Indium titanium zinc oxide sputtering target, thin film thereof, and method for manufacturing the same

Abstract

An indium titanium zinc oxide sputtering target includes a sintered body of In, Ti, Zn, and O. The sintered body includes an In2O3 crystal phase and an In2TiO5 crystal phase. The atomic content of In is 63 at.% or more, the atomic content of Ti is 10 at.% or more and 30 at.% or less, and the atomic content of Zn is 2 at.% or more, based on the total atomic content of In, Ti, and Zn being 100 at.%. A film sputtered from the sputtering target and a method of manufacturing the sputtering target are also provided. The sputtering target and the film sputtered therefrom have a high optical refractive index, which meets the requirements of the optical and electronic industries.

Description

TECHNICAL FIELD

[0001] The present application relates to a sputtering target material, in particular to an indium titanium zinc oxide sputtering target material, a thin film thereof and a method for manufacturing the same. BACKGROUND

[0002] Indium tin oxide (ITO) is a common transparent conductive oxide (TCO). Commercially available ITO thin films have low resistivity (1.89 x 10 -4 Ω-cm) and high transmittance (about 93.9% at wavelengths longer than 550 nm based on a film thickness of 130 nm), and are thus widely used in the optoelectronic device industry, such as displays, solar cells, light emitting diodes (LEDs), organic light emitting diodes (OLEDs), and the like, as transparent electrodes for various electronic devices. The ITO thin films are mostly formed by sputtering.

[0003] ITO thin films are also one of the common conductive materials in the optical field and the touch panel industry. In the case of a sputtering system integrated with an ITO sputtering target material, the sputtering rate of the ITO sputtering target material can be as high as 1.2 nm / sec when the output power density of the sputtering system is set to 1 W / cm 2 Although the sputtering rate of the ITO sputtering target material is fast, the optical refractive index of the ITO thin film is only 2.02 at a wavelength of 550 nm, which is difficult to meet the requirements of high optical refractive index optical films. High optical refractive index thin film materials commonly used in the optoelectronic field, such as niobium pentoxide (Nb2O5), have an optical refractive index as high as 2.3 at a wavelength of 550 nm. However, the sputtering rate of the Nb2O5 sputtering target material is less than 0.2 nm / sec when the output power density of the sputtering system is set to 1 W / cm 2 , which is difficult to meet the requirements of mass production speed.

[0004] For example, Taiwan Patent No. I608111 (hereinafter referred to as Prior Art 1) discloses an oxide sputtering target, a conductive oxide film with high optical refractive index, and a method for manufacturing an oxide sputtering target. According to the content of Prior Art 1, the oxide sputtering target is applied to an optoelectronic device, has a low bulk resistivity, can be used for direct current (DC) sputtering, and can form a transparent and high optical refractive index film. Prior Art 1 also discloses that the sintered body of the oxide sputtering target is composed of indium oxide (In2O3) powder, titanium oxide (TiO2) powder, and a large amount of zinc oxide (ZnO) powder mixed and sintered by hot pressing. The film formed by sputtering the oxide sputtering target has an optical refractive index of 2.05 or more at a wavelength of 550 nm, and has a sufficiently low target bulk resistivity to increase the film formation speed and improve the sputtering efficiency. However, the manufacturing method of the oxide sputtering target uses a high proportion of zinc oxide powder. Whether the oxide sputtering target composed of a high content of ZnO powder sintered by hot pressing or the film sputtered by the aforementioned oxide sputtering target, both have poor weather resistance. Therefore, when applied to the optoelectronic device industry, the service life of the optoelectronic device is easily affected.

[0005] As described above, improving the composition and structure of the sputtering target used in the technical industry requiring high optical refractive index so that the film formed by sputtering the target can not only meet the demand of the industry for optical refractive index, but also meet the requirement of the industry for sputtering rate and time cost, is a problem to be solved by those skilled in the art. SUMMARY

[0006] The first object of the present application is to provide an indium titanium zinc oxide sputtering target that can meet the demand of the industry for optical refractive index and meet the requirement of the industry for sputtering rate and time cost.

[0007] The indium titanium zinc oxide sputtering target of the present application comprises a sintered body containing In, Ti, Zn, and O. The sintered body contains In2O3 crystal phase and In2TiO5 crystal phase; wherein, based on the total atomic content of In, Ti, and Zn being 100 at.%, the atomic content of In is 63 at.% or more, the atomic content of Ti is 10 at.% or more and 30 at.% or less, and the atomic content of Zn is 2 at.% or more.

[0008] The indium titanium zinc oxide sputtering target of the present application has an atomic content of In between 66 at.% and 83 at.%, an atomic content of Ti between 13 at.% and 26 at.%, and an atomic content of Zn between 2.5 at.% and 7.5 at.%.

[0009] The In2TiO5 crystal phase in any one of the plurality of scanning electron microscope images measured from the sintered body has an area ratio of 25% to 70% with respect to the entire area of the corresponding scanning electron microscope image.

[0010] The In2O3 crystal phase in the In2TiZnO5 sputtering target of the present application has Ti, Zn, or a combination of Ti and Zn dissolved therein, and (Ti+Zn) / In is 5% to 15% in terms of atomic percentage of In, Ti, and Zn.

[0011] The In2TiZnO5 sputtering target of the present application further contains a Zn3In2O6 crystal phase.

[0012] The In2TiZnO5 sputtering target of the present application has a sputtering rate of 0.2 nm / sec or more when the In2TiZnO5 sputtering target is incorporated into a sputtering system under sputtering conditions in which the output power density of the sputtering system is 1 W / cm 2

[0013] In addition, a second object of the present application is to provide an In2TiZnO5 thin film.

[0014] The In2TiZnO5 thin film of the present application, which is sputtered using the In2TiZnO5 sputtering target as described above, has an optical refractive index of 2.1 or more under the condition of a light wavelength of 550 nm.

[0015] In addition, a third object of the present application is to provide a method for producing the aforementioned In2TiZnO5 sputtering target.

[0016] The method for producing the In2TiZnO5 sputtering target of the present application sequentially includes the following steps: step (a), step (b), step (c), step (d), step (e), step (f), and step (g).

