TW200419003A - Method for producing silver alloy reflective film, sputtering target, and silver alloy film - Google Patents

Abstract

The present invention provides a method for producing a silver alloy reflective film having a high reflectivity and a good bonding with a substrate, and a good corrosion resistance, a sputtering target, and a silver alloy film. A silver alloy film contains silver as a main ingredient, 0.1 to 4.0 at% of Au, and 0.1 to 2.5 at% of Sn. A sputtering target has a same composition as such an alloy. A silver alloy film containing oxygen is produced by using such a target material and Ar as a sputtering gas, and at least an addition gas selected from O2, H2O, or H2+O2, etc.

Description

200419003 (1) Description of the invention [Technical field to which the invention belongs] The present invention relates to a silver alloy thin film, a sputtering target, and a method for manufacturing a silver alloy thin film used for a reflective film of a flat panel display (FPD) such as LCD, organic LED, and the like. [Prior art] In the past, A1 and its alloys (A1-Nd series, etc.) were used as reflective films on display devices. However, the short-wavelength part with visible light has low reflectance and poor chemical resistance and heat resistance. Disadvantages such as protective film. For these reasons, silver films have also been tried out. This silver film has poor corrosion resistance, which will cause discoloration due to sulfur components and chlorine gas in the air, resulting in a decrease in reflectance. In addition, its contact with the substrate is not good, so film peeling and pinholes are likely to occur ( pinhole) and other phenomena. Therefore, an adhesion layer between the upper protective film and the substrate is necessary. In order to improve the corrosion resistance of this silver thin film, proposals have been made to use a silver Pd alloy and a silver PdCu alloy (for example, Patent Documents 1 and 2). However, the adhesion between these alloys and the substrate is not high, and therefore an adhesion layer such as a metal oxide is required. Patent Document 1 Japanese Patent Application Publication No. 2000-109943 (Scope of Patent Application, etc.) Patent Document 2 Japanese Patent Application Publication No. 2000-285517 (Scope of Patent Application, etc.) [Summary of Invention] -5- (2) (2 200419003 [Problems to be Solved by the Invention] The problem of the present invention is to provide a silver alloy reflective film having high reflectivity, adhesion to a substrate, and excellent corrosion resistance in order to solve the above-mentioned problems of the prior art. A sputtering target for manufacturing such an alloy thin film and a method for manufacturing a silver alloy thin film. [Means to Solve the Problem] The present inventors have found out an effective method for adding Au and S η in order to solve the problem of low corrosion resistance and low adhesion of pure silver thin films and improve their reflection characteristics, and completed the present invention. The invention contained in claim 1 is a silver alloy reflective film, which is characterized in that: silver is a main component, Au is a minor element, and Sn is a third element, wherein the content of Al is 〇 ·; [~ 4.00at% , Sn content is 0.1 ~ 2.5 at%. The reflectivity of this silver alloy film in the visible light range (wavelength 400 ~ 70nm) is more than 90%, and its corrosion resistance and adhesion to the glass substrate are good. Beyond this range, the silver alloy film cannot have both reflectivity, corrosion resistance and adhesion. In this reflective film, the corrosion resistance mainly comes from the addition of Au; and the adhesiveness mainly comes from the addition of Sn. The invention described in claim 2 is characterized in that oxygen is added to the above-mentioned reflective film as its fourth element, and its content is 0.1 to 3. Oat%. A film having an oxygen content within this range has good adhesion to the substrate. The invention recited in claim 3 is characterized in that the reflective film is a laminated film formed by laminating the reflective film and the silver alloy thin film and the metal oxide film. The invention contained in claim 4 is a silver alloy sputtering target, which is characterized by: -6-(3) (3) 200419003 with silver as the main component 'Au as a minor element and sn as a third element, of which 8-11 content 0.1 ~ 4. (^%, 311 content is 0.1 ~ 2.5 "%. Because a leather material with an Au content of 0.1 ~ 4.0at% and a Sn content of 0.005 ~ 2.5at% is used for sputtering , Make the silver alloy thin film reflectance in the visible light range (wavelength 400 ~ 700nm) reach 90%, and have corrosion resistance and good adhesion to the substrate. Outside this range, the silver alloy thin film cannot have both reflection The invention set forth in claim 5 is a method for manufacturing a silver alloy thin film, characterized in that the silver alloy sputtering target is used as a target material, and Ar gas is used as a sputtering gas. At least one of oxygen-containing gases such as .20 or H2 + 02 is selected as an additive gas for sputtering; to produce silver as the main component, the All content is 0.1 to 4.0 Oat%, and the Sn content is 0.1 to 2.5 at. %, A silver alloy film with an oxygen content of 0.1 to 3.0 at ° /. In particular, it is formed when the substrate temperature is low. In the