TWI461556B - Indium target with tetragonal structure - Google Patents

Description

Indium target with tetragonal crystal structure

The present invention relates to an indium target, and more particularly to an indium target having a tetragonal crystal structure of refined grains.

Indium target is one of the materials commonly used in the preparation of Copper Indium Gallium Diselenide (CIGS) thin film solar cells. The grain size of the indium target is closely related to the formation of the arc during the sputtering process of the target and the uniformity of the plasma, so that the uniformity of the formed sputtering film is affected, thereby affecting the conversion efficiency of the produced solar cell.

Japanese Patent Publication No. 2012-052193 discloses a grain refining technique for an indium target, which uses ultrasonic vibration to reduce the grain size so that the average grain size of the finally obtained indium target is not more than 10 mm. . However, the minimum average grain size disclosed in the specification of the invention patent is only a millimeter grade, and cannot achieve a finer micron grade, so that the indium target described in the prior patent document is produced during the film sputtering process. The amount of arc cannot be effectively reduced, so that a large amount of particles generated by the arc are deposited on the surface of the sputtered film, thereby affecting the quality of the film formed by sputtering.

In addition, another method commonly used to refine the grain size of indium targets is cold rolling, but the cold rolling method is only applicable to planar targets, and it is not possible to use cold targets for non-planar targets such as rotating targets. The method of calendering achieves the purpose of grain refinement, so that the heteromorphic target is more difficult to have a smaller crystal grain size, and the problem that the conversion quality of the CIGS thin film solar cell produced by the poor quality of the film is poor is reduced, thereby reducing the problem. Due to its industrial applicability, it is necessary to develop an indium target with refined grains.

In order to solve the problem that the average grain size of the indium target of the prior art is too large, the present invention provides a tetragonal crystal indium target having an average grain size of 10 micrometers (μm) to 500 μm. between.

According to the present invention, the indium target of the tetragonal structure means that the lattice structure of the indium target is a tetragonal arrangement.

According to the present invention, the purity of the indium target of the tetragonal crystal structure of the present invention is, for example but not limited to, greater than 99.95% (3N5).

In accordance with the present invention, the indium target of the tetragonal structure of the present invention refers to any form of indium target, such as, but not limited to, a planar target or a shaped target.

In accordance with the present invention, the average grain size of the present invention is, for example, but not limited to, the average of the grain sizes of the surface of the indium target having a tetragonal crystal structure of 1.0 x 1.3 square centimeters per unit area. The method for measuring the average grain size is, for example, but not limited to, enlarging the surface with an optical microscope at a magnification of 100 and acquiring an image, and drawing four tangent lines on the image, the four tangent lines are arranged in a m-shape, and the image analysis software is used. The grain size is measured, and the average grain size of the four tangent lines is calculated separately, and the total average of the average grain sizes of the four tangent lines is calculated.

Preferably, the indium target of the tetragonal structure has an average grain size of between 10 μm and 400 μm.

According to the present invention, the indium target of the tetragonal crystal structure of the present invention forms an indium solution by smelting, and then forms a tetragonal crystal indium target by a casting method, and the indium target of the tetragonal crystal structure is in a mold. Internally, a cooling medium is rapidly flowed through the mold relative to one side of the indium target of the tetragonal structure, preferably, An inlet end is disposed on a side of the side of the mold and an outlet end is formed at a distance from the inlet end, so that the cooling medium flows from the inlet end and flows out from the outlet end, thereby rapidly lowering the mold temperature, thereby achieving rapid cooling. The purpose of the tetragonal crystal indium target.

According to the present invention, the "rapid cooling" of the present invention causes a cooling medium to flow through a side of the mold relative to the indium target of the tetragonal structure at a specific rate, thereby transferring the indium target of the tetragonal structure. Thermal energy until the indium target of the tetragonal structure reaches the desired temperature. Anyone can adjust the rate of cooling as needed to allow the indium target of the tetragonal structure to be rapidly cooled. Preferably, the rapid cooling means that the temperature of the indium target of the tetragonal structure is lowered from 206 ° C to 50 ° C to 70 ° C within 5 minutes.

According to the present invention, the aforementioned cooling medium can be a non-hazardous and stable material, and a fluid substance that does not affect the overall target process. Preferably, the cooling medium includes, but is not limited to, water, oil or gas.