[0017] The step (a) is to apply a first wet ball milling process to a first composition in which In2O3 powder and TiO2 powder are mixed, thereby becoming a first mixed slurry containing refined In2O3 powder and refined TiO2 powder.

[0018] The step (b) is to apply a first granulating process to the first mixed slurry, thereby becoming a first granulated powder.

[0019] The step (c) is to apply a calcining process to the first granulated powder, thereby becoming a powder containing an In2TiO5 crystal phase.

[0020] ​The step (d) is to apply a second wet ball milling process to a second composition mixed with the ZnO powder and the powder containing the In2TiO5 crystalline phase in the step (c), so as to become a second mixed slurry containing the refined ZnO powder and the refined powder containing the In2TiO5 crystalline phase.

[0021] The step (e) is to apply a second granulation process to the second mixed slurry, so as to become a second granulated powder.

[0022] The step (f) is to apply a mold forming process to the second granulated powder, so as to make the second granulated powder into a green body.

[0023] The step (g) is to apply a sintering process to the green body, so as to make the green body into a sintered body containing the In2O3 crystalline phase and the In2TiO5 crystalline phase.

[0024] In the present application, the content of the In2O3 powder is 75 wt.% or more, the content of the TiO2 powder is 5 wt.% or more and 20 wt.% or less, and the content of the ZnO powder is 1 wt.% or more, based on the total weight of the In2O3 powder, the TiO2 powder, and the ZnO powder in the step (a) being 100 wt.%.

[0025] In the method for manufacturing the indium titanium zinc oxide sputtering target of the present application, the temperature used when the calcination process is performed in the step (c) is at least greater than 1250°C, and the time performed is at least more than 3 hours.

[0026] In the method for manufacturing the indium titanium zinc oxide sputtering target of the present application, the second composition in the step (d) is further mixed with a binder, and the binder is mixed into the second composition after the second wet ball milling process is performed for at least more than 3 hours, and the second wet ball milling process is continuously performed for at least more than 1 hour.

[0027] The present application has the beneficial effect that the refined In2O3 powder and the TiO2 powder are granulated and calcined first, so that the powder obtained by calcination contains the In2TiO5 crystalline phase, and then the ZnO powder is mixed to sequentially perform the processes of wet ball milling, granulation, mold forming, and sintering, so that the sputtering target containing the sintered body of the In2O3 crystalline phase and the In2TiO5 crystalline phase is obtained after sintering, thereby the light refractive index of the indium titanium zinc oxide thin film sputtered from the sputtering target can be improved to meet the requirements of the related industry on the light refractive index of the thin film. BRIEF DESCRIPTION OF DRAWINGS

[0028] Other features and effects of the present application will be clearly presented in the embodiments with reference to the accompanying drawings.

[0029] Figure 1 is a flow chart illustrating an embodiment of a method for manufacturing an indium titanium zinc oxide sputtering target according to the present application;

[0030] Figure 2 is an X-ray diffraction (XRD) pattern illustrating the crystal structure of a specific example 2 (E2) of an indium titanium zinc oxide sputtering target according to the present application;

[0031] Figure 3 is an XRD pattern illustrating the crystal structure of a specific example 4 (E4) of an indium titanium zinc oxide sputtering target according to the present application;

[0032] Figure 4 is an XRD pattern illustrating the crystal structure of a specific example 5 (E5) of an indium titanium zinc oxide sputtering target according to the present application;

[0033] Figure 5 is an XRD pattern illustrating the crystal structure of a comparative example 1 (CE1) of an indium titanium zinc oxide sputtering target according to the present application;

[0034] Figure 6 is a scanning electron microscope backscattered electron (SEM-BSE) image illustrating the distribution of an In2O3 crystalline phase and an In2TiO5 crystalline phase of a specific example 1 (E1) of an indium titanium zinc oxide sputtering target according to the present application;

[0035] Figure 7 is a SEM-BSE image illustrating the distribution of an In2O3 crystalline phase and an In2TiO5 crystalline phase of the specific example 2 (E2) of an indium titanium zinc oxide sputtering target according to the present application;

[0036] Figure 8 is a SEM-BSE image illustrating the distribution of an In2O3 crystalline phase and an In2TiO5 crystalline phase of a specific example 3 (E3) of an indium titanium zinc oxide sputtering target according to the present application;

[0037] Figure 9 is a SEM-BSE image illustrating the distribution of an In2O3 crystalline phase, an In2TiO5 crystalline phase and a Zn3In2O6 crystalline phase of the specific example 4 (E4) of an indium titanium zinc oxide sputtering target according to the present application;

[0038] Figure 10is a SEM-BSE image showing the distribution of an In2O3 crystal phase and an In2TiO5 crystal phase of the inventive indium titanium zinc oxide sputtering target of Example 5 (E5).

[0039] Figure 11 is a SEM-BSE image showing the distribution of an In2O3 crystal phase and a Zn3In2O6 crystal phase of the comparative indium titanium zinc oxide sputtering target of Comparative Example 1 (CE1). DETAILED DESCRIPTION

[0040] An embodiment of the inventive indium titanium zinc oxide sputtering target is a sintered body composed of In, Ti, Zn and O. The sintered body contains an In2O3 crystal phase and an In2TiO5 crystal phase; wherein, based on the total atomic content of In, Ti and Zn being 100 at.%, the atomic content of In is 63 at.% or more, the atomic content of Ti is 10 at.% or more and 30 at.% or less, and the atomic content of Zn is 2 at.% or more.

[0041] According to the long-term research and development experience of the applicant in the process of TCO sputtering targets, when the sintered body of the inventive sputtering target of this embodiment contains insufficient In2TiO5 crystal phase, it will result in insufficient optical refractive index of the indium titanium zinc oxide film obtained by sputtering. When the sintered body contains excessive In2TiO5 crystal phase, it will adversely affect the sputtering rate of the sputtering target. Therefore, preferably, the atomic content of In is between 66 at.% and 83 at.%, the atomic content of Ti is between 13 at.% and 26 at.%, and the atomic content of Zn is between 2.5 at.% and 7.5 at.%.

