TW201022457A - Transparent conductive zinc oxide display film and production method therefor - Google Patents

Abstract

The present invention concerns a method for the generation of a transparent conductive oxide display coating (TCO display layer), in particular a transparent conductive oxide display coating as a transparent contact for flat panel displays and the like. The TCO display layer is generated by depositing zinc oxide and additionally aluminium, indium, gallium, boron, nitrogen, phosphorous, chlorine, fluorine or antimony or a combination thereof, with the process atmosphere containing hydrogen. These TCO layers can be realized in a particularly simple and cost-effective way compared to ITO. The properties of the inventive TCO layers are nearly as good as those for ITO, regarding high transmittance and low resistance.

Description

201022457 VI. Description of the Invention: [Technical Field] The present invention relates to a method for producing a transparent conductive oxide display coating according to the general term of the scope of the patent application, a patent application scope 9 A general term for a transparent conductive oxide display coating and a use of a transparent conductive oxide display coating as generally described in the scope of claim U.

[Prior Art] Transparent conductive contacts are especially required for optoelectronic applications such as solar cells and solar modules. For this reason, a transparent conductive oxide coating (TCO layer) is mainly used. To date, indium tin oxide (several bismuth) has been mainly used. In addition, especially for flat panel displays, ΙΤ0 has been in the display market for many years. At the same time, however, the oxidation word (ζηο) is enjoying great popularity in industrial use, because the price of dry wood is lower for ΖηΟ, and deposition is more economical than ΙΤΟ. In the past, Ζη〇 has a higher resistance than ΙΤ〇 and has made great efforts to reduce its resistance. In this respect, in particular, the two-part structure of the TCO layer based on the oxidized word appears to be comparable to the properties of the ιτ〇 layer, and the electrical and electrical properties are well known. From US5, G78, 8G4, a structure of a first Zn〇 layer having a net resistance (low conductivity) and a second Zn〇 layer having a low resistance (high conductivity) is known, wherein the first layer is disposed on the cover copper pin. The code (CIGS) is absorbed on the buffer layer (4). Two Zn. The layers were deposited by RF magnetron sputtering in an argon-argon atmosphere or a pure argon atmosphere. 4 201022457 Furthermore, 'US 2005/0109392 A1 discloses a CIGS solar cell structure in which the buffer layer is also covered by the so-called essence of exhibiting high electrical resistance, ie a 'pure ZnO layer (i_Zn〇), and subsequently coated on the pure Zn layer. A Zn layer doped with aluminum and exhibiting a low electrical resistance. A 1 ZnO layer was deposited by RF magnetron sputtering and a Zn0 layer of the same conductivity was deposited by magnetron sputtering of an aluminum doped Zn target. This doped aluminum ZnO target can also be splattered by DC

Shot, which essentially increases the coating rate relative to the RF sputter target. DC

Φ sputtering is used in industrial applications to deposit such conductive Ο Ο: Α 1 layer. The disadvantage of this TCO layer is the fact that it must be structured. The resistance of 5〇〇 cm to 1000 μΩ cm can reach 35〇. Furthermore, more high deposition temperatures. In addition, the conductivity of the doped ZnO is limited to lower temperatures and the transmittance of ZnO can be adversely affected by the dopant. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to make a program usable by which a high conductivity and high transparency can be achieved without special structuring and, in particular, can reach temperatures below 35 (TC). The TCO display layer of Zn〇. In particular, the resistance and transparency of the coating should be comparable to the resistance and transparency of the IT〇 and the transmittance should exceed the transmittance of ΙΤ〇. The method of the present invention is achieved by the use of the TCO display layer of claim 9 and the use of the scope of the patent application. Advantageous embodiments of the objects are subject to the scope of the patent application. It consists of: producing a transparent conductive oxide display coating by depositing zinc oxide and additional sinter, indium, gallium, collar, nitrogen, scale, gas, fluorine or bismuth or a combination thereof under the condition of having an atmosphere including ammonia 201022457 Gallium is the optimum dopant. In this way, a ZnO layer (ZnO: X layer) doped with aluminum, indium, gallium, boron, nitrogen, phosphorus, chlorine, fluorine or ruthenium or a combination thereof is produced.