According to the present invention, the "indium target rapid cooling of the tetragonal structure" means that the square is transferred by a cooling medium flowing through the mold with respect to one side of the indium target of the tetragonal structure. The indium target thermal energy of the crystal structure causes the indium target of the tetragonal structure placed in the mold to be rapidly cooled from a direction close to the cooling medium, which can be applied to any form of indium target, such as but not limited to Planar targets or shaped targets.

Preferably, the ratio of the average grain size of the two ends of the indium target of the tetragonal structure is between 0.5 and 2.0.

According to the present invention, the two ends of the present invention are a front end and a rear end, the front section being adjacent to the aforementioned inlet end and the rear section being adjacent to the aforementioned outlet end.

According to the present invention, the ratio of the average grain size of the two ends of the present invention is, for example, the ratio of the front stage to the back stage or the ratio of the back stage to the front stage.

Preferably, the indium target of the tetragonal structure has an oxygen content of not more than 50 ppm.

Preferably, the indium target of the tetragonal structure has an iron content of not more than 20 ppm.

Preferably, the indium target of the tetragonal structure has a zinc content of not more than 20 ppm.

Preferably, the indium target of the tetragonal structure has a tin content of not more than 20 ppm.

Preferably, the surface of the indium target of the tetragonal structure comprises the following crystal faces: (101), (103), (200), (112) (110), (211), (202), and (002) .

Preferably, the indium target of the tetragonal structure is a planar target.

According to the present invention, the planar target of the present invention is, for example but not limited to, a circular target or a rectangular target.

Preferably, the indium target of the tetragonal structure is a heterogeneous target of a non-planar target.

According to the present invention, the shaped target of the present invention is, for example but not limited to, a rotating target or a stepped target.

Preferably, the indium target of the tetragonal structure is not subjected to the step of cold rolling, and the intensity ratio of each crystal face is 12.5% (the ratio of the intensity of each crystal face having no random orientation: 100%/8 peaks) The ratio of =12.5%/per peak) is between 0.5 and 2.0.

According to the present invention, when the indium target of the tetragonal crystal structure of the present invention is a planar target, the step of cold rolling can be further performed, whereby the indium target has a crystal. The preferred direction of the face.

Preferably, the indium target of the tetragonal crystal structure is a planar target and the ratio of the intensity ratio of one crystal plane to the ratio of the strength of each crystal plane of 12.5% (the ratio of each crystal plane in the preferred direction) is greater than 2.

According to the present invention, the quality of the indium target of the tetragonal crystal structure of the present invention is determined by the number of micro arcs generated during the sputtering process and the number of hard arcs.

According to the present invention, the instrument for testing the number of arcs of the present invention is an instrument of the type Pinnacle (manufactured by Advanced Energy), and the test method is in the sputtering process, and the voltage value of an arc is detected to be lower than 50 V, and the arc is detected. The sustain time is less than 40 milliseconds, and the arc is called a micro-arc; if an arc value of less than 50V is detected and the arc is maintained for more than 40 milliseconds, the arc is called a strong arc.

The indium target of the tetragonal crystal structure provided by the invention has a mean grain size of between 10 and 500 micrometers (μm), which is much smaller than the average grain size of the prior art indium target, so sputtering In the process, the number of arc generations can be greatly reduced, and the indium fine particles are greatly reduced on the surface of the sputtering film, thereby increasing the quality of the sputtering film, for example, greatly improving the uniformity of the film.

The ratio of the average grain size of the two ends of the indium target of the tetragonal crystal structure of the present invention is between 0.5 and 2.0, so that the uniformity of the average grain size of the indium target of the tetragonal structure is good. Therefore, the quality of the indium target of the tetragonal crystal structure is improved.

Moreover, since the indium target of the tetragonal crystal structure of the present invention has an oxygen content of not more than 50 ppm, the indium target of the tetragonal crystal structure has less indium oxide, thereby avoiding high resistance of the film due to indium oxide and sputtering. Increased number of arcs Disadvantages such as unevenness of the surface of the target.

Moreover, since the indium target of the tetragonal crystal structure of the present invention has an iron content of not more than 20 ppm, a zinc content of not more than 20 ppm, or a tin content of not more than 20 ppm, the indium target of the tetragonal crystal structure can be used for preparing a thin film solar cell. Reducing defects in the absorption layer, thereby reducing the probability of recombination of electrons and holes, thereby improving the efficiency of photoelectric conversion efficiency.

