TW201217557A - Sintered material for zno-mgo-based sputtering target - Google Patents

Abstract

A sintered material for a ZnO-MgO-based sputtering target, which comprises ZnO and MgO, and which is characterized in that Mg is contained in an amount of 3-50 mol% in terms of MgO, an MgO phase (containing an MgO-rich solid solution phase) has the largest crystal particle diameter of 10 μm or less, and the sintered material has a homogeneously dispersed structure. The purpose of the present invention is to provide a sintered material for a ZnO-MgO-based sputtering target, which rarely undergoes the formation of nodules or particles even when the sputtering is carried out for a long period, and which enables the production of a film of which the film composition has excellent in-plane uniformity.

Description

201217557 VI. Description of the Invention: [Technical Field] The present invention relates to a Zn〇_Mg for forming a window material of a Cu-In-Ga-Se (referred to as cms) solar cell: system = useless Sintered body. [Prior Art] In recent years, the development of technology for thin-film solar cells of a CIGS-based solar cell having high conversion efficiency has been progressing, and an oxide semiconductor containing Zn as a main component is known as a window layer material of the solar cell. Patent Document 1 discloses a method of forming a film of a window layer by sputtering a sputtering target such as Zn 〇 or (Zn, Mg) 磁 by a magnetron sputtering method. However, the characteristics of the structure, density, etc. of the sputtering target that affect the sputtering characteristics are not clearly explained. Further, Patent Document 2 discloses that a semiconductor film made of a 〇-type semiconductor such as Zn〇 or ZnMg〇 is used as a dome-shaped window layer of a solar cell. However, the method for producing the ΖηΟ film or the ZnMg0 film is not completely explained. Further, Patent Document 3 discloses that a layer composed of an oxide containing 0 and an oxide of 0 is formed as a window layer of a solar cell by sputtering. Further, it is possible to easily control the composition of the layer by changing the composition of the sputtering target. However, it is described that the oxide layer is formed using Zn 〇 dry, Mg 〇, and a target, and is not formed by a ΖηΟ-MgO alloy target. Also, there is no record at all about the organization. In Patent Document 4, it is described that in the sintered body target containing magnesium oxide as a main component and containing magnesium, the magnesium content is 0.02 to 〇.3 以 in terms of (Zn + Mg) atomic ratio. Further, a zinc oxide-based transparent conductive film having high chemical resistance to acids and bases and low electrical resistance is obtained. However, it is preferable that the oxide sintered body has a composite oxide as long as the composite phase oxide and the composite oxide MgAl2〇4 phase are as small as possible, and it is preferable that only the zinc oxide phase is observed. However, in the case where the dryness of such a structure is used, the arcing is not sufficiently suppressed. Further, Patent Document 5 discloses a target for forming a ruthenium film, which uses zinc oxide as a main component. The component is characterized by containing an additive element having at least one or more element types other than zinc (Zn) and oxygen (〇) as an element type, and the additive element is a compound which does not contain oxygen in the dry. However, as described above, there is a possibility that the target is not contained in the target to generate an electric arc. Patent Document 1: Japanese Laid-Open Patent Publication No. 2008-11-11 pp. Patent Document 2: International Publication No. 2005/069386 Patent Document 3: Japanese Patent Laid-Open Publication No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. 2007/141994. Production In order to solve the above problems, the inventors of the present invention have made an effort to study the results, and the results of the invention are as follows: 2012, 2012, the current raw material powder can be produced by adjusting the raw material powder. As a sintering temperature at the time of pulverization and sintering, a Zn〇-MgO system (4) sintered body having a fine crystal grain size of Mg 〇 phase (Mg0 solid solution phase) is produced, and, when using this recording, The present invention is completed by the present invention. The present invention provides a sintered body for a ZnO-MgO-based sputtering target, which contains Zn〇 and MgO', and is characterized in that Mg contains 3 in terms of Mg〇. ~5〇m〇i%, the maximum crystal grain size of the Mg〇 phase (including the MgO-rich solid solution phase) is 丨〇〆m or less, and has a uniformly dispersed structure. 2. The ZnO-MgO-based sputtering target as described above Using a sintered body, wherein

The maximum crystal grain size of the MgO phase (including the MgO-rich solid solution phase) is below the work. 3. The sintered body of ZnO-MgO sputtering clock according to the above 1, wherein