The inventors of the present invention have surprisingly found that a low resistance and high transmittance of Ζη: χ layer can be produced due to the hydrogen content in the process atmosphere and these properties are as excellent as those of ITO 0 and their properties are high for transmittance. It is better. Since the price of the ZnO target is much lower than the price of the target, the processing cost of the TCO layer is greatly reduced, but the properties of the TCO layer and the quality of the layer remain almost unchanged. The TCO display layers of these inventions can be deposited directly onto substrates such as glass, resins, and the like, or deposited on other layers, such as solar cells or functional layers of displays. In a particularly preferred embodiment, the hydrogen content of the process atmosphere is in the range of 1% to 5% by volume, especially 4% by volume to volume. It is in the range of /〇 and preferably in the range of 6 vol% to 12 vol%. It may work with elemental hydrogen or with an argon-hydrogen mixture. This allows for very cleanliness because undesired carbon will be deposited in an atmosphere containing, for example, methane. Advantageously, the substrate temperature during deposition is at most 35 〇.c, in particular in the range of 100*C to 250 且 and preferably 23 (rc. In such temperature ranges, for example, it can be manufactured to have a thickness of 25 〇 ;) (: the critical temperature and beyond which the resin color will be damaged according to the display of the light sheet L. Advantageously, the hydrogen content in the process atmosphere of 6 201022457 is produced at a low temperature and at a temperature of at least 35 〇〇c for doping GaN-like low-resistance. Different temperature states can be used. By continuous tempering cold deposition or warm deposition, preheating may precede warm deposition. For the method of the invention, warm deposition is preferred. And especially the use of temperature ramps during deposition. Available deposition methods are chemical vapor deposition, physical vapor deposition (such as sputtering and the like), DC sputtering due to high manufacturing yield, good layer quality and low φ equipment cost The best "If the TCO display layer is produced by means of pulsed DC sputtering, since higher power density is possible, the process stability can be improved and thus the deposition rate can be advantageously improved.