In addition, the present invention provides that the surface of the indium target of the tetragonal structure which is a planar target comprises crystal planes (101), (103), (200), (112) (110), (211), (202). And (002), and wherein the ratio of the intensity ratio of each crystal face to 12.5% (the ratio of the intensity of each crystal face in the preferred direction) is between 0.5 and 2.0, that is, the indium target of the tetragonal structure The crystal face is close to the state of no preferred direction, so the uniformity of the sputter film is further increased.

Further, the present invention provides an indium target having a tetragonal structure of a planar target subjected to a cold rolling process, the surface of which includes (101), (103), (200), (112), 110), (211), (202), and (002), and the ratio of the intensity ratio of one of the crystal faces to the ratio of the intensity of each of the crystal faces of 12.5% (no preferred direction) is greater than 2, that is, the indium of the tetragonal structure The target has a preferred orientation of the single crystal face to meet the needs of subsequent processes.

Moreover, the present invention provides an indium target having a tetragonal structure of a heterogeneous target, the surface of which includes (101), (103), (200), (112) (110), (211), (202) and (002), wherein the ratio of the intensity ratio of each crystal face to the ratio of 12.5% (the ratio of the intensity of each crystal face in the preferred direction) is between 0.5 and 2.0, that is, the indium target of the tetragonal structure The crystal face of the material is close to the state of no preferred direction, so the uniformity of the sputter film is further increased.

In order to understand the technical features and practical functions of the present invention in detail, and in accordance with the contents of the specification, the drawings and preferred embodiments are further described to illustrate the technical means for the purpose of the present invention.

The source and composition ratios of the samples described in the experimental preparation schemes of the following examples are as follows: Indium raw materials: purity is 4N5 (99.995%).

Optical microscope: Model: Olympus BX51M (origin: Japan).

X-ray diffractometer: Model: Rigaku-UltimaIV (origin: Japan).

Example 1

In this embodiment, a rectangular planar tetragonal crystal indium target is prepared by smelting and rapid cooling during casting, and the detailed preparation method is as follows: First, an indium raw material is prepared and smelted at a melting temperature of 206 ° C. Indium raw material, an indium liquid is obtained, and then a casting method is used to form a tetragonal crystal indium target, wherein the indium target of the tetragonal crystal structure is in a mold, and a cooling device is disposed on one side of the mold, the cooling The apparatus is provided with an inlet end and an outlet end spaced apart from the inlet end such that a cooling medium flows from the inlet end of the cooling device to the outlet end of the cooling device to pass the cooling medium through the cooling device and The mold conducts thermal energy of the indium target of the tetragonal structure, whereby the indium target of the formed tetragonal structure is rapidly cooled from one side, wherein the cooling medium is water, and the water flow rate used is 12 liters/min ( Liter per minute (LPM), the cooling rate is such that the temperature of the indium target of the tetragonal structure is lowered to about 60 ° C within 5 minutes, where the water is stopped and the square is naturally cooled. Indium target temperature close to room temperature until the structure, tetragonal crystal structure of indium target made of a rectangular plane, the After the surface of the indium target having a tetragonal crystal structure of a rectangular plane is polished and surface-treated by isopropyl alcohol wiping, an optical microscope is used to amplify the front, middle, and rear sections of the long side of the indium target of the rectangular plane of the rectangular plane. a face center, wherein the front section is adjacent to the aforementioned inlet end, the rear section is adjacent to the aforementioned outlet end, and the middle section is between the front section and the back end, and the result is as shown in FIG. 1 to FIG. 3, and image analysis is utilized. The software Image-Pro Plus performs subsequent measurements of the average grain size. The aforementioned cross-sectional center means that the cross-section of the indium target of the tetragonal structure has a width of 1/2 and a thickness of 1/2.

The measurement method of the average grain size in this embodiment is to draw four tangent lines on the image map, the four tangent lines are arranged in a m-shape, and the average grain size of the four tangent lines are respectively calculated, and the average crystal of the four tangent lines is calculated. The total average of the particle sizes.