[0042] As described in the preceding paragraph, under the premise of increasing the optical refractive index of the indium titanium zinc oxide film obtained by sputtering the inventive sputtering target of this embodiment, the sputtering rate of the inventive sputtering target of this embodiment is not affected. More preferably, in any one of the SEM images obtained from the sintered body, the proportion of the area of the In2TiO5 crystal phase to the overall area of the corresponding SEM image is between 25% and 70%; still more preferably, the sintered body also contains a Zn3In2O6 crystal phase.

[0043] It should be further noted here that when the In2O3 crystal phase of the sintered body of this embodiment of the invention has Ti or Zn solid-solved therein, it is beneficial to improve the optical refractive index of the indium titanium zinc oxide film obtained by sputtering the sputtering target of this embodiment. Therefore, preferably, the In2O3 crystal phase has Ti, Zn, or a combination of Ti and Zn solid-solved therein, and in terms of the atomic percentage of In, Ti and Zn, the (Ti+Zn) / In of the In2O3 crystal phase is between 5% and 15%.

[0044] Preferably, when the indium titanium zinc oxide sputtering target of this embodiment of the present application is incorporated into a sputtering system, the indium titanium zinc oxide sputtering target has a sputtering rate of equal to or greater than 0.2 nm / sec under sputtering conditions in which the output power density of the sputtering system is 1 W / cm 2 Preferably, when the indium titanium zinc oxide sputtering target of this embodiment of the present application is incorporated into a sputtering system, the indium titanium zinc oxide sputtering target has a sputtering rate of equal to or greater than 0.2 nm / sec under sputtering conditions in which the output power density of the sputtering system is 1 W / cm

[0045] In addition, an embodiment of the indium titanium zinc oxide thin film of the present application, which is produced by sputtering using the indium titanium zinc oxide sputtering target of this embodiment, has a light refractive index of equal to or greater than 2.1 under conditions in which the wavelength of light is 550 nm.

[0046] Referring to Figure 1 , the method of producing the indium titanium zinc oxide sputtering target of this embodiment of the present application sequentially includes the following steps: step (a), step (b), step (c), step (d), step (e), step (f), and step (g).

[0047] The step (a) is a step in which a first composition, which is a mixture of an In2O3 powder and a TiO2 powder, is subjected to a first wet ball milling process S21, thereby becoming a first mixed slurry containing a refined In2O3 powder and a refined TiO2 powder.

[0048] The step (b) is a step in which the first mixed slurry is subjected to a first granulation process S22, thereby becoming a first granulated powder.

[0049] The step (c) is a step in which the first granulated powder is subjected to a calcination process S23, thereby becoming a powder containing an In2TiO5 crystal phase.

[0050] The step (d) is a step in which a second composition, which is a mixture of a ZnO powder and the powder containing the In2TiO5 crystal phase of step (c), is subjected to a second wet ball milling process S24, thereby becoming a second mixed slurry containing a refined ZnO powder and a refined powder containing the In2TiO5 crystal phase.

[0051] The step (e) is a step in which the second mixed slurry is subjected to a second granulation process S25, thereby becoming a second granulated powder.

[0052] The step (f) is a step in which the second granulated powder is subjected to a mold forming process S26, thereby causing the second granulated powder to become a green body.

[0053] The step (g) is a step in which the green body is subjected to a sintering process S27, thereby causing the green body to become the sintered body containing the In2O3 crystal phase and the In2TiO5 crystal phase of this embodiment of the present application.

[0054] In the present application, the In2O3 powder content is 75 wt.% or more, the TiO2 powder content is 5 wt.% or more and 20 wt.% or less, and the ZnO powder content is 1 wt.% or more, based on a total weight of 100 wt.% of the In2O3 powder in the step (a), the TiO2 powder, and the ZnO powder in the step (d). Preferably, the In2O3 powder content is between 78 wt.% and 90 wt.%, the TiO2 powder content is between 8 wt.% and 17 wt.%, and the ZnO powder content is between 1 wt.% and 5 wt.%.

[0055] In order to have a sufficient amount of In2TiO5 crystalline phase in the powder after the step (c) is performed, preferably, in the step (c), the temperature used when the calcination procedure S23 is performed is at least greater than 1250°C, and the time performed is at least more than 3 hours.

[0056] Preferably, in the step (d), the second composition is further mixed with a binder, and the binder is mixed into the second composition after the second wet ball milling procedure S24 is performed for at least more than 3 hours, and the second wet ball milling procedure S24 is continued for at least more than 1 hour.

[0057] <Method of manufacturing the target material>

[0058] <Example 1 (E1)>

[0059] The method of manufacturing the example 1 (E1) of the indium titanium zinc oxide sputtering target material of the present application is described in detail as follows.

[0060] First, In2O3 powder (890 g) and TiO2 powder (83 g) with a purity of greater than 3N, and a certain amount of zirconium oxide (ZrO2) balls used for the first wet ball milling procedure S21 with the aforementioned powders are mixed in a ball mill (not shown in the figure), and a dispersant and pure water are continuously mixed in the ball mill during the ball milling process to uniformly disperse the powders for grinding by the zirconium oxide balls, thereby forming a first mixed slurry containing In2O3 powder and TiO2 powder with an average particle size of less than 1 μm.

[0061] Next, the first mixed slurry is subjected to the first granulation procedure S22 by a spray granulator (not shown in the figure) to dry the first mixed slurry to form a large amount of first granulated powder with a diameter of less than 100 μm.

[0062] The first granulated powder is then subjected to a calcination procedure S23 at 1300°C for 4 hours to make the first granulated powder into a powder containing In2TiO5 crystalline phase.

[0063] Subsequently, the second wet ball milling process S24 is performed by mixing the ZnO powder (27 g) having a purity of greater than 3N, the powder containing the In2TiO5 crystalline phase, a dispersant, pure water, and zirconia balls in the ball mill, and then mixing a binder in the ball mill after 3 hours to perform the second wet ball milling process S24 for 1 hour, thereby forming a second mixed slurry containing the ZnO powder having an average particle diameter of less than 1 μm and the powder containing the In2TiO5 crystalline phase.