The Mg 〇 phase (including the MgO-rich solid solution phase) has a maximum crystal grain size of 2 # m or less. 4. The sintered body for a ZnO-MgO sputtering target according to any one of the above 1 to 3, wherein the maximum intensity of the X-ray diffraction peak corresponding to the MgO phase (200) is 11 and corresponds to ΖηΟ When the maximum intensity of the X-ray diffraction peak of the phase (101) is 12, 11/12 is 0.02 or less. 5. The sintered body for a MgO-based sputtering target having a relative density of 95% or more as described above. The ΖηΟ-MgO-based sputtering target of the present invention has an excellent effect of producing a film excellent in in-plane uniformity of a film composition, even if it is produced for a long period of time without causing formation of particles or particles. 201217557 [Embodiment] The sintered body for a Zn〇~Mg〇 sputtering target of the present invention

The MgO is converted to 3 to 50 mol. /. . The reason why the m Mg content is less than 3% or more than 50% by mol in terms of Mg(), the & method functions as a window layer material for a solar cell. Further, the term "Mg" conversion means that the powder of the raw material powder is used for blending. An important point of the sintered body for a Zn〇-Mg-based sputtering target of the present invention is that the maximum crystal grain size of the MgO phase (including the Mg-rich solid solution phase) is 1 m or less, preferably 5 V m or less, more preferably 2 or less m. If the right maximum crystal grain size is too large, large irregularities are likely to occur on the surface, thereby causing abnormal discharge, which tends to increase the generation of particles. In order to reduce the crystal grain size of the Mg 〇 phase (including the Mg-rich solid solution phase), it is necessary to form a suitably pulverized raw material powder and then sinter at a suitable temperature. In addition, the crystal grain size is obtained by grinding the surface of the sample collected from any part of the sintered body, and then analyzing the surface of the sample by using an electron probe microanalyzer (Electron Probe MicroAnalyser: hereinafter, referred to as EpMA). The size of the MgO solid solution phase was measured. In addition, in the case of abnormal discharge or the like, the sintered body can be processed into, for example, a straight cymbal and a thickness of 6 mm, and indium or the like is attached as a solder to the support plate to be sputtered. . An important point of the sintered body for a Zn〇-MgO-based sputtering target of the present invention is 6 201217557, which is a structure in which a Mg 〇 phase (including a MgO-rich solid solution phase) is uniformly dispersed. The reason for this is that if the MgO phase (including the Mg-rich solid solution phase) is locally agglomerated, it is not preferable because it causes problems such as abnormal discharge or film composition deviation. An important point of the sintered body for a ZnO-MgO sputtering target of the present invention is that the maximum intensity of the X-ray diffraction peak corresponding to the MgO phase (200) is 11 and the X-ray corresponding to the ZnO phase (101) is used. When the maximum intensity of the diffraction peak is set to 12, 丨丨/12 is 〇.〇2 or less. Furthermore, the intensity of the X-ray diffraction peak is based on the X-ray diffraction method (X-

RayDifraction: Hereinafter, referred to as XRD), the surface of the sample collected from any portion of the sintered body was measured. If the strength ratio exceeds 11/12 by 〇_〇2, it is not preferable because it causes problems such as balling or abnormal discharge during long-time sputtering and variations in film composition. A more important point of the sintered body for a ZnO-MgO-based sputtering target of the present invention is that the relative density of the sintered body is 95% or more. Furthermore, the relative density is obtained by dividing the absolute density of the burned by the Archimedes method by the theoretical density of the composition. The relative degree of the relative target of the target is low, meaning that there are many internal pores in the target, so When the internal pores are exposed during the splashing process, it is easy to cause a spray or abnormal discharge starting from the periphery of the pore. Therefore, the number of particles on the film is increased, and the surface roughness is advanced in advance, and abnormal discharge or the like starting from the surface protrusion 结 (ball) is likely to occur. This is one of the reasons for the decline in conversion efficiency of CIGS solar cells. EXAMPLES 201217557 Next, examples and comparative examples of the present invention will be described. In addition, the following examples are merely representative examples, and the present invention is not limited to the embodiments, and should be construed as being within the scope of the technical idea described in the specification. (Example 1) A Zn 〇 powder having a purity of 4 N and an average particle diameter of m# m, a Mg 〇 powder having a purity of 3 n and an average particle diameter of 1 // m, 97 mol% of ZnO powder, and 3 mol% of MgO were prepared. The powder is formulated. After the two powders were mixed by a wet ball mill and uniformly dispersed, the powder was finely pulverized by a wet ball mill for about 2 hrs or more without performing calcination to prepare a slurry having a particle diameter of "claw or less." The slurry is granulated and dried by a mist dryer, filled into a 2GG0 metal mold of a predetermined shape, and cold-formed, and subjected to atmospheric pressure in the atmosphere. At this time, the sintering temperature is 12 〇 (rc, the sintering retention time is set. When it is 5: sintering is preferable to (3) generation to i5Q (rc). The reason is that if the temperature is outside the temperature range, the density is difficult to increase. Especially in the case where the sintering temperature is low, the MgO phase tends to exist in a state of agglomeration. The obtained ZnO-Mg ◦ sintered body has a maximum crystal grain size of χ ray diffraction intensity peak intensity ratio 11/12 of 〇〇1 99.5%. X The sintered body is processed into a diameter of 6 忖 and a thickness of 6 Circular plate shape, and ^ into money (four), so that the RF splash bond H force rate is 5 qqw, the ring gas is argon, | [body film see rolling volume flow is 50SCCm, (10) when the pressure is