The detailed steps of obtaining the average crystal size of the section center in the previous stage of the present embodiment are as follows: Referring to FIG. 4 to FIG. 7, the image lines L1 to L4 of FIG. 1 are arranged in a square shape. Where A is the intersection of the tangent and the grain boundary, and the distance between two adjacent A is a grain size, and the number of grains, the grain size and the average grain size of each tangent are as shown in Table 1. .

Further, the average grain size of the four tangent lines was averaged, so that the average grain size of the center of the section in the previous stage of Example 1 was 68 μm.

The measurement of the average grain size of the center of the section at the middle and the back of the embodiment 1 is as described above, and will not be described herein. Therefore, it can be known that the average grain size of the center of the section of the front, middle and back sections of Example 1 is 68 μm, 73 μm and 83 μm, respectively, both less than 200 μm, and the ratio of the front to the back of Example 1 is 0.82. The ratio of the back segment to the front segment is 1.22, which is between 0.5 and 2.0, so that the uniformity of the average grain size of the whole of Example 1 is good.

Further, the oxygen content of Example 1 was 9.4 ppm, and the iron content was 3.9. The ppm, tin content is below the detection limit of the method, so it is less than 2.5 ppm and the zinc content is 5.7 ppm.

Example 2

In this embodiment, a rectangular planar indium target having a rectangular planar shape is obtained by a process as described in Embodiment 1, and the main difference is that after the rectangular target tetragonal crystal indium target is obtained, The indium target of the tetragonal crystal structure of the rectangular plane is successively subjected to cold rolling, and the rolling ratio thereof is 40%, whereby the rectangular planar indium target has a (101) crystal face preferred orientation.

Example 3

In this embodiment, a tetragonal rotating indium rotating target is prepared by smelting and rapid cooling during casting, and the detailed preparation method is as described in Embodiment 1, and will not be described herein. The center of the section of the front, middle and back sections of the in-situ rotating target of the tetragonal structure is as shown in Figs. 8 to 10. The average grain size of each section is measured as described in the first embodiment, and is no longer used here. It should be noted that the aforementioned center of the section refers to the center of the cross section of the indium rotating target of the tetragonal structure. Therefore, it can be known that the average grain size of the center of the section of the front, middle and back sections of Example 3 is 127 μm, 151 μm and 141 μm, respectively, both less than 200 μm, and the uniformity of the average grain size of each segment is good. . Moreover, the ratio of the front stage to the back stage of Example 3 is 0.9, and the ratio of the back stage to the front stage is 1.11, both of which are between 0.5 and 2.0, so that the uniformity of the average grain size of the whole of Example 3 is good.

In addition, the oxygen content of Example 1 is 7.2 ppm, the iron content is 9.16 ppm, and the tin content is lower than the detection limit of the method, so it is less than 2.5 ppm, and the zinc content is lower than the detection limit of the method. Therefore, it is less than 1 ppm.

Comparative example

In this comparative example, a rectangular planar indium target is prepared by smelting and natural cooling during casting, and the detailed preparation method is as follows: First, an indium raw material is prepared, and the indium raw material is smelted at a melting temperature of 206 ° C to obtain a The indium solution is subsequently formed by a casting method to form an indium target, and the formed indium target is naturally cooled to room temperature (23 ° C) by air cooling to obtain a rectangular planar indium target, and the rectangular plane is measured using an optical microscope. The average grain size of the indium target. As a result, as shown in Fig. 11, the average grain size was more than 2000 μm. Performing cold rolling on the rectangular planar indium target to refine the average grain size of the rectangular planar indium target, the rolling ratio is 10%, 20%, 30%, 40%, and 50%, and using optical microscopy The average grain size of the rectangular planar indium target at each stage was measured, and it was found that when the rolling ratio was 30% or more, the average grain size was between 500 and 1000 μm.

Test Example 1: Analysis of the preferred direction of the crystal plane of the indium target

In this test example, the rectangular planar indium targets of Examples 1, 2 and Comparative Examples were examined using an X-ray diffraction analyzer to determine the crystal faces of each sample, and the MDI Jade analysis software was used to analyze the strength of each crystal face, and The intensity ratio of the crystal faces of each sample was determined by calculation and intensity ratio with the calibration, and the detailed manner is as follows.

As a result, as shown in FIG. 12, the indium target of the rectangular planar tetragonal crystal structure of Example 1, the rectangular planar indium target of the comparative example, and the X-ray diffraction analysis result of the indium powder as the calibration object, wherein the rectangular shape of the comparative example The planar indium target was subjected to cold calendering treatment and had a calendering ratio of 40%.