[0064] Next, the second mixed slurry is subjected to the second granulation process S25 by the spray granulator to dry the second mixed slurry, thereby forming a large amount of the second granulated powder having a diameter of less than 100 μm.

[0065] Subsequently, the second granulated powder is filled into a mold (not shown) having a size of 20 cm x 15 cm x 0.6 cm, and the mold is sealed and subjected to cold isostatic press (CIP) to perform the mold forming process S26 in the mold, thereby forming a green body.

[0066] Finally, the sintering process S27 is performed by placing the green body in a sintering furnace (not shown) into which oxygen is introduced, and sintering the green body at 1380°C for 10 hours, thereby obtaining the sintered body of the specific example 1 (E1) of the present application. The In, Ti, and Zn contents of the specific example 1 (E1) of the present application are each 82.4 at.%, 13.3 at.%, and 4.3 at.%, based on 100 at.% of the In, Ti, and Zn atomic contents of the specific example 1 (E1) of the present application, which are converted from the total weight of the sintered body of the specific example 1 (E1) of the present application, which is 100 wt.%. The specific composition and related analysis data of the specific example 1 (E1) of the present application are summarized in Table 1 below.

[0067] <Specific Example 2 (E2)>

[0068] The method for manufacturing the specific example 2 (E2) of the indium titanium zinc oxide sputtering target of the present application is substantially the same as that of the specific example 1 (E1), except that the In2O3 powder, the TiO2 powder, and the ZnO powder are each 890 g, 93 g, and 17 g, and the In, Ti, and Zn contents of the specific example 2 (E2) of the present application are each 82.4 at.%, 14.9 at.%, and 2.7 at.%, based on 100 at.% of the In, Ti, and Zn atomic contents of the specific example 2 (E2) of the present application, which are converted from the total weight of the sintered body of the specific example 2 (E2) of the present application, which is 100 wt.% (see Table 1 below).

[0069] <Specific Example 3 (E3)>

[0070] The manufacturing method of the specific example 3 (E3) of the indium titanium zinc oxide sputtering target of the present application is substantially the same as that of the specific example 1 (El), except that the In2O3 powder, the TiO2 powder and the ZnO powder are 853 g, 130 g and 17 g, respectively; and in addition, the In, Ti and Zn contents are 77.0 at.%, 20.4 at.% and 2.6 at.%, respectively, based on the atomic contents of In, Ti and Zn of the specific example 3 (E3) of the present application being 100 at.% (see Table 1 below), converted from the total weight of the sintered body of the specific example 3 (E3) being 100 wt.%.

[0071] <Specific Example 4 (E4)>

[0072] The manufacturing method of the specific example 4 (E4) of the indium titanium zinc oxide sputtering target of the present application is substantially the same as that of the specific example 1 (El), except that the In2O3 powder, the TiO2 powder and the ZnO powder are 785 g, 166 g and 49 g, respectively; and in addition, the In, Ti and Zn contents are 67.8 at.%, 25.0 at.% and 7.2 at.%, respectively, based on the atomic contents of In, Ti and Zn of the specific example 4 (E4) of the present application being 100 at.% (see Table 1 below), converted from the total weight of the sintered body of the specific example 4 (E4) being 100 wt.%.

[0073] <Specific Example 5 (E5)>

[0074] The manufacturing method of the specific example 5 (E5) of the indium titanium zinc oxide sputtering target of the present application is substantially the same as that of the specific example 1 (El), except that the In2O3 powder, the TiO2 powder and the ZnO powder are 816 g, 166 g and 18 g, respectively; and in addition, the In, Ti and Zn contents are 71.9 at.%, 25.4 at.% and 2.7 at.%, respectively, based on the atomic contents of In, Ti and Zn of the specific example 5 (E5) of the present application being 100 at.% (see Table 1 below), converted from the total weight of the sintered body of the specific example 5 (E5) being 100 wt.%.

[0075] <Comparative Example 1 (CE1)>

[0076] The manufacturing method of the specific example 3 (E3) of the indium titanium zinc oxide sputtering target of the present application is substantially the same as that of the specific example 1 (El), except that the In2O3 powder, the TiO2 powder and the ZnO powder are 853 g, 130 g and 17 g, respectively; and in addition, the In, Ti and Zn contents are 77.0 at.%, 20.4 at.% and 2.6 at.%, respectively, based on the atomic contents of In, Ti and Zn of the specific example 3 (E3) of the present application being 100 at.% (see Table 1 below), converted from the total weight of the sintered body of the specific example 3 (E3) being 100 wt.%.

[0077] First, In2O3 powder (890 g) having a purity of greater than 3N, TiO2 powder (42 g), and ZnO powder (68 g) were mixed in a ball mill (not shown in the figure), and a certain amount of zirconia balls used for the first wet ball milling process S21 with the aforementioned powders were mixed in the ball mill during the ball milling process, and a dispersant and pure water were continuously mixed in the ball mill during the ball milling process to uniformly disperse the powders to be ground by the zirconia balls, thereby forming a mixed slurry of In2O3 powder, TiO2 powder, and ZnO powder having an average particle size of less than 1 μm of Comparative Example 1 (CE1).

[0078] Next, the mixed slurry of Comparative Example 1 (CE1) was subjected to the first granulation process S22 by the spray granulator (not shown in the figure) to dry the mixed slurry to form a large amount of granulated powder of Comparative Example 1 (CE1) having a diameter of less than 100 μm.

[0079] Then, the granulated powder of Comparative Example 1 (CE1) was filled into the mold (not shown in the figure) and sealed, and CIP was provided to the sealed mold to perform the mold forming process S26 in the mold, thereby forming a green body of Comparative Example 1 (CE1).

[0080] Finally, the sintering process S27 was performed, and the green body of Comparative Example 1 (CE1) was placed in the sintering furnace (not shown in the figure) into which oxygen was introduced to sinter the green body at 1380°C for 10 hours, thereby producing a sintered body of Comparative Example 1 (CE1) of the present application. The total weight of the sintered body of Comparative Example 1 (CE1) was 100 wt.%, and the atomic contents of In, Ti, and Zn of Comparative Example 1 (CE1) of the present application were 100 at.%, and the contents of In, Ti, and Zn were 82.5 at.%, 6.8 at.%, and 10.7 at.%, respectively (see Table 2 below).