case of a film (substrate temperature below 100 ° C), a silver alloy thin film with good adhesion to the substrate can also be effectively produced by this method. The invention described in claim 6 is characterized in that, in the method for manufacturing an alloy thin film, The oxygen-containing gas is supplied only at the initial stage of film formation caused by sputtering. The invention described in claim 7 is a method for manufacturing a silver alloy thin film having a laminated structure, characterized in that, in the method for manufacturing an alloy thin film described above, A silver alloy thin film is formed by laminating a metal oxide film as a base layer, but an additive gas is supplied or not supplied to produce a silver alloy thin film during sputtering. Examples of such films having a laminated structure include a silver alloy thin film and ITO, IZO (4) (4) (4) 200419003 laminated structure of one (or more) doped with antimony oxide tin oxide, lead oxide-alumina, titanium oxide and other metal oxide films. In the case of a manufacturing method in which a reflective film is used as the anode of an organic LED, it is necessary to adjust the work function with the hole transporting layer, so it is effective to obtain a reflective electrode film with good hole injection efficiency. In addition, in the case where a subordinate oxide is used as the base layer, a silver alloy thin film with good adhesion to the substrate can be provided without using the above-mentioned additional gas such as 〇2, HhO, or H2 ++ 〇2. Because the silver alloy whip material of the present invention contains Sn, and due to the trace use of the above-mentioned addition gas such as 02, H2O, or H2 + 02, the composition of Sn02 is generated in the film. This Sn02 component will become the same as the substrate As a binder, it is easy to provide a silver metal film with good adhesion. Glass' silicon, or plastic film can be used as a substrate. Due to the use of the above-mentioned silver alloy target material, it is possible to provide a silver alloy thin film with good corrosion resistance and adhesion and high reflectivity. Although the contents in this booklet are mainly used as reflective films, they can also be used as wiring films because the obtained silver alloy film has a resistivity of 9 β Ω cm or less. [Embodiment] (Example 1) The following targets are set in each sputtering chamber: silver is the main component, 0.94at% (1.7wt%) of Au is added, and 1.84at% (2.0wt%) is added The material of Sn is the material of lb of the Yiyitan Mine 1. It is made of silver, with 0.5 5at% (l.Owt%) of Au and l.lOat% (1.2wt%) of sn. The material is the sacrifice material 2b of the second sputtering chamber 2; it contains silver as the main component, and 0.2 8at% (0.5 wt%) of Au is added, and 0.4 6at% (0.5 wt%) of -8- (5) ( 5) The target of 200419003 S η is the target 3 b of the third sputtering chamber 3. Not shown in the figure, there is a preparation room equipped with a vacuum exhaust system beside the first sputtering chamber 1 to form a combination that can send the substrate 7 to the first sputtering chamber 1. Ar gas 200SCCM ′ oxygen 0.5SCCM (〇2 partial pressure is 2.67xl (T3Pa)) is introduced into the first sputtering chamber 1 and a DC current of 500w (power density 1W / cm2) is passed through the target lb. The sputtering pressure is about 〇. .667Pa. The substrate transfer tray 6 equipped with the cleaned glass substrate (Corning 1 7 3 7) 7 is sent to the first sputtering chamber 1 at a speed of 20 cm / mi from the preparation room, at room temperature and 2 Pass through film formation at 0 ° C. Discharge ends when the transport tray 6 passes the material 1 b, and the transport tray is returned to the preparation room. A silver alloy film 1-1 with a thickness of 150 nm is made on the substrate 7. In the second sputtering chamber 2 and the third sputtering chamber 3, the same operations as described above are performed, and a silver alloy film 1-2 and a silver alloy film 1-3 having a thickness of 150 nm are fabricated on respective substrates. It is a continuous (i η 1 ine) film-forming method, but it can also be made by a single-cavity (batch) -type or leaf-type film-forming device. The reflection of the obtained silver alloy film 1_1 ~ bu 3 The reflectance, adhesion, corrosion resistance, electrical resistance, and etchability were investigated. The reflectance is based on the Si substrate, and the spectroscopic light is used in the visible light range (wavelength 400 to 800 nm). The adhesiveness was measured by using a cross-cut method to make a cut in the film with a cutter to make a 25-mm square (5x5) with a size of 5 mm2, and then using an adhesive tape (24M made by 3M). Checkerboard test, check the number of unseparated cells in the 25 grid to evaluate. The corrosion resistance is evaluated by placing the substrate with a -9-(6) 200419003 silver alloy film in a 5% NaCl solution for 96 hours. To observe the corrosion status. The resistance is measured using a 4-probe resistance tester (manufactured by Mitsubishi Chemical). The etching property is determined by a general photo-resist process using phosphoric acid: nitric acid: water = 4 : 1: 5 ratio of the mixed solution is etched for etching and evaluated. For comparison, an APC (silver-0.9wt% Pd-1 · 0wt% Cu) film was also made and evaluated the same. The results are shown in Table 1 .: (Table 1 )