In this test example, the MDI Jade analysis software is used to obtain the crystal surface intensity data, thereby obtaining the intensity ratio of each crystal plane to know the rectangular plane indium. The crystal plane direction of the target is shown in Table 1.

Where Ai is the result of analyzing the intensity of each crystal plane by MDI Jade analysis software; Bi is the result of standardization, Bi=Ai/A(101)×100, for example: 249.78/1725.74×100=14.468; Ci is obtained from the database. Reference data for the strength of the calibration; Di is the ratio of the crystal face to the calibration, Di = Bi / Ci, for example: 14.468 / 21 = 0.689; Ei is the intensity ratio of the crystal face, Ei = (Di / Σ Di) × 100, for example, 0.689/7.67×100=8.98%, and Ei can also be expressed as [Ai/A(101)]/Ci/(Σ{[Ai/A(101)]/Ci})×100. If the eight crystal faces shown in Table 1 have no random orientation, that is, the intensity ratio of each crystal face is 12.5%, then the rectangular target tetragonal crystal indium target of Example 1 is The ratio of the intensity ratio of each crystal face to the ratio of 12.5% is 2.0 or less, for example, E(101)/12.5%=13.03%/12.5%=1.042≦2.0, that is, the indium of the rectangular plane of the rectangular plane of Embodiment 1. Since the target is not subjected to cold rolling, the crystal plane of the indium target of the rectangular tetragonal structure is close to the non-preferred direction.

The manner in which the values are obtained is as described above, and will not be described herein. The difference from the foregoing is that the ratio of the intensity ratio of one of the crystal planes of the rectangular planar indium target of the comparative example to the ratio of 12.5% is 2.0 or more, for example, E(101)/12.5%=33.26%/12.5%=2.66 ≧2.0, that is, the rectangular planar indium target of the comparative example has a preferred orientation of the (101) crystal plane due to the cold rolling treatment.

As can be seen from FIG. 12, the X-ray diffraction analysis result of Example 2 is similar to the result of the comparative example, so that the indium target of the rectangular planar tetragonal crystal structure of Example 2 has the preferred direction of the (101) crystal plane, and the rest. The strength of the 7 crystal faces is relatively weak.

Test Example 2: Analysis of the number of arcs generated during the sputtering process of an indium target

In this test example, the rectangular planar indium target of the rectangular plane of Example 1 and the rectangular planar indium target of the comparative example were prepared, and the sputtering power density was changed to determine the number of arcs generated during each sputtering process. The quality of each rectangular planar indium target.

As a result, as shown in FIG. 13, the number of strong arcs or the number of micro-arcs generated during the sputtering of the rectangular planar indium target of the comparative example was significantly higher than that of the tetragonal crystal structure of the rectangular plane of the sputtering example 1. The number of strong arcs generated during the process of the target and the number of micro-arcs, that is, the number of arcs generated during the sputtering process of the indium target of the rectangular planar tetragonal structure of Example 1 is greatly reduced, which is due to the embodiment 1 The average grain size of the indium target of the tetragonal crystal structure of the rectangular plane is significantly smaller than the average grain size of the rectangular planar indium target of the comparative example.

Test Example 3: Quality Analysis of Indium Precursor Film Formed by Rectangular Planar Indium Target

In the test example, the indium target of the rectangular planar tetragonal structure of Example 1 and the rectangular planar indium target of the comparative example were prepared, and the indium precursor film of the example and the indium of the comparative example were formed by sputtering with the following film formation parameters. Precursor film. The quality of the indium precursor film is determined by the strong arc generated by the process of sputtering a rectangular planar indium target and the number of micro-arcs.

The above-mentioned sputtering film formation parameters are a sputtering power density of 3.58 per square centimeter watt (W/cm ² ), an operating pressure of 2.1 milliTorr (mTorr), and an argon flow rate of 50 milliliters per minute (Standard Cubic Centimeter). Per Minute, sccm), the substrate temperature is room temperature. According to the results of strong arc and micro-arc analysis, the number of times the micro-arc is generated during the sputtering of the indium target of the rectangular planar tetragonal structure of Example 1 is Twenty-seven times, in the process of sputtering a rectangular planar indium target of a comparative example, the number of times of micro-arc generation was 462 times, as described in Test Example 2, which was due to the tetragonal crystal indium target of the rectangular plane of Example 1. The average grain size of the material was significantly smaller than the average grain size of the rectangular planar indium target of the comparative example.