The rhyme is continuously performed until the (four) period becomes 15 kwh, and the number of protrusions (balls) generated by the surface of H 8 201217557 is 1.2 pieces/cm2. The characteristics of the target and the results of the evaluation of the sputtering are shown in Table 1. [Table 1] Maximum crystal grain size of the target composition MgO phase βτη XRD Peak intensity 11/12 Density % Balls/cm 2 ZnO (mol%) MgO (mol%) Example 1 97 3 5 0.01 99.5 1.2 Example 2 80 20 2 0.02 97.5 1.7 - Example 3 80 20 <0.5 <0.005 98.2 0.5 Example 4 65 35 <0.5 < 0.005 96.8 0.8 Example 5 50 50 10 0.05 95 4.8 Comparative Example 1 80 20 15 0.08 95.5 6.3 Comparison Example 2 80 20 20 0.1 94 11.3 Comparative Example 3 97 3 10 0.06 94.5 6.4 Comparative Example 4 65 35 10 0.05 93 15.3 (Example 2) Preparation of purity 4 N and average particle diameter! " m Zn 〇 powder 'Mg0 powder of pure 3 n and average particle size, formulated with 8 〇 m 〇 1% Zn 〇 powder, 20 mol% of MgO powder. The two powders were mixed by a wet ball mill to be uniformly dispersed, and then calcined at iioot. The calcination is preferably carried out at 1 〇〇 (rc~i3〇〇〇c.) The reason is that if the temperature is too low, there is almost no effect of calcination. On the other hand, if the temperature is too high, the pulverization becomes difficult. The pre-calcined powder is finely pulverized by a wet ball mill for about several hours or more to prepare a slurry having a particle diameter of 1 # m or less. The slurry is subjected to granulation and drying of the shape of the 2000 metal mold by a spray dryer. Perform cold, brother to 疋^ and carry out atmospheric pressure burning 201217557 in the atmosphere. At this time, the sintering temperature is 125 (rc, when. Set the sintering hold time to

The crystal grain size is 2 a m, x 〇·〇2, and the relative density is the maximum entangled diffraction intensity peak intensity ratio of the obtained Zn〇-MgO sintered body of 97.5%. Regarding the structure of the obtained Ζη〇-ton 〇 sintered body, (4) images are shown in Fig. 1, and ΕΡΜΑ images are shown in Fig. 2. It can be seen from the two images that the granular portion is a Mg 〇 phase (including a Mg-rich solid solution phase), and the maximum crystal grain size is m or less, and is uniformly dispersed in the target surface. Under the same conditions as in Example 1, the sintered body was processed, and the bond was dried to conduct lamp spattering, and the number of protrusions (both balls) generated on the dry surface was counted, which was very small. Good results. ’. (Example 3) A Z n 〇 powder having a purity of 4 N and an average particle diameter of m, a Mg 〇 powder having a purity of 3 N and an average particle diameter Um, 〇_1% of Zn 〇 powder, and 20 mol% of MgO powder were prepared. Provisioning. The two powders were mixed using a wet ball mill to uniformly disperse them at 1100. . Pre-burning. The pre-fired powder was finely pulverized by a wet ball mill into a temple of a size of i or less to prepare a polymer having a particle diameter of i or less. The slurry was granulated and dried by a spray dryer, and filled into a 2GG0 metal mold having a predetermined shape to be cold-formed, and subjected to atmospheric pressure sintering in the air. At this time, the sintering temperature was (1) generation, and the sintering holding time was set to 5 hours. The maximum crystal grain size of the obtained ZnO-Mg〇 sintered body is less than 17.5 to 201217557 m, and the X-ray diffraction intensity peak intensity ratio U/i2 is less than 〇 〇〇5, and the relative density is 98.2%. Under the same conditions as in Example 1, the sintered body was processed and a sputtering target was formed to perform RF sputtering, and the number of protrusions (balls) generated on the surface of the target was counted to be very small, 0.5/cm 2 . For good results. (Example 4) A Zn 〇 powder having a purity of 4 N and an average particle diameter of ?, a MgO powder having a purity of 3 n and an average particle diameter Um was prepared, and the mixture was blended with 65 m〇i% of Zn〇 powder and 35 mol% of MgO powder. The two powders were mixed by a wet ball mill to be uniformly dispersed, and then calcined at llOOt. The calcined powder was subjected to fine pulverization for about 20 hours or more by a wet ball mill to prepare a pulverized body having a particle diameter of less than or equal to the claw. The granules are granulated and dried by a spray dryer to a metal mold of a predetermined shape, which is cold-formed and subjected to atmospheric pressure in the atmosphere.