[0081] <Comparative Example 2 (CE2)>

[0082] The method for producing Comparative Example 2 (CE2) of the indium titanium zinc oxide sputtering target of the present application was substantially the same as that of Specific Example 1 (E1), except that the amounts of In2O3 powder, TiO2 powder, and ZnO powder were 740 g, 225 g, and 35 g, respectively, and the total weight of the sintered body of Comparative Example 2 (CE2) was 100 wt.%, and the atomic contents of In, Ti, and Zn of Comparative Example 2 (CE2) of the present application were 100 at.%, and the contents of In, Ti, and Zn were 62.2 at.%, 32.8 at.%, and 5.0 at.%, respectively (see Table 2 below).

[0083] <Comparative Example 3 (CE3)>

[0084] The manufacturing method of Comparative Example 3 (CE3) of the present application is substantially the same as that of Specific Example 1 (E1), except that the In2O3 powder, TiO2 powder and ZnO powder are 920 g, 70 g and 10 g, respectively. In addition, the total weight of the sintered body of Comparative Example 3 (CE3) is converted to 100 wt.%, and the atomic contents of In, Ti and Zn are converted to 100 at.%, the contents of In, Ti and Zn are 86.9 at.%, 11.5 at.% and 1.6 at.%, respectively (see Table 2 below).

[0085] <Deposition rate of indium titanium zinc oxide thin film and sputtering target>

[0086] The sintered bodies of the specific examples (E1, E2, E3, E4 and E5) and the comparative examples (CE1, CE2 and CE3) of the present application were prepared by a direct current sputtering method using a DC cluster sputtering system. Specifically, the DC cluster sputtering system was equipped with multiple vacuum chambers, and a target source mechanism was arranged in each vacuum chamber. The sputtering targets of the specific examples (E1, E2, E3, E4 and E5) and the comparative examples (CE1, CE2 and CE3) were respectively assembled on the target source mechanisms in the corresponding vacuum chambers. During the implementation of the direct current sputtering method, multiple glass substrates with dimensions of 10 cm x 10 cm x 0.7 cm were respectively arranged on a substrate holder in each corresponding vacuum chamber, so that the distance between each glass substrate and the corresponding sputtering target was between 7 cm and 8 cm. The working pressure of each vacuum chamber was maintained between 2 mTorr and 8 mTorr, and the direct current sputtering was performed for 20 seconds. The sputtering targets deposited thin films of the specific examples and the comparative examples on the corresponding glass substrates at an output power density of 1 W / cm2. 2

[0087] <Analysis data of sputtering target and thin film>

[0088] <Analysis of crystalline phase composition of sputtering target (XRD)>

[0089] The crystal structure of the sintered bodies of the specific examples (E1 to E5) and the comparative examples (CE1 to CE3) was analyzed using a Rigaku Ultima IV device. Cu-Kα rays were generated under the conditions of an X-ray tube voltage of 45 kV and a current of 40 mA. The detection conditions were set as follows using the 2θ-θ reflection method: measurement range (2θ) was 10 to 90 degrees; step width was 0.03 degrees; and step time was 1 s / step. ​

[0090] The XRD data file of the cubic crystal phase of In2O3 of the indium titanium zinc oxide sputtering target of the embodiment 2 (E2), embodiment 4 (E4) and embodiment 5 (E5) of the present invention (i.e., JCPDS card No. 65-3170) is compared, and it can be seen that the XRD patterns of the embodiment 2 (E2), embodiment 4 (E4) and embodiment 5 (E5) (see Figure 2 、 Figure 3 and Figure 4 ) in which the diffraction signal peaks of (211), (400) and (440) planes belonging to the In2O3 crystalline phase are displayed at the positions of twice the diffraction angle of approximately 21.5 degrees, approximately 35.5 degrees and approximately 51.5 degrees, respectively. Moreover, the indium titanium zinc oxide sputtering targets of the specific example 2 (E2), the specific example 4 (E4) and the specific example 5 (E5) are compared with the XRD data file of the In2TiO5 orthorhombic crystal phase (i.e., JCPDS card No. 30-0640). In the XRD patterns of the specific example 2 (E2), the specific example 4 (E4) and the specific example 5 (E5) (see Figure 2 、 Figure 3 and Figure 4 ) in which the double diffraction angles are respectively approximately 30.6 degrees and 36.2 degrees, the corresponding diffraction signal peaks of (112) crystal plane and (006) crystal plane belonging to In2TiO5 crystal phase are displayed. In addition, by comparing the XRD data file of Zn3In2O6 hexagonal crystal phase (i.e., JCPDS card No. 20-1439), it can be seen that the sputtering target of Example 4 (E4) has the following XRD pattern (see Figure 3 ) in which the double diffraction angles are respectively near 25.1 degrees, near 31.5 degrees and near 34.2 degrees, and the corresponding (00012) crystal plane, (00015) crystal plane and The diffraction signal peaks of the crystal planes and the like belong to the Zn3In2O6 crystal phase, which confirms that the sintered body of the specific example 4 (E4) of the present invention contains not only the In2O3 crystal phase and the In2TiO5 crystal phase, but also the Zn3In2O6 crystal phase. In contrast, the XRD pattern of the indium titanium zinc oxide sputtering target of the comparative example 1 (CE1) (see Figure 5 ), it only shows the diffraction signal peaks belonging to the In2O3 crystal phase and the Zn3In2O6 crystal phase, but lacks the diffraction signal peak of the In2TiO5 crystal phase.

[0091] The XRD patterns shown by the examples (E2, E4 and E5) and the comparative example 1 (CE1) can preliminarily infer that the optical refractive index of the thin film deposited by the indium titanium zinc oxide sputtering target of the examples (E2, E4 and E5) should be relatively higher than that of the thin film deposited by the sputtering target of the comparative example 1 (CE1). The test results of the optical refractive index of the aforementioned indium titanium zinc oxide thin film will be described later.