In addition, referring to FIG. 14 and FIG. 15, a large amount of micro-arc is generated during sputtering of the rectangular planar indium target of the comparative example, resulting in a large amount of indium microparticles 10 adhering to the surface of the indium precursor film of the comparative example, resulting in The composition and thickness of the indium precursor film of the comparative example were not uniform, and the quality of the indium precursor film of the comparative example was further lowered.

Further, referring to FIG. 16 and FIG. 17, the number of micro-arcs generated by the process of sputtering the rectangular planar indium target of the embodiment is greatly reduced, and the probability of the indium fine particles 20 adhering to the surface of the indium precursor film of the embodiment is reduced. And the size of the largest indium fine particles attached to the surface of the indium precursor film of Example 1 is significantly smaller than that of the surface of the indium precursor film attached to the comparative example, compared to the rectangular planar indium target of the comparative example of FIGS. 14 and 15. The size of the largest indium particles. Based on the above, the composition and thickness uniformity of the indium precursor film according to the present invention are greatly improved, and the quality of the indium precursor film according to the present invention is significantly superior to that of the prior art indium precursor film.

Test Example 4 Performance Analysis of CIGS Thin Film Solar Cells

In the test example, the rectangular planar indium target of the rectangular plane of Example 1 and the rectangular planar indium target of the comparative example were prepared, and the CIGS of the present invention was obtained by the film formation parameters of Test Example 3 and the coating process described below. Thin film solar cells and comparative CIGS thin film solar cells: a molybdenum electrode layer was sputtered on a soda glass substrate. A gallium hydride copper precursor layer is then deposited on the molybdenum electrode layer. A layer of indium metal precursor is then deposited to form a solar absorption precursor reaction layer. The solar absorption precursor reaction layer is subjected to a three-stage high-temperature heat treatment step using a selenium material in a vacuum of less than 10 ^-2 Torr to form a copper indium gallium selenide compound film.

Next, a cadmium sulfide N-type semiconductor buffer layer was formed on the copper indium gallium selenide compound film by a chemical water bath deposition method. The zinc oxide window layer film is further sputtered, and then the aluminum oxide zinc front electrode film is sputtered, and finally the aluminum electrode film is evaporated.

The photoelectric properties of each CIGS thin film solar cell were analyzed, and the results are shown in Table 3 and FIG. Here, the quaternary compound thin film solar cell is a thin film solar cell including only a copper indium gallium selenide compound film as a semiconductor layer.

As can be seen from Table 3, the CIGS thin film solar cell of the present invention is obtained by using the indium target of the rectangular planar tetragonal structure of Example 1, as described above, due to the tetragonal crystal structure of the indium of the rectangular plane of Example 1. The average grain size of the target is much smaller than that of the rectangular planar indium target of the comparative example, so the number of arc generations can be greatly reduced during the sputtering process and the indium particles are prevented from adhering to the sputtering film, thereby greatly increasing the composition of the sputtering film. And the uniformity of the thickness, so the conversion efficiency, short-circuit current density, parallel resistance and fill factor of the CIGS thin film solar cell of the invention are obviously superior to the CIGS of the comparative example. Thin film solar cells.

10‧‧‧Indium particles

20‧‧‧Indium particles

A‧‧‧ intersection of tangent and grain boundary

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an optical microscope image showing the center of a section of a front portion of a tetragonal crystal indium target of a rectangular plane of Example 1.

2 is an optical microscopic image of the center of the section of the midsection of the indium target of the rectangular planar tetragonal structure of Example 1.

3 is an optical microscopic image of the center of the cross section of the indium target of the rectangular planar tetragonal structure of Example 1.

4 is a schematic view showing the measurement of the average grain size of the tangent L1 of FIG. 1.

Figure 5 is a schematic illustration of the measurement of the average grain size of the tangent L2 of Figure 1.

Figure 6 is a schematic illustration of the measurement of the average grain size of the tangent L3 of Figure 1.

Figure 7 is a schematic illustration of the measurement of the average grain size of the tangent L4 of Figure 1.