Item \ Silver alloy film \ Filming temperature CQ Film thickness ㈧ R (° / 〇) 480nm (Ref: Si) Adhesion and corrosion resistance P (// Ωατι) Etching characteristics M / glas M / I / glas APC Room temperature 1500 235 3/25 25/25 0 4.6 0 (Silver-0.9Pd-1.0 Cu) 200 1500 225 7/25 25/25 0 4.1 〇 Silver alloy film 1-1 Room temperature 1500 232 25/25 25/25 0 8.3 〇 (Silver-l.7Au-2.0Sn) 200 1500 226 25/25 25/25 0 5.5 〇 Silver alloy film 1-2 Room temperature 1500 239 25/25 25/25 0 7.0 〇 (Silver-l.0Au-l. 2Sn) 200 1500 230 25/25 25/25 0 5.5 〇 Silver alloy film 1-3 Room temperature 1500 242 20/25 25/25 0 4.6 〇 (Silver-0.5Au-0.5Sn) 200 1500 235 25/25 25 / 25 0 4.3 〇

The reflectance R (%) in Table 1 is represented by 値 η of 4 8 ο ηηι; and M in the adhesiveness refers to a silver alloy film, and I is IT0 in the following Example 4 (7) (7 ) 200419003 film base layer. As clearly shown in Table 1, any silver alloy film has a reflectance equal to or higher than that of APC. The silver alloy films 1-3 with the smallest additions of Au and S η had the highest reflectance. This added amount is expected of the effective content of the additive. 方面 In terms of adhesion, the adhesion between any silver alloy film and the substrate is better than that of APC. It is presumed that this is due to the reaction between the Sn element in the target and the 02 gas added during sputtering to generate Sn02. In addition, Auger analysis was performed on the silver alloy film 1-1 to 1-3 obtained by the above-mentioned room temperature film formation, and the same silver alloy film as described above was obtained by changing only the amount of oxygen introduced for room temperature film formation. The oxygen content in the obtained silver alloy film is shown in Table 2:

-11-(8) 200419003 (Table 2) Target material oxygen introduction amount (Pa) Molybdenum content (at%) silver_l.7Au-2.0Sn 2.67χ 10 " 3 0.7 ~ 1.0 1.33X10 '2 0.8 ~ 1 · 5 6.65χ10 * 2 2.0 ~ 3.0 2.67χ 1 O'3 (a) 0. 1 ~ 0 · 8 Silver-l.〇Au-1.2Sn 2 · 67χ 1 (Γ 3 0.5 ~ 0.8 1.3 3 X 1 0 " 2 0.7 ~ 1.2 6.65χ 1 Ο-2 1 · 5 ~ 2.0 silver-0.5Au-0.5Sn 2 · 67χ 1 0 · 3 0.1 ~ 0.5 1.33xl0 · 2 0.5 ~ 1 · 0 6.65χ 1 Ο'2 1 .2 ~ 1.8 (Note) Only introduce oxygen at the initial stage of film formation. At this time, the film thickness of the initial layer is less than 300 A. As shown in Table 2, it is obtained according to the film formation conditions of the present invention. Although the oxygen content in the silver alloy film changes depending on the amount of oxygen added during film formation, it also ranges from about 0.1 to 0.3 at%. In particular, due to the closeness to the glass substrate, The control on the interface is very important. Even if the method of making a silver alloy film by introducing oxygen only in the initial stage of film formation, it can be concluded that the film composition only has an oxygen content of 0.1 to 0.3at% in the initial layer and is fully equipped with close contact. In terms of corrosion resistance, silver alloy films 1-1 ~ 1-3 are immersed in 5% NaC l After 96 hours in the solution, there is no change in terms of observation, showing good corrosion resistance -12- (9) (9) 200419003. For comparison, the corrosion resistance test of pure silver was also performed, and the result was 24 hours After the surface gloss disappears, the corrosion resistance is not good. In terms of resistivity, the silver alloy film 1_1 with a large amount of Sn is 8. 3 // Qcm in the case of film formation at room temperature, and the alloy film in other cases even has Lower resistivity, so these alloy films can also be used as wiring films, and the availability is quite high. The silver alloy film 1-1 ~ 1-3 is about etchable, it is about; melting at 100nm / min Speed 'to obtain a good patterning shape. Since it can cope with the resist process, it can be seen that it is a film with good alkali resistance and organic solvent resistance. (Example 2) H20 (H20) The gas partial pressure is 2.67xl (T3Pa) instead of the added gas in Example i, and the others are made according to the method of Example 1 to produce silver alloy films 2.1, 2-2, and 2-3. The obtained film is subjected to the same procedure as in Example 1 The same physical properties were investigated, and the results were reflected in reflectance, adhesion, corrosion resistance, resistivity, and etching. Sexual etc. are good. (Example 3) is added to the gas substitution Η0〇2 embodiment} In the embodiment, the other 3-1, 3-2, making the silver alloy films in accordance with the method of Example 1. The h2 gas system was introduced as an Ar gas containing 3% ytterbium, and the 〇2 gas was introduced at a partial pressure of 2.67x1 (T3Pa.) The same physical property survey as in Example 1 was performed on the obtained film. As a result, the reflectance, Adhesiveness, corrosion resistance, electrical resistance-13- (10) (10) 200419003 are excellent in terms of coefficient and etching processability, etc. (Example 4) ITO (In2〇3 + 10wt% Sn〇2) target is the first In the figure, targets 1 b and 3 b of the first sputtering chamber 1 and the third sputtering chamber 3; Au containing 0.28 at% (0.5 wt%) as the main component, and 0.4 6 at% (0.5 wt%) of the silver alloy target of Sn is the target 2b of the second sputtering chamber 2. According to the method described in Example 1, but without the use of added gas, an ITO film (15 nm) / silver alloy was fabricated on the glass substrate 7. Film 1-3 (1 5 Onm) / ITO film (15nm) laminated structure film. The reflectance of the obtained laminated structure film was measured in the same manner as in Example 1. The obtained reflectance film had a reflectance of 235% ( Relative to Si), it has the same high reflectance as the silver alloy film alone. Adhesion and corrosion resistance are also as good as those of Example 1. In addition, the surface of the needle kt S 旲 is flat. The properties were investigated by AF Μ, and the results R ma X = 7.0 nm and Ra = 0.7 nm were both very good. The reflective film obtained in this embodiment is particularly suitable as an anode of an organic LED. In addition, an APC film / ITO film was produced in the same manner as described above. And silver alloy film 1-1 ~ 1-3 / ITO film laminated structure film, and the adhesion of these films was measured. The results are shown in Table 1. The adhesion of each film was good. Examples 1 to 4 The method described is only for the film formation on a substrate at room temperature and a heated base plate (20 ° C), but in the case of film formation on a substrate at other temperatures (350 ° C), or room temperature The same highly reflective film can be obtained in the case of after-anneal after film formation. That is, good results can be obtained between room temperature and 350 ° C. -14-(11) 200419003 (Comparative Example 1)

With silver as the main component, the addition of 0 · 9 4 a t% (1 · 7 w t%) of Au is the first metal plating room 1 in Figure 1? E material 1 b; the target material with Ag as the main component added with 0.5 5 at% (1.0 wt%) is the target material 2 b in the second sputtering chamber 2; the main component with silver is added with 0 · The target of 2 8 at% (0.5 wt%) Au is the target 3 b of the third sputtering chamber 3. The target device was formed into a film under the same conditions as in Example 1 to prepare a silver alloy film 150A on a glass substrate. However, the amount of oxygen introduced was changed to OPa, 2.67xl (T3Pa, 6 · 65 χ 1 0 · 2 Pa) for film formation. The characteristics of each of the obtained silver alloy films were investigated in the same manner as in Example 1, and the results were reflected in The rate, corrosion resistance, and etching properties are all good, but the adhesion is as shown in Table 3, and it is not good even if the amount of oxygen introduced is increased.

