresponding vacuum chamber. A flexible substrate is attached to the glass substrate so that the distance from the corresponding sputtering target material is 7 cm to 8 cm. The vacuum chamber is maintained to have a working pressure of 2 mTorr to 8 mTorr, and sputtering is performed on the sputtering target materials of each specific example and each comparative example with an output of 3 W / cm 2 to form conductive films of each specific example and each comparative example on the corresponding flexible substrates.

[0051] For each specific example (E1, E2, E3, E4) and each comparative example (CE1, CE2, CE3) of the indium zinc tin oxide conductive film of the present invention, samples with a thickness of 90 nm and samples with a thickness of the 130 nm were created.

[0052] The flexible substrate is made of a polymer such as polyvinyl alcohol (PVA), polyester (PET), or polyimide (PI). Since the constituent material of the flexible substrate is not a technical feature of the present invention, detailed description thereof is omitted.

[0053] <Sintered body of indium zinc tin oxide sputtering target material and analysis data of indium zinc tin oxide conductive film> When comparing the indium zinc tin oxide sputtering target materials of Specific Example 2 (E2), Specific Example 3 (E3), and Specific Example 4 (E4) of the present invention with the XRD data file of the cubic crystal phase of In2O3 (that is, the JCPDS card No. 06-0416), in the XRD diagrams of Specific Example 2 (E2), Specific Example 3 (E3), and Specific Example 4 (E4) (see FIGS. 1, 2, and 3), diffraction signal peaks corresponding to the In2O3 crystal phases such as the (211) plane, (222) plane, and (400) plane are shown at diffraction angles (2θ) of about 21.5 degrees, about 30.6 degrees, about 35.5 degrees, etc.

[0054] Furthermore, when comparing with the XRD data file for the hexagonal phase of Zn3In2O6 (i.e., JCPDS card number 20-1439), diffraction angles (2θ) of approximately 25.1 degrees, 31.5 degrees, and 34.2 degrees are observed, along with the (00012) plane, the (00015) plane, and

number

[0055] Based on the above, the sintered bodies of Specific Examples 2(E2), 3(E3), and 4(E4) are indeed composed of an In2O3 crystalline phase and a Zn3In2O6 crystalline phase.

[0056] On the other hand, the XRD diagram (see Figure 4) showing the crystal structure of the indium zinc tin oxide sputtering target material of Comparative Example 1 (CE1) shows only diffraction signal peaks belonging to the In2O3 crystal phase, and no diffraction signal peaks belonging to the Zn3In2O6 crystal phase are shown.

[0057] Comparing the XRD diagrams of Specific Examples 2 (E2), 3 (E3), and 4 (E4) with the XRD diagram of Comparative Example 1 (CE1), it is considered that the indium zinc tin oxide conductive films formed by sputtering the indium zinc tin oxide sputtering target materials of Specific Examples 2 (E2), 3 (E3), and 4 (E4) have higher flexibility than the indium zinc tin oxide conductive film formed by sputtering the indium zinc tin oxide sputtering target material of Comparative Example 1 (CE1). The evaluation of the flexibility of these indium zinc tin oxide conductive films will be explained in detail below.

[0058] To avoid redundancy in the specification due to excessive analytical data, the specific composition and related analytical data for each specific example and comparative example are summarized in Table 1 below, including only the ratio of In2O3 crystalline phase to Zn3In2O6 crystalline phase, the proportion occupied by the Zn3In2O6 crystalline phase, relative density, and resistivity. Further detailed data are omitted from the analysis.

[0059] The relative density of the sintered sputtering target material was determined by measuring the apparent density (Da) of each specific example and comparative example using the Archimedes method.

number

[0060] As shown in Table 1, the sintered bodies of all specific examples are formed from an In2O3 crystalline phase and a Zn3In2O6 crystalline phase. The amount of the Zn3In2O6 crystalline phase in the sintered body of each specific example decreases from 6.8% to 1.70% as the Zn content decreases. Therefore, it can be estimated that the flexibility of the conductive film formed by sputtering the sintered body of each specific example decreases as the Zn content decreases (details will be explained later). In addition, the relative density exceeded 99% in the sintered bodies of all specific examples.

[0061] Furthermore, as shown in Table 1, while the sintered body of Comparative Example 1 (CE1) contains Zn atoms, the content is insufficient (i.e., Zn / In is less than 0.05), resulting in a deficiency of the Zn3In2O6 crystalline phase. Therefore, it can be inferred that the flexibility of the conductive film formed by sputtering the sintered body of Comparative Example 1 (CE1) is not applicable to electronic equipment industries that require flexibility (details will be explained later).