Fig. 8 is a photomicrograph of the center of the section of the front section of the indium rotating target of the tetragonal crystal structure of Example 3.

Fig. 9 is a photomicrograph of the center of the cross section of the middle portion of the indium rotating target of the tetragonal crystal structure of Example 3.

Fig. 10 is an optical microscope image showing the center of the cross section of the indium rotating target of the tetragonal crystal structure of Example 3.

Fig. 11 is an optical microscope image of a tetragonal crystal indium target of a rectangular plane of a comparative example.

12 is an indium target of a rectangular planar tetragonal structure of Example 1. An indium target of a rectangular planar tetragonal crystal structure of Example 2, a rectangular planar indium target of a comparative example, and an X-ray diffraction pattern of indium powder as a calibration material.

Fig. 13 is a graph showing the relationship between the number of arcs and the power density of the indium target of the comparative example and the example.

Fig. 14 is an optical microscope image showing the magnification of the surface of the indium precursor film of Comparative Example of 5 times.

Fig. 15 is an optical microscope image showing the magnification of the surface of the indium precursor film of Comparative Example of 10 times.

Fig. 16 is an optical microscope image showing the magnification of the surface of the indium precursor film of the embodiment of 5 times.

Fig. 17 is an optical microscope image showing the magnification of the surface of the indium precursor film of the example of 10 times.

Figure 18 is a graph showing the relationship between voltage and current density of a comparative example and a CIGS thin film solar cell of the present invention.

Claims (17)

A tetragonal crystal indium target having an average grain size of between 10 micrometers (μm) and 500 μm, and the surface of the indium target of the tetragonal crystal structure comprises the following crystal planes: (101) (103), (200), (112), (110), (211), (202), and (002), and the ratio of the intensity ratio of one of the crystal faces to the ratio of 12.5% is greater than 2. The indium target of the tetragonal crystal structure of claim 1 has an average grain size of between 10 μm and 400 μm. The indium target of the tetragonal structure described in claim 1 has a ratio of average grain size at both ends of between 0.5 and 2.0. The indium target of the tetragonal structure described in claim 1, wherein the indium target of the tetragonal structure further comprises oxygen, and the indium target of the tetragonal structure has an oxygen content of not more than 50 ppm. The indium target of the tetragonal structure described in claim 1, wherein the indium target of the tetragonal structure further comprises iron, and the indium target of the tetragonal structure has an iron content of not more than 20 ppm. The indium target of the tetragonal structure described in claim 1, wherein the indium target of the tetragonal structure further comprises zinc, and the indium target of the tetragonal structure has a zinc content of not more than 20 ppm. The indium target of the tetragonal structure described in claim 1, wherein the indium target of the tetragonal structure further comprises tin, and the indium target of the tetragonal structure has a tin content of not more than 20 ppm. The indium target of the tetragonal structure described in claim 1 is a planar target. Indium target of tetragonal crystal structure, average grain size (grain The size) is between 10 micrometers (μm) and 500 μm, and the surface of the indium target of the tetragonal structure includes the following crystal faces: (101), (103), (200), (112), (110) (211), (202), and (002), and the ratio of the intensity ratio of the 毎-plane to the 12.5% is between 0.5 and 2.0. The indium target of the tetragonal structure as claimed in claim 9 is a heterogeneous target. The indium target of the tetragonal structure described in claim 9 is a planar target. The indium target of the tetragonal structure described in claim 9 has an average grain size of between 10 μm and 400 μm. The indium target of the tetragonal structure described in claim 9 has a ratio of average grain size at both ends of between 0.5 and 2.0. The indium target of the tetragonal structure described in claim 9, wherein the indium target of the tetragonal structure further comprises oxygen, and the indium target of the tetragonal structure has an oxygen content of not more than 50 ppm. The indium target of the tetragonal structure described in claim 9, wherein the indium target of the tetragonal structure further comprises iron, and the indium target of the tetragonal structure has an iron content of not more than 20 ppm. The indium target of the tetragonal structure described in claim 9, wherein the indium target of the tetragonal structure further comprises zinc, and the indium target of the tetragonal structure has a zinc content of not more than 20 ppm. The indium target of the tetragonal structure described in claim 9, wherein the indium target of the tetragonal structure further comprises tin, and the indium target of the tetragonal structure has a tin content of not more than 20 ppm.