Step increase. An increase in process stability can also be obtained by using at least two targets of intermediate frequency sputtering (MF sputtering). Therefore, in the inner valley of the present invention, DC sputtering means that the power density of Dc sputtering, pulsed Dc sputtering, and MF sputtering "DC sputtering" is preferably from 2 w/cm 2 to 2 〇 w/cm 2 . The range _ is particularly in the range of 4 W/em 2 S 15 W/em 2 and preferably in the range of 6 W/cm 2 to 11 W/cm 2 . For these power densities, the resistance and deposition rate are improved. In order to further improve and adjust the electrical resistance and transmittance, the process atmosphere may further contain ruthenium. If a hydrogen source containing a gas mixture (containing hydrogen or a hydrogen compound) is used, the amount of hydrogen can be more precisely controlled by using a larger mass flow controller (mfc). If a nitrogen source containing a chemical compound (containing hydrogen) is used, the treatment of hydrogen, especially in connection with hydrazine, is safer. 7 201022457 It is advantageous to make a ZnO doped layer in which gallium is the preferred dopant. This dopant (Ga) is provided in the range of 3 to 10% by weight, particularly in the range of 4 to 7% by weight of Ga, and preferably having 5.7 % by weight of Ga. It is preferred to dope with a higher percentage of gallium because in this case, the percentage as a dopant can be reduced. The aluminum is suitable for providing a high conductivity, preferably in the range of 0.1 to 5% by weight, preferably 2% by weight, in the case of a dopant. The use of suitable boundary conditions just described allows for the fabrication of transparent conductive oxide display coatings having low electrical resistance and inter-transmittance (maximizing transmission possible). For the protection of transparent conductive oxide display coatings containing Zn〇 mixed with Ming, Indium, Gallium, Butterfly, Nitrogen, Lin, Gas, Fluorine or a combination thereof, the resistance of the coating is at most 1〇〇 In particular, at most _吣cm and preferably at most 45 〇μΩ (ηη and the coating can be deposited at temperatures below c, in particular by the method of the invention. In a preferred embodiment, The transparent conductive oxide display coating has a transmittance of at least 96 5%, especially at least 97, 5% and preferably at least 98.7% at a wavelength of 55 Å. It is a transparent touch for displays and the like of the present invention. The use of a point transparent conductive oxide display coating seeks independent protection. The transparent contact preferably consists only of a transparent conductive oxide display coating. [Embodiment] 8 201022457 Figure 1 shows for use in the method of the present invention The zn〇:Ga layer produced by DC sputtering, the dependence of the resistance on the hydrogen content of the process atmosphere. A Zn〇:Ga layer having a thickness of about 150 nm is deposited on the glass from a planar target having a power density of about 2 w/cm 2 . On the substrate. Of course, it can also be used. Rotatable target. A ceramic target containing zinc oxide and gallium is advantageously used as a target for DC sputtering. This target is a mixed ceramic usually produced by compression or sintering. A metal target composed of a plurality of Zn-Ga alloys of 9% by weight of gallium. By adding oxygen, ZnO:Ga can be sputtered during the reaction. Fig. 1 illustrates a large influence of hydrogen content during DC sputtering. In this embodiment, hydrogen significantly reduces the electrical resistance from about 1270 μΩ cm for Zn〇:Ga sputtered in the absence of hydrogen to about 5〇〇μΩ cm to 6〇〇cm. For 4% by volume and The hydrogen content between Ιό% by volume, there is a broad minimum of resistance" advantageously "hydrogen does not have a negative effect on the transmittance of the TC0 layer. Conversely, increasing the hydrogen content in the process atmosphere will cause a slight transmittance Improvements. To account for the positive effects of hydrogen, 'assuming that the dopant gallium will improve the conductivity of ΖηΟ but produce a lattice defect that increases the resistance, and hydrogen can purify these defects to cause a significant reduction in electrical resistance. Furthermore, it is well documented in the literature. Determining that hydrogen is charged in ΖηΟ When an additional charge carrier is supplied to the supply of the conduction band. The second shows the dependence of the resistance on the power density of the DC sputtering for the ZnO:Ga layer. In this embodiment, the process atmosphere is made to have 10% by volume. In the case of hydrogen content, a ZnO:Ga layer having a thickness of about 3 〇〇nm is deposited on the glass substrate from the planar target. Obviously increasing the power density into 201022457 one step reduces the resistance of the tco smear layer. have