-15- (12) 200419003 (Table 3) Adhesiveness of oxygen introduction amount of leather materials (Pa) (for glass substrate) Silver-0.94at% (1.7 wt%) Au 0 0/25 2 · 67χ 1 0 · 3 0/25 6.65χ 1 O'2 0/25 silver-0.55at% (l.0wt%) Au 0 0/25 2.67χ 1 O'3 0/25 6.65χ 1 O'2 0/25 silver-0.2 8 at% (0 · 5 wt%) A u 0 0/25 2.67x 1 0-3 0/25 6.65χ 1 O'2 0/25

(Comparative Example 2) The silver-based material with 1,84at% (2.0wt%) of Sn as the main component is the target 1b of the first sputtering chamber 1 in Fig. 1; the main component is silver The target material with Sn added to 1.1 Oat% (1.2 wt%) is the leather material 2b of the second sputtering chamber 2; with silver as the main component, 0.46at% (0.5wt%) is added. The target of Sn is the target 3 b of the third sputtering chamber 3. After the target device was formed, a film was formed on the glass substrate under the same conditions as in Example 1 and 1,500 persons were made of a silver alloy film. However, the amount of oxygen introduced was changed to 0pa, 2.67χ 1 (r3pa, 6 65 χ 1 〇_2pa, and film formation was performed. TtThe characteristics of each of the obtained silver alloy films were investigated in the same manner as in Example 1. The results are reflected The rate, adhesion, and etching are all good; but the corrosion resistance -16- (13) 200419003 is not as good as shown in Table 4. (Table 4) The amount of oxygen introduced into the target component) Pa) --- Health ) 5% NaCl fiber test) Silver-1.84at%) 2.0wt%) Sn 0 Surface gloss disappears after 24 hours 2.67xl0'3 Surface gloss disappears after 30 hours 6.65 × 10'2 After 30 hours, it is flat and flat, silver -1.1 (^%) 1.2 plus ° / 〇) 311 0 The surface gloss disappears after 24 hours 2.67 × 10 · 3 The surface gloss disappears after 24 hours 6.65 × 10 · 2 The surface gloss disappears after silver-0.46at%) 0.5wt%) Sn 0 The surface gloss disappears after 24 hours 2.67 × 10 · 3 The surface gloss disappears after 24 hours 6.65 × 10'2 The surface gloss disappears after 24 hours [Effect of the invention] According to the present invention, the use of the above-specified silver alloy target material can provide: Silver alloy film with good adhesion to glass substrate, good corrosion resistance, etching processability, and local reflectivitySince the resistance 値 of the silver alloy film is very low, the reflective film can also be used as an electrode film or a wiring film. [Brief description of the drawings] [FIG. 1] A structural diagram of a continuous sputtering (Inline Sputtering) device used in the embodiment of the present invention. -17- (14) (14) 200419003 [Explanation of symbols] 1: First sputtering chamber 2: Second sputtering chamber 3: Third sputtering chamber 1a, 2a, 3a: cathode lb, 2b, 3b: target 1 c, 2 c, 3 c: power supply

Id, 2d, 3d: Gas introduction system 4, 5: Valve 6 = Substrate transfer tray 7: Substrate

-18-

Claims (1)

(1) (2004) 200419003, patent application scope 1 · A silver alloy reflective film, which is characterized in that it is made of a silver alloy containing silver as the main ingredient and containing Al and Sn, the Au content is onoat%, and the Sn content is 0.1 ~ 2.5at%. 2. The silver alloy reflective film as described in item 1 of the claim, further comprising 0.1 to 3.0 at% oxygen. 3. A silver alloy reflective film, which is characterized in that it is made of a laminated film formed by laminating a silver alloy film and a metal oxide film contained in Table 1 or Table 2 of the scope of patent application. 4. A silver alloy sputtering target, which is characterized in that it is made of a silver alloy containing silver as the main component and containing Au and Sn. The Au content is 0.1 ~ 4.0at%, and the Sn content is 0.1 ~ 2.5at%. 5. A method for manufacturing a silver alloy thin film, characterized in that the silver alloy sputtering target described in claim 4 is used as a sputtering target, and Ar gas is used as a sputtering gas, such as oxygen, such as 02, H2O, or h2 + 02. At least one gas is selected from the gas to perform sputter plating to produce silver as a main component, and the AU content is 0.1 to 4.0 <%, and the 811 content is 0.1 to 2.5 & 1 ° / (), Silver alloy thin film with an oxygen content of 0.1 to 3. (^ 1%. 6. The method for manufacturing a silver alloy thin film as described in item 5 of the scope of patent application, wherein 'only supplied at the initial stage of film formation by sputtering. Oxygen-containing gas. 7. A method for manufacturing a silver alloy thin film having a laminated structure, characterized in that, in the manufacturing method described in item 5 of the scope of patent application, a metal oxide film as a base layer is laminated and formed Silver alloy thin film, but is sputtered with or without additional gas during sputtering to produce a silver alloy thin film. -19-