[0092] It should be noted here that the applicant avoids excessive analysis data to make the specification too long. Therefore, the crystal structure analysis of the sputtering targets of the examples and the comparative examples is not listed one by one. The analysis results of the In2O3 crystal phase, the In2TiO5 crystal phase and the Zn3In2O6 crystal phase in the sintered body of the examples (E1, E2, E3, E4, E5) and the comparative examples (CE1, CE2, CE3) are summarized in Tables 1 and 2 below.

[0093] Table 1

[0094]

[0095] 1 The elements in the parentheses are the elements dissolved in the In2O3 crystal phase or the Zn3In2O6 crystal phase.

[0096] 2 The proportion of the In2TiO5 crystal phase in the entire area of the corresponding SEM image from any one of the SEM images of the sintered body.

[0097] 3 The (Zn+Ti) / In ratio dissolved in the In2O3 crystal phase in terms of the atomic percentage of In, Ti and Zn.

[0098] 4 The sputtering rate of each sputtering target of the leaf-type sputtering system at an output power density of 1 W / cm2. 2

[0099] 5 The optical refractive index of the thin film deposited by the sputtering target of each example and each comparative example at a light wavelength of 550 nm.

[0100] Table 2

[0101]

[0102] 1 The elements in the parentheses are the elements dissolved in the In2O3 crystal phase or the Zn3In2O6 crystal phase.

[0103] 2 ​The proportion of In2TiO5 crystalline phase in the entire area of each corresponding SEM image.

[0104] 3 The (Zn+Ti) / In ratio solid-solved in the In2O3 crystalline phase, in terms of atomic percentage of In, Ti, and Zn.

[0105] 4 The sputtering rate of each sputtering target of the leaf-type sputtering system at an output power density of 1 W / cm2. 2 The sputtering rate of each sputtering target of the leaf-type sputtering system at an output power density of 1 W / cm2.

[0106] 5 The optical refractive index of the thin film obtained by sputtering the sputtering target of each embodiment and each comparative example at a light wavelength of 550 nm.

[0107] As shown in Table 1, the sintered body of each embodiment of the present application contains In2O3 crystalline phase and In2TiO5 crystalline phase, and the sintered body of the embodiment 4 (E4) also contains Zn3In2O6 crystalline phase. In contrast, as shown in Table 2, the sintered body of the comparative example 1 (CE1) contains Ti atoms, but lacks In2TiO5 crystalline phase due to the lack of the calcination process after mixing In2O3 powder and TiO2 powder and the insufficient amount of Ti atoms, and the sintered body of the comparative example 2 (CE2) contains In2TiO5 crystalline phase due to the excessive amount of Ti atoms, but lacks In2O3 crystalline phase.

[0108] <Analysis of crystalline phase of sputtering target (SEM) and composition analysis (EDX)>

[0109] The microstructure of the sintered bodies of the specific examples (E1 to E5) and the comparative examples (CE1 to CE3) of the present application was analyzed using a SEM device of the Hitachi N-3400 model, and it was observed that each sintered body contained two to three phases according to the gray scale presented in the SEM image of the sintered body. In addition, the composition and proportion of each crystalline phase contained in the sintered body were analyzed from the SEM-BSE image of the sintered body using an energy dispersive x-ray spectroscopy (EDX) device of the Hitachi N-3400 model, so as to mark the location of different crystalline phases in the SEM-BSE image of each sintered body, and define the area proportion of the In2TiO5 crystalline phase and the (Zn+Ti) / In ratio in the In2O3 crystalline phase through the analysis results. It is worth mentioning that the proportion of the area of the In2TiO5 crystalline phase in the corresponding SEM whole area was defined by calculating the proportion range of each sintered body from five positions of each sintered body, each of which was photographed as an SEM image, through the ImageJ image analysis software.

[0110] According to Figure 6 As shown in Table 3, the light gray part (labeled A) and the dark gray part (labeled B) in the SEM-BSE image of the specific example 1 (E1) of the present application are the In2O3 crystalline phase and the In2TiO5 crystalline phase, respectively, and the EDX analysis results are shown in Table 3 below. It can be seen that Zn is solid-solved in the In2O3 crystalline phase of the sintered body of the specific example 1 (E1), and the proportion of the area of the In2TiO5 crystalline phase in the whole area of the SEM-BSE image is between 25 and 31% (summarized in Table 1 above) calculated by the ImageJ image analysis software.

[0111] Table 3

[0112] at.% In2O3(A) In2TiO5(B) OK 71.5 68.7 TiK 0.0 11.6 ZnL 3.5 0.0 InL 25.0 19.7 Total 100.0 100.0

[0113] According to Figure 7 As shown in Table 4, the light gray part (labeled A) and the dark gray part (labeled B) in the SEM-BSE image of the specific example 2 (E2) of the present application are the In2O3 crystalline phase and the In2TiO5 crystalline phase, respectively, and the EDX analysis results are shown in Table 4 below. It can be seen that Zn is also solid-solved in the In2O3 crystalline phase of the sintered body of the specific example 2 (E2), and the proportion of the area of the In2TiO5 crystalline phase in the whole area of the SEM-BSE image is between 32 and 38% (summarized in Table 1 above) calculated by the ImageJ image analysis software.

[0114] Table 4

[0115] at.% In2O3(A) In2TiO5(B) OK 70.1 72.1 TiK 0.0 10.2 ZnL 1.7 0.0 InL 28.2 17.7 Total 100.0 100.0

[0116] According to Figure 8 As shown in Table 5, the lighter gray level (indicated as A) and the darker gray level (indicated as B) in the SEM-BSE image of the sintered body of the present application of Example 3 (E3) are In2Ti05crystalline phase and In2O3crystalline phase, respectively, and the EDX analysis results are shown in Table 5 below. It can be known that, in the In2O3crystalline phase of the sintered body of Example 3 (E3), Ti is also solid-solved in addition to Zn, and the proportion of the area of In2Ti05crystalline phase in the whole area of SEM-BSE image is between 44 and 50% (summarized in Table 1 above) calculated by ImageJ image analysis software.