The power density of W/Cm, the resistance is about 400 μΩ cm 1〇% hydrogen' and this is important for about 10 because the higher power density is followed by a higher sputtering rate (see Figure 3) and Better layer quality. In addition, the number of cathodes used in the deposition process can be reduced by higher sputtering rates, or alternatively, the processing speed can be increased because in the production line process, the processing speed must be at each stage of the process (ie, The locking phase, the pre-processing phase, the DC sputtering, the blocking phase, etc.) are equal and the deposition always has the slowest processing speed and thus defines the total production. Figure 3 shows the dependence of dynamic spatter rate on power density for ITO (light square) and Zn〇 (dark dots) layers produced by dc sputtering in the absence of hydrogen in the process atmosphere. The vertical line and the horizontal line indicate the arc discharge limit 'that is, the limit within the range where the arc discharge does not occur and the quality and reproducibility of the arc discharge reducing layer are within. For ZnO, the arc reference discharge limit is more than three times (about 11 W/cm2) than the ITO arc discharge limit (about 3 W/cm2) and for ZnO, a dynamic splash of about 50 nm m/min can be achieved. The rate of incidence is not the dynamic sputtering rate of about 20 nm m/min of ITO. This means that even for a given power density, the sputtering rate of ITO is higher than the sputtering rate of ZnO, and the absolute sputtering rate of ZnO within the arc discharge limit is also higher than the absolute possible sputtering rate of ITO. Therefore, the TCO display layer for processing ZnO is much less expensive than the TCO display layer for processing ITO because the number of cathodes can be reduced or the processing speed can be increased and the ZnO target is less expensive than the ITO target. 10 201022457 For equal power densities, the dynamic sputter rate of Zn〇: Ga in the absence of hydrogen is about 10% higher than the dynamic sputtering rate of Zn〇:Ga in the presence of hydrogen. Figure 4 shows the dependence of transmission on wavelength for Zn 〇 Ga in the presence of hydrogen and no hydrogen versus ιτο. All layers having a layer thickness of about 15 〇 nm were deposited on a glass substrate. In the case where the process atmosphere has 10 radians of hydrogen, a Zn 〇:Ga (dark straight line) layer is deposited by DC 瘳 。. Another ZnO:Ga layer (shallow line) is deposited without hydrogen in the process atmosphere. Both layers are at 23 inches. Deposition under the armpit. It is apparent that 氲 greatly improves the transmittance in the region of short wavelengths and only slightly reduces the maximum transmittance from about 99.50% (ZnO: Ga at 550 nm in the absence of hydrogen) to only about 550 nm. About 98.78% (Zn〇: Ga in the presence of hydrogen at 540 nm). Comparing the case of 10% by volume of hydrogen in the process atmosphere, the ZnO:Ga layer deposited by DC sputtering and the ITO (dark virtual line) deposited at 23 (TC) can be seen as 冗:0; At 98〇11111, an excellent transmission peak of about 98.8% is about 1.6% higher than the peak transmittance of ITO (97.2% at 540 nm). In the case of hydrogen, the transmittance of ZnO:Ga is complete at the wavelength. The visible range (350 nm to 750 nm) is higher than the transmittance of ITO, so that the transmission color of this coating is closer to neutral than the transmission color of ITO (neutral opposite 'deposited by DC sputtering in the absence of hydrogen) The ZnO:Ga layer has a much lower transmittance than the transmittance of ιτο (for short wavelengths). The transmittance peaks of all layers are shown in Table 1. The transmittance data in all the tables below applies to the 150 nm layer thickness. Table 1: Material wavelength [nm] Maximum transmittance [%] ZnO: Ga 550 99.50 in the absence of H2 ZnO: Ga 540 98.78 ITO 540 97.20 in the case of H2 Advantageously, hydrogen is present in the process atmosphere Lower Zn〇: The transmittance of Ga is only slightly dependent on the deposition temperature, and may be slightly higher at higher temperatures. Good transmittance.

For ZnO: A1 (i.e., aluminum-doped zinc oxide), the results of the measurement are not compared in Table 2. In both cases, the hydrogen content in the process atmosphere was 14%' but the substrate temperature was different. Reference

Table 2: Materials ZnO: A1 in the case of h2 ΖηΟ: Α1 3 50 °C

H2 content 14% 14% Power density 8.9 W/cm2 9.3 W/cm2 Resistance 780 μΩ cm 650 μΩ cm The 5th circle is shown at 150 thief layer thickness, for the treatment gas containing hydrogen according to the method of the invention...DC(4) is produced (10) The comparison of the effect or effect of nitrogen on the transmittance of the Zn〇:Ga layer deposited in the absence of hydrogen', that is, the dependence of the transmittance on the wavelength. Compared with Fig. 4, the '5th circle shows the comparison between two ZnO:Ga layers in the presence of hydrogen and no hydrogen under the optimal process parameters of the same layer thickness and maximum transmission of (9). . A detailed comparison in Figure 5 shows an increase in visible light over almost the entire wavelength by the addition of hydrogen' transmission. The Zn0:Ga layer (straight line) was deposited by DC sputtering with 6.0% by volume of hydrogen, 93.7% by volume of argon (Ar), and 0.3% by volume of oxygen (?2). Another Zn〇:Ga layer (dashed line) was deposited with 99.7 vol% Ar and 0.3 vol% 02. The transmittance values shown in Table 3 (also deposited in the absence of hydrogen ITO layer > can clearly see hydrogen improved transmission

Rate 指示 The indicator value is measured relative to a clean, transparent glass. Therefore, the indication values are quite high. In the case of H2, there is _H2