Knot. At this time, the sintering temperature was 135 n: and the sintering holding time was set. The maximum crystal grain size of J is less than 〇. 5 from 11/12 is less than 〇·〇〇5, and the relatively dense ZnO-MgO sintered body m has an X-ray diffraction intensity peak intensity ratio of 96.8%. Under the same conditions, the sintered body is processed in the embodiment - the ancestor - the public key, so as to carry out RF sputtering, and count the number of protrusions (both balls) generated on the target surface, which is very small. After 8 ^ 2 ' α 夕 夕 夕 · 8 八 m, is a good result. (Example 5) Preparation of purity 4 N and flatness! The ten-averaged 1/zm Zn0 powder, the purity 3n 201217557 and the average particle size of the Mg0 powder were formulated with 5〇111〇丨% of Zn〇 powder and 50% by mole of MgO powder. The two powders were mixed by a wet ball mill to be uniformly dispersed, and the powder was finely pulverized by a wet ball mill for about 2Q to prepare a pulverized body having a particle diameter of 1 Vm or less. The slurry was granulated and dried by a spray dryer, filled into a 20 M metal mold of a predetermined shape, cold-formed, and subjected to atmospheric pressure sintering in the air. At this time, the sintering temperature was 150 (rc, and the sintering holding time was set to 5 hours. The maximum crystal grain size of the obtained Zn〇-Mg0 sintered body was ... m, and the x-ray diffraction intensity peak intensity ratio was 11/12. 5, the relative density is 95%. Under the same conditions as in the first embodiment, the sintered body is processed and made into a residue, thereby performing RF_, counting the number of protrusions (balls) generated on the (four) plane, as little as 4· 8 八 m2, which is a good result. (Comparative Example 1) A ZnO powder having a purity of 4 N and an average particle diameter of 1 m, a Mg 〇 powder having a purity of 3 and an average particle diameter Um, of 8 〇 111 〇 1% was prepared. Zn〇/2 (1% of Mg 〇 powder is blended. n) The two powders are dry-mixed and uniformly dispersed, and the powder is pulverized in a dry manner for about 20 hours or more without calcination. The following powders are filled into a 200-mold metal mold of a predetermined shape and subjected to cold-forming at atmospheric pressure. At this time, the sintering temperature is 1200 〇c, and the sintering holding time is set to 5 hours. 201217557 95.5% The obtained Zn〇~Mg〇 sintered body has a maximum crystal grain size of 15/zm, x-ray The diffraction intensity peak intensity ratio 11 / 12 is G.G8, and the relative density is the same as in the case of Example 1, the sintered body is processed, and the machine is dried to prepare the RF clock, and the protrusion generated on the dry surface is counted. The number of objects (balls) increased to 6.3/cm2. (Comparative Example 2) A Zn 〇 powder having a purity of 4 N and an average particle diameter, a Mg 〇 powder having a purity of 3 n and an average particle diameter of 2 // m was prepared at 8 〇. M〇1% of Zn〇 powder and 20m〇% of Mg0 powder are blended. After mixing the two powders in a dry manner, the powder is uniformly dispersed, and the powder is dried without drying for about 2 hours or more. The pulverization is carried out to produce a powder of the following shape: The powder is filled into a 200 mm metal mold of a predetermined shape to be cold-formed and subjected to atmospheric pressure sintering in the atmosphere. At this time, the sintering temperature is "赃, and the sintering holding time is set to 5 hours. The maximum crystal grain size of the ZnO-MgO sintered body was 2 〇〆 m, the x-ray diffraction intensity peak intensity ratio 1...2 was 〇1, and the relative density was (4). The same conditions as in Example 1. Next, processing the sintered body, and making it dry and dry > (foot and rF sputtering, counting The number of protrusions (balls) produced on the dry surface increased to 113 octels. (Comparative Example 3), Zn 〇 powder with a purity of 4 N and an average particle diameter of j " m, purity 3 N and average The particle size of 吣0 powder is formulated with 97 mol% of ZnO powder and 3 201217557 mol% of Mg 〇 powder. The two powders are mixed by σ to form a uniform dispersion by a wet ball mill, and then pre-burned without The wet ball mill grinds and pulverizes the powder to prepare a slurry having a particle diameter of m# m or less. The filling and the filling were carried out until the normal pressure was set to 5, and the slurry was granulated and dried by a spray dryer, and the shape of the 200 0 metal mold was cold-formed and kneaded in the atmosphere. At this time, the sintering temperature is 1 〇〇 (rc, when the sintering is maintained. The crystal grain size is 10 / / m, and the relative density of X 〇 · 〇 6 ' is the maximum junction ray diffraction of the obtained ZnO-Mg 〇 sintered body. The intensity peak intensity ratio of 1 1 / 12 is 94.5%. Regarding the structure of the obtained ZnO-Mg 〇 sintered body, the image is shown in Fig. 3, and the ΕΡΜΑ image is shown in Fig. 4. It can be seen from the two images that the granular portion is The Mg0 phase (including the Mg-rich solid solution phase) also has its largest crystal grain:: over l〇Wm, and a part of it is agglomerated in the target surface. Under the same conditions as in Example 1, the sintered body is processed and made. The net plating target is used for RF sputtering, and the number of protrusions (矣 balls) generated on the target surface is increased to 6.4/cm2. (Comparative Example 4) Preparation of purity 4 N And the average teaching; ^ 1 , j workers 1 in Zn 〇 powder, purity 3, and the average particle size of 1 / zm of Mg 〇耠 * ~ ln / as end of the ' with 65 mol% of ZnO powder, 3 5 The mol% of the MgO powder is blended. The wet ball mill is used to mix the two powders and the whole structure is evenly dispersed, and then the wet ball mill is used to push the powder to the dragon. ^ J does not enter the micro-grinding for about 20 hours or more.