[0062] Furthermore, in the sintered body of Comparative Example 2 (CE2), a Zn3In2O6 crystalline phase was formed by Zn atoms, but because the Sn content was too high (i.e., In / Sn was less than 20), the Sn atoms could not completely dissolve in the In2O3 crystalline phase, resulting in the formation of a Zn2SnO4 crystalline phase, which causes an increase in the volume resistivity of the sintered body. Consequently, the amount of Zn3In2O6 crystalline phase in the sintered body was only 1.2%.

[0063] The volume resistivity of the sintered bodies of each specific example and comparative example (CE1, CE2) of the present invention was measured using a four-probe resistivity meter (Napson, RT-70). According to the measurement results shown in Table 1, the volume resistivity of the sintered body of Comparative Example 2 (CE2) was 22 × 10⁻⁶. -4 It increased to Ω-cm. The Zn3In2O6 crystalline phase leads to an increase in volume resistivity, and in the sintered bodies of each specific example of the present invention, the volume resistivity is 18 × 10⁻⁶. -4 It is maintained at less than Ω-cm.

[0064] The resistivity of the indium zinc tin oxide conductive films of each specific example and comparative example (CE1, CE2) of the present invention was measured using a four-probe resistivity meter (CDE Corporation, ResMap). According to the measurement results shown in Table 1, when the thickness of each specific example of the present invention is 130 nm, the resistivity is 9.5 × 10⁻⁶. -4 It is maintained at less than Ω-cm. However, the film resistivity of Comparative Example 2 (CE2) is 9.8 × 10⁻⁶. -4 It had increased to Ω-cm.

[0065] Furthermore, for measuring the flexibility of the indium zinc tin oxide conductive films of each specific example and comparative example of the present invention, there are two types of flexibility measurements: static bending and dynamic bending.

[0066] Static bending involves maintaining a bend of 120 nm thick indium zinc tin oxide conductive film with a radius of curvature less than 2 mm for 240 hours, and then observing the cracks in the indium zinc tin oxide conductive film using an optical microscope (OM). The static bending data was divided into two types: pre-annealing and post-annealing. Annealing involves performing an annealing treatment on the indium zinc tin oxide conductive film at a temperature of 150°C or higher.

[0067] Dynamic bending involves repeatedly bending the conductive film, which has thicknesses of 90 nm and 130 nm, with a radius of curvature less than 3 mm 200,000 times. Then, the change in electrical resistivity (ΔR) before and after dynamic bending is measured using a four-probe resistivity meter (CDE Corporation, ResMap). The change in electrical resistivity (ΔR) is:

number

[0068] According to the measurement results shown in Table 1, no cracks were observed when static bending was applied to the conductive films of each specific example before annealing. On the other hand, when static bending was applied to the conductive film of Comparative Example 1 (CE1) before annealing, clear cracks were observed. In other words, the sintered body of Comparative Example 1 (CE1) lacked the Zn3In2O6 crystal phase, demonstrating that the flexibility of the conductive film formed by sputtering the sintered body of Comparative Example 1 (CE1) was inferior, and thus the conductive film of Comparative Example 1 (CE1) is unlikely to be suitable for application in electronic equipment industries that require flexibility.

[0069] Furthermore, according to the measurement results shown in Table 1, when static bending was performed on the conductive films of each specific example after annealing, no cracks occurred in specific examples 1 (E1), 2 (E2), and 3 (E3) (see Figure 5, for example, the OM image of the conductive film of specific example 3 (E3) after static bending following annealing), while slight cracks occurred in specific example 4 (E4). The reason for the slight cracks in specific example 4 (E4) is that the Zn3In2O6 crystalline phase was relatively small at 1.70% in the sintered body of specific example 4 (E4). Also, slight cracks occurred in the conductive film of comparative example 2 (CE2) after static bending following annealing. In other words, it was demonstrated that the flexibility of the conductive film decreases with decreasing Zn content.

[0070] Furthermore, as shown in Figure 6, when the conductive film of Comparative Example 3 (CE3) was subjected to static bending after annealing, cracks clearly appeared, which are undesirable in the electronics industry where flexibility is required. This is because the sintered body of Comparative Example 3 (CE3) does not contain Zn, and therefore lacks the Zn3In2O6 crystalline phase.

[0071] Referring to Figure 7 and Table 1, the change in electrical resistivity (ΔR) from the dynamic bending measurement results of the conductive films of each specific example and each comparative example 1 (CE1) and comparative example 2 (CE2) of the present invention is analyzed. When the thickness of each specific example of the present invention was 90 nm, the change in electrical resistivity after dynamic bending was a maximum of 2.5%, and when the thickness was 130 nm, the change in electrical resistivity after dynamic bending was a maximum of 9.5%. Furthermore, when the thickness of comparative example 2 (CE2) was 130 nm and 90 nm, the changes in electrical resistivity after dynamic bending were 15.6% and 13.7%, respectively, thus demonstrating the inferences regarding the flexibility of the conductive films of each specific example and comparative example described above.