[0117] Table 5

[0118] at.% In2O3(A) In2TiO5(B) OK 71.7 71.6 TiK 1.0 9.3 ZnL 1.2 0.0 InL 26.1 19.1 Total 100.0 100.0

[0119] According to Figure 9 As shown in Table 6, the lighter gray level (indicated as A), the lightest gray level (indicated as B) and the darker gray level (indicated as C) in the SEM-BSE image of the sintered body of the present application of Example 4 (E4) are In2Ti05crystalline phase, In2O3crystalline phase and Zn3In2O6crystalline phase, respectively, and the EDX analysis results are shown in Table 6 below. It can be known that, in the In2O3crystalline phase of Example 4 (E4), Ti is also solid-solved in addition to Zn, and the proportion of the area of In2Ti05crystalline phase in the whole area of SEM-BSE image is between 48 and 52% (summarized in Table 1 above) calculated by ImageJ image analysis software.

[0120] Table 6

[0121] at.% In2TiO5(A) In2O3(B) Zn2In2O6(C) OK 73.3 66.1 61.7 TiK 9.1 2.0 5.1 ZnL 0.0 2.2 18.4 InL 17.6 29.7 14.8 Total 100.0 100.0 100.0

[0122] According to Figure 10 As shown in Table 7, the lighter gray level (indicated as B) and the darker gray level (indicated as A) in the SEM-BSE image of the sintered body of the present application of Example 5 (E5) are In2O3crystalline phase and In2Ti05crystalline phase, respectively, and the EDX analysis results are shown in Table 7 below. It can be known that, in the In2O3crystalline phase of the sintered body of Example 5 (E5), Zn is solid-solved, and the proportion of the area of In2Ti05crystalline phase in the whole area of SEM-BSE image is between 67 and 70% (summarized in Table 1 above) calculated by ImageJ image analysis software.

[0123] Table 7

[0124] at.% In2O3(B) In2TiO5(A) OK 70.0 72.2 TiK 0.0 9.5 ZnL 2.1 0.0 InL 27.9 18.3 Total 100.0 100.0

[0125] According to Figure 11 As shown in Table 8, the lighter gray area (labeled B) and the darker gray area (labeled A) in the SEM-BSE image of the comparative example 1 (CE1) of the present application are the In2O3 crystalline phase and the Zn3In2O6 crystalline phase, respectively, and the EDX analysis results thereof are shown in Table 8 below. As can be seen from Table 8, the In2O3 crystalline phase in the sintered body of the comparative example 1 (CE1) does not have Zn or Ti solid-solved therein, and the proportion of the In2TiO5 crystalline phase area to the total area of the SEM-BSE image is 0% (see Table 2 above) as calculated by the ImageJ image analysis software. Although the SEM-BSE images of the comparative example 2 (CE2) and the comparative example 3 (CE3) are omitted in the present application for the sake of brevity, the applicants have analyzed the compositions thereof. As can be seen from Table 2, the proportions of the In2TiO5 crystalline phase area to the total area of the respective SEM-BSE images are 72 to 80% and 21 to 28% for the comparative example 2 (CE2) and the comparative example 3 (CE3), respectively (summarized in Table 2 above) as calculated by the ImageJ image analysis software.

[0126] Table 8

[0127] at.% In2O3(A) Zn3In2O6(B) OK 72.5 61.2 TiK 0.0 2.5 ZnL 0.0 23.3 InL 27.5 13.0 Total 100.0 100.0

[0128] It should be noted here that, as for the Zn atoms and Ti atoms solid-solved in the In2O3 crystalline phase of the sintered bodies of the specific examples and the comparative examples of the present application, the applicants have added the atomic percentage of the Zn element and the atomic percentage of the Ti element solid-solved in the In2O3 crystalline phase, and then divided the sum by the atomic percentage of the In element to obtain the (Zn+Ti) / In ratio in the In2O3 crystalline phase, which is summarized in Table 1 and Table 2 above.

[0129] <Analysis of sputtering rate>

[0130] After the indium titanium zinc oxide films of the specific examples and the comparative examples were prepared by sputtering, the film thickness of each film was measured by a film thickness measuring instrument (Veeco, Dektak 150), and then the measured film thickness of each film was divided by the execution time (20 seconds) of the direct current sputtering to obtain the sputtering rate of the respective sputtering targets of the specific examples and the comparative examples under the output power density condition of 1 W / cm2of the leaf-type direct current sputtering system, which is summarized in Table 1 and Table 2 above. 2

[0131] <Analysis of optical refractive index of film>

[0132] ​The optical refractive index of the thin films of the inventive examples (E1 to E5) and the comparative examples (CE1 to CE3) was measured at a wavelength of 550 nm using a dielectric layer analyzer of the model J. A. Woolam, M2000-DI, available from n&k Technology Inc.

[0133] As shown in Table 1, the sintered bodies of the inventive examples (E1 to E5) all contain In2O3crystalline phase and In2TiO5crystalline phase, and the sintered body of the inventive example 4 (E4) further contains Zn3In2O6crystalline phase. The proportion of the area of the In2TiO5crystalline phase in the whole area of the SEM-BSE image is between 25% and 70%, and the proportion of (Zn+Ti) / In in the In2O3crystalline phase is between 6.0% and 14.1%. In addition, the sputtering rate of the sintered bodies of the inventive examples (E1 to E5) is between 0.23 nm / sec and 0.35 nm / sec, and the optical refractive index of the indium titanium zinc oxide thin film prepared by sputtering the sputtering target of the inventive examples (E1 to E5) is between 2.124 and 2.260.

[0134] As shown in Table 1, the sputtering rate of the sputtering target of the inventive examples (E1 to E5) gradually decreases as the proportion of the area of the In2TiO5crystalline phase in the whole area of the SEM-BSE image gradually increases, but the factor affecting the sputtering rate also includes the composition and number of the crystalline phases. It is worth mentioning that even though the sintered body of the inventive example 4 (E4) further contains Zn3In2O6crystalline phase, the sputtering rate thereof is still maintained at 0.23 nm / sec, and the thin film obtained by sputtering has an optical refractive index value as high as 2.260.