CN 201217557 Produce a particle size of 1 "m or less. The ruined body was granulated and dried by a spray dryer, and filled into a 200-m metal mold of a predetermined shape to be cold-formed, and subjected to atmospheric pressure sintering in the atmosphere. At this time, the sintering temperature was ll00 〇 c, and the sintering holding time was set to 5 hours. The obtained ZnO-MgO sintered body has a maximum crystal grain size of 1 〇 " m, and the x-ray diffraction intensity peak intensity ratio U/丨2 is 〇.〇5, and the relative density is 93%. The sintered body was processed under the same conditions as in Example 1 to form a sputtering target, and RF sputtering was performed, and the number of projections (balls) generated on the surface of the target was counted and increased to 15.3 / cm 2 . [Industrial Applicability] The Zn0_Mg-based sputtering target obtained by the present invention has the following excellent properties because the Mg 〇 phase (including the Mg-rich solid solution phase) has a maximum crystal grain size & Effect: When a film is formed by sputtering using this time, there is almost no abnormal discharge even after a long period of time, and a film having excellent in-plane uniformity of the film composition can be obtained. It is especially suitable as the first absorbent layer for thin solar cells and the window layer material for CIGS four (four) solar cells. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an SEM image of a surface of a target J heart of Example 2 of the present invention. Figure 2 is an SEM image of the target surface of Comparative Example i. Fig. 3 is a second embodiment of the present invention <ΕΡΜΑ image of the surface of the crucible Fig. 4' is a comparative example! The image of the dry surface. [Main component symbol description] None 15

Claims (1)

201217557 VII. Patent application scope: 1. A sintered body for ZnO-MgO sputtering target containing Zn〇 and MgO, characterized in that Mg contains 3~5〇m〇l% in MgO conversion, and MgO phase (including rich The Mg0 solid solution phase has a maximum crystal grain size of 10 μm or less and has a uniformly dispersed structure. 2. The Zn 〇 - Mg 〇 sputtering target sintered body of claim 1 wherein the Mg 〇 phase (including the Mg-rich solid solution phase) has a maximum crystal grain size of 5 or less. 3. The sintered body for a ZnO-MgO-based sputtering target according to the first aspect of the patent application, wherein the MgO phase (including the MgO-rich solid solution phase) has a maximum crystal grain size of 2 or less. 4. The sintered body for a ZnO-MgO-based sputtering target according to any one of claims 1 to 3, wherein the maximum intensity of the X-ray diffraction peak corresponding to the MgO phase (200) is set to 11, When the maximum intensity of the X-ray diffraction peak corresponding to the ZnO phase (101) is 12, 11/12 is 〇.〇2 or less. 5. The ZnO-MgO-based bond dry sintered body of the fourth application of the patent application has a relative density of 95% or more.