[0072] [Table 1]

[0073] Referring to Figure 8 and Table 2, Specific Examples 2(E2), 3(E3), and 4(E4) of the present invention have an average transmittance of approximately 90% for electromagnetic waves including light in the visible light wavelength range (400nm to 800nm) and the wavelength range used in the field of solar power generation (400nm to 1000nm), and an average transmittance of approximately 80% for light in the harmful blue light wavelength range (415nm to 455nm). In other words, the blocking rate for harmful blue light is approximately 20%.

[0074] Comparative Example 3 (CE3) has an average transmittance of approximately 90% for electromagnetic waves, including light in the visible light wavelength range (400nm to 800nm) and the wavelength range used in the solar power generation industry (400nm to 1000nm), and an average transmittance of 87.5% for light in the harmful blue light wavelength range (415nm to 455nm). In other words, the blocking rate for harmful blue light is only about 12.5%.

[0075] Therefore, comparing Specific Examples 2 (E2), 3 (E3), and 4 (E4) with Comparative Example 3 (CE3), the indium zinc tin oxide conductive films of each specific example (E2, E3, E4) of the present invention can reduce damage caused by blue light that is harmful to the human body.

[0076] [Table 2]

[0077] According to the detailed explanation of the analytical data for each of the above specific examples and comparative examples, by including a sufficient amount of Zn in the sintered body of the indium zinc tin sputtering target material of each specific example of the present invention (the ratio of Zn content to In content exceeds 0.05, Zn / In > 0.05), the sintered body can have a Zn3In2O6 crystalline phase that increases the toughness of the conductive film. Furthermore, by limiting the Sn content (the ratio of In content to Sn content exceeds 20, In / Sn > 20), the Sn atoms can be completely dissolved in the In2O3 crystalline phase, thus preventing the formation of an unwanted third phase (Zn2SnO4 crystalline phase) in the sintered body. Therefore, in the sintered body of each specific example, the amount of Zn3In2O6 crystalline phase is 1.7% to 6.8%, and the volume resistivity is 18 × 10⁻⁶. -4 It is smaller than Ω-cm.

[0078] Furthermore, since each specific example contains a sufficient amount of Zn in its sintered body, the conductive film obtained by sputtering the sputtering target material of each specific example has a change in electrical resistivity (ΔR) of 2.5 × 10⁻¹⁰ when dynamic bending is applied and the thickness is 90 nm. -4 The change in electrical resistivity (ΔR) when the material is Ω-cm and has a thickness of 130 nm is 9.5 × 10⁻⁶. -4 It has a density of Ω-cm. Therefore, it is suitable for use as a TCO film in the electronics industry where flexibility is required.

[0079] Furthermore, in the conductive films of specific examples (E2, E3, E4), the average transmittance of harmful blue light is around 80%, meaning that the blocking rate of harmful blue light is at least 19.6% and at most 24.8%. Therefore, when used in flexible displays, it can reduce the damage caused by blue light that is harmful to the human body.

[0080] Therefore, the indium zinc tin sputtering target material of the present invention and the indium zinc tin conductive film formed thereby can be used in electronics industries that require flexibility.

[0081] All patents and references cited herein, as well as the references listed therein, are incorporated herein by reference in their entirety. In the event of any conflict, including definitions, this description shall prevail.

[0082] While preferred embodiments and variations of the present invention have been described above, the present invention is not limited thereto, and all modifications and equivalent formations are to be included as various configurations within the spirit and scope of the broadest interpretation. [Industrial applicability]

[0083] The indium zinc tin sputtering target material and the indium zinc tin conductive film formed thereby according to the present invention are suitable for application in electronic equipment industries that require flexibility.

Claims

1. A sintered body consisting only of In, Zn, Sn, and O, The sintered body is In ２ O ３ Crystalline phase and Zn ３ In ２ O ６ Composed only of the crystalline phase, When the total amount of In, Zn, and Sn is 100 at%, the In content is within the range of 77 at% to 90 at%, and the ratio of Zn content to In content is greater than 0.

05. The Zn content is within the range of 6.5 at% to 19 at% of the total amount of In, Zn, and Sn (100 at%). The ratio of In content to Sn content exceeds 20. In the sintered body, Zn ３ In ２ O ６ An indium zinc tin oxide sputtering target material characterized in that the amount of crystalline phase is within the range of 1.5% to 7%.

2. The relative density of the sintered body exceeds 99%, The volume resistivity of the sintered body is less than 18×10 －４ Ω-cm, and the indium zinc tin oxide sputtering target material according to claim 1 is characterized by this.

3. In the sintered body, Zn ３ In ２ O ６ The amount of crystalline phase is in the range of 2% to 5%. The volume resistivity of the sintered body is 14 × 10 －４ The indium zinc tin oxide sputtering target material according to claim 1, characterized in that it is smaller than Ω-cm.

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