[0135] As shown in the analysis data of Table 2, the sputtering target of Comparative Example 1 (CE1) indeed lacks the In2Ti05 crystalline phase in the sintered body due to the lack of the calcination process after mixing the In203 powder and the Ti02 powder, and the insufficient Ti atomic content, and also fails to dissolve Zn or Ti in the In203 crystalline phase. Although the sputtering rate of the sputtering target of Comparative Example 1 (CE1) can reach 0.59 nm / sec due to the lack of the In2Ti05 crystalline phase in the sintered body, the optical refractive index of the thin film obtained by sputtering the sputtering target is only 1.988, which is difficult to meet the requirements of the industry on the optical refractive index of the thin film. In addition, although the sputtering target of Comparative Example 2 (CE2) contains a higher Ti content and can contain the In2Ti05 crystalline phase in the sintered body, the sintered body does not contain the In203 crystalline phase due to the insufficient In content. Even though the optical refractive index of the thin film of Comparative Example 2 (CE2) can be as high as 2.280, the composition of the crystalline phase of the sputtering target is complex and the In203 crystalline phase is not seen, resulting in a sputtering rate of only 0.16 nm / sec, which is very difficult to meet the requirements of the industry on the time cost. Furthermore, although the sputtering target of Comparative Example 3 (CE3) contains a sufficient amount of Ti atoms and can contain the In2Ti05 crystalline phase in the sintered body, the In2Ti05 crystalline phase in the sintered body has an area proportion of only 21% in the whole area of the SEM-BSE image, and the (Zn+Ti) / In ratio in the In203 crystalline phase is only 4.6%. Although the sputtering rate of the sputtering target of Comparative Example 3 (CE3) can reach 0.34 nm / sec, the optical refractive index of the thin film of Comparative Example 3 (CE3) decreases from 2.280 of Comparative Example 2 (CE2) to 2.090, which is also difficult to meet the requirements of the industry on the optical refractive index of the thin film.

[0136] In summary, the indium titanium zinc oxide sputtering target, the thin film thereof, and the method of manufacturing thereof of the present application can meet the requirements of the industry on the sputtering rate and the time cost, and can improve the optical refractive index of the indium titanium zinc oxide thin film obtained by sputtering the sputtering target to meet the requirements of the industry on the optical refractive index of the thin film, so as to achieve the purpose of the present application.

[0137] The above description is only for the embodiments of the present application, and cannot limit the scope of the implementation of the present application. Any simple equivalent changes and modifications made in accordance with the claims and the content of the specification of the present application are still within the scope of the present application.

Claims

1. An indium titanium zinc oxide sputtering target, characterized by: The sintered body contains an In2TiO5 crystalline phase. The sintered body contains an In2TiO5 crystalline phase. The atomic content of In is between 66 at.% and 83 at.%, the atomic content of Ti is between 13 at.% and 26 at.%, and the atomic content of Zn is between 2.5 at.% and 7.5 at.% based on the total atomic content of In, Ti, and Zn being 100 at.%. The In2TiO5 crystalline phase is solid-solution with Ti and Zn, or a combination of Ti and Zn, and the (Ti+Zn) / In of the In2TiO5 crystalline phase is between 5% and 15% based on the atomic percentage of In, Ti, and Zn.

2. The indium titanium zinc oxide sputtering target according to claim 1, characterized by: The proportion of the area of the In2TiO5 crystalline phase in any one of the scanning electron microscope images taken from the sintered body is between 25% and 70% of the total area of the corresponding scanning electron microscope image.

3. The indium titanium zinc oxide sputtering target according to claim 1, characterized by: The sintered body further contains a Zn3In2O6 crystalline phase.

4. The indium titanium zinc oxide sputtering target according to claim 1, characterized by: When the indium titanium zinc oxide sputtering target is incorporated into a sputtering system, the indium titanium zinc oxide sputtering target has a sputtering rate of 0.2 nm / sec or more under sputtering conditions in which the output power density of the sputtering system is 1 W / cm 2 2.

5. An indium titanium zinc oxide film, characterized by: The In2TiO5 thin film is sputtered using the In2TiO5 sputtering target of any one of claims 1 to 4, and the optical refractive index of the In2TiO5 thin film is greater than or equal to 2.1 at a light wavelength of 550 nm.

6. A method of manufacturing an indium titanium zinc oxide sputtering target, characterized by: The method comprises the following steps in sequence: Step (a) is to apply a first wet ball milling process to a first composition mixed with In2O3 powder and TiO2 powder, thereby becoming a first mixed slurry containing refined In2O3 powder and refined TiO2 powder; Step (b) is to apply a first granulation process to the first mixed slurry to become a first granulated powder; Step (c) is to apply a calcination process to the first granulated powder to become a powder containing an In2TiO5 crystalline phase; Step (d) is to apply a second wet ball milling process to a second composition mixed with ZnO powder and the powder containing an In2TiO5 crystalline phase in step (c), thereby becoming a second mixed slurry containing refined ZnO powder and refined powder containing an In2TiO5 crystalline phase; Step (e) is to apply a second granulation process to the second mixed slurry to become a second granulated powder; Step (f) is to apply a mold forming process to the second granulated powder to become a green body; and Step (g) is to apply a sintering process to the green body to become a sintered body containing an In2O3 crystalline phase and an In2TiO5 crystalline phase; The content of the In2O3 powder is 75 wt.% or more, the content of the TiO2 powder is 5 wt.% or more and 20 wt.% or less, and the content of the ZnO powder is 1 wt.% or more, based on the total weight of the In2O3 powder, the TiO2 powder in step (a), and the ZnO powder in step (d) being 100 wt.%.

7. The method of claim 6, wherein the method further comprises: In step (c), the temperature used when the calcination process is performed is at least greater than 1250°C, and the time performed is at least more than 3 hours. ​ 8. The method of claim 6, wherein the method further comprises: In this step (d), the second composition is also mixed with a binder, and the binder is mixed into the second composition after the second wet ball milling process is performed for at least over 3 hours, and the second wet ball milling process is continued for at least over 1 hour. ​

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