From the above studies, it is apparent that by means of the present invention, a TCO display layer having high transmittance and low resistance can be realized in a particularly simple and cost effective manner compared to ruthenium. Therefore, it is possible to more cost-effectively produce a display in which the &quot;rco layer is used as a transparent conductive contact. These tc〇 display layers can also be used in other devices such as solar cells and the like. It is to be understood that the invention is not limited to the embodiments described above and illustrated herein, but is intended to cover any and all modifications that fall within the scope of the appended claims. For example, although gallium-doped zinc oxide is used to describe all of the results of 13 201022457', it will be apparent to those skilled in the art that other general purpose dopants may be used, such as aluminum, indium, boron, nitrogen, phosphorus, gas, fluorine or antimony. </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; Figure 1 illustrates the dependence of the resistance о + on the hydrogen content of the process atmosphere for the ZnO:Ga layer produced by DC extinction; the second circle shows the Zn0:Ga layer generated by DC sputtering, the resistance The dependence of the rate on the power density; the third circle shows the dependence of the dynamic enthalpy rate on the power density of the IT〇 and Zn〇:Ga layers produced by dc sputtering; The ZnO:Ga layer produced by DC sputtering is compared with the Zn〇:Ga and IT〇 layers deposited in the absence of hydrogen. The transmittance depends on the wavelength. The transmittance of the Zn〇:Ga layer produced by DC subtraction according to the method of the present invention is compared with the ZnO:Ga layer deposited in the absence of hydrogen at a wavelength of 15 Å. [Main component symbol description]

Claims (1)

201022457 VII. Patent Application Range: l A reading for the reading of a transparent conductive oxide display coating by depositing a doped bismuth oxide. One of the transparent contacts of the display and the like is a transparent conductive beta conductive oxide display layer characterized in that the coating is produced in the presence of a transparent conductive oxide display having a process atmosphere comprising hydrogen. 2. The method of claim 1, wherein the hydrogen content in the process atmosphere is in the range of from 1% by volume to 50% by volume, particularly in the range of from 4% by volume to 16% by volume to 12% by volume. In the range of % by volume and preferably in the range of 6. The method according to any one of the preceding claims is characterized in that 100 ec to The substrate temperature during deposition is at most 350, especially in the range of 250 eC and preferably 23 〇.c. 4. A method according to any one of the preceding claims, characterized in that the transparent conductive oxide display coating is produced by linear injection, in particular DC sputtering, pulsed DC sputtering or MF sputtering. 5. The method of claim 4, characterized in that the power density is in the range of 2 WW to 20 W/em, especially in the money of 'W/-n2S 15 W/em2 and preferably 6 (four)^ To ^ 15 201022457 W/cm2 range. 6. The method according to any one of the preceding claims, characterized in that the hydrogen is supplied by a hydrogen source comprising pure hydrogen, a gas mixture containing hydrogen or a compound containing hydrogen, in particular H2 〇, Nh3 Or CH4. 7. The method of any of the preceding claims, wherein the process atmosphere further comprises oxygen, a gas mixture containing oxygen or any chemical compound containing oxygen. The method of any of the preceding claims, wherein the dopant is aluminum, indium, gallium, boron, nitrogen, phosphorus, gas, fluorine or antimony or a combination thereof, preferably gallium. 9. A transparent conductive oxide display coating comprising an oxidized word and a dopant, characterized in that the coating has a resistance of at most 1 〇〇〇μΩ cm, especially at most 6 〇〇cm and preferably at most 450 μΩ cm and the coating can be deposited at a temperature below 35 〇 &lt;c, in particular by the method of any of the preceding claims. The transparent conductive oxide display coating of claim 9, wherein the coating has a transmittance of at least 96.5% at a wavelength of 540 nm, particularly 16 201022457, at least 97.5% and preferably at least 98.8. %. 11. Use of a transparent conductive oxide display coating according to claim 9 or 10, characterized in that the transparent conductive oxide display coating is used for one of transparent contacts of a display and the like . 12. The use of claim 11, characterized in that the transparent contact consists only of the transparent conductive oxide display coating. 17