TWI223661B - Etchant formulation for ITO film - Google Patents

Abstract

Disclosed is the etchant composition for the etching of the transparent conductive ITO film's pattern in manufacturing process of the thin-film-transistor liquid-crystal-display. The disclosed composition comprises 0.1 to 20 wt% MHSO4 aqueous solution, in which M=K, Na, or NH4. This invention relates to the adjustment of characteristics regarding etching speed and etched patterns by adjusting the concentration of MHSO4 and the addition of at least one of the additives chosen among KMnO4, H2O2, H2SO4, MHSO5 (M=K, Na, or NH4), HNO3, HClO4, NaClO4, M2S2O8 (M=K, Na, or NH4), KClO4, HIO4, and/or KIO4, in which the concentration for the additive(s) is 0.1 to 30 wt%. This invention relates to the removal of representative etching problems of residue resulting phenomenon, i.e. etching phenomenon of cell pattern in addition to the ITO film derived from the aluminum or aluminum/niobium alloy or the molybdenum or molybdenum/wolfram alloy, in order to increase the yield of the process.

Description

1223661 V. Description of the invention (l) [Detailed description of the invention] 发明 的 属 技术 # $ This invention is about showing dryness on a flat panel. Hiroshi Soda dipped in the composition of the etching solution of the transparent conductive film of emulsion tin (hereinafter referred to as ττη film) used by Nagasaki, Naji Temple, etc. Known as ITO, the conventionally known transparent conductive film is widely used in thin-film electro-crystal liquid crystal display devices, plasma display panel display devices, and electroluminescence display devices. An etching step of forming a transparent conductive film on a display device to form a desired fine pattern is necessary. As for the transparent conductive film used at this time, the IT0 film is mainly used.

The use of the aforementioned I TO film is to form an ITO film on a substrate such as glass, and then apply a photoresist as a mask to the ITO film, and then etch the ITO film. As for the existing ITO film, the etching solution is hydrochloric acid. , Nitric acid mixed aqueous solution (aqua regia system), hydrochloric acid, acetic acid mixed aqueous solution, gasified iron aqueous solution, ocular acid aqueous solution, phosphoric acid aqueous solution, oxalic acid aqueous solution, etc. However, the conventional etching solution for the film for Too contains the following: question. The first point is a mixed aqueous solution of hydrochloric acid and nitric acid and a mixed solution of hydrochloric acid and acetic acid.

Page 61223661 V. Description of the invention (2) 'I — · Each liquid is fast and son-in-law, but the time-dependent change of the remaining liquid appears =, the corrosion of the device caused by hydrochloric acid, and the use of Disadvantages of aluminum or aluminum, niobium alloy etching used as the gate electrode in the thin film transistor manufacturing step. The second point is that the ferric chloride aqueous solution has a fast and stable etching speed, but a relatively large amount of corrosion, and has the disadvantage of causing iron pollution. The third point is that the m-acid aqueous solution has a relatively small amount of side etching and has good etching characteristics, but has the disadvantage that the etching solution changes greatly with time. The fourth point is that the phosphoric acid aqueous solution has the disadvantage of using aluminum, aluminum, or niobium alloy as a gate electrode for etching. The fifth point is that the oxalic acid aqueous solution has stable etching characteristics, and the change of the etching solution does not cause ′. Therefore, although it is good, it has the disadvantage of easily slagging during etching. Free .. Ming _ The misunderstanding to be solved The present invention provides hydrochloric acid, nitric acid mixed aqueous solution [aqueous water system], hydrochloric acid, acetic acid mixed aqueous solution, vaporized iron aqueous solution, aqueous acid solution, etc. Phosphorus, phosphoric acid and oxalic acid aqueous solutions occur with time, change over time, and the phenomenon of generation of crumbling, engraving phenomenon of other films other than ITO film such as aluminum, niobium alloy, etc.

Page 7 1223661 V. Description of the invention (3) Disadvantages The composition of the etching solution for ITO film of the transparent conductive film, as for the main reactant of the film etching solution for Iτο, is MHS04 (M = K or Na, NH4) and The shortcomings of additives and water can completely remove the conventional etching solution for IT0 film. In particular, the main problem of forming conventional I TO etchant by removing

Residues during dot etching and other thin film etching phenomena other than IT0 films such as aluminum or aluminum, niobium alloys, molybdenum or molybdenum, crane alloys, etc., cause the etching of the I TO film etching step The reduction of the defective rate can improve the process yield. Feng Duan BB Road, which was replaced by MAA, is an invention that contains 171 ^ 1 ^ 0 of a display device for a flat panel display. Γ1Τ0 film is suitable for pattern etching in the pattern etching. The etching solution: Shifanshizhi Various characteristics are good and no residual molybdenum is generated in the remaining time. Aluminium or aluminum, niobium alloy bath solution, and town alloy are used as the electrode material. Engraving speed = m4) is the main component of the main component of the etching liquid, the degree of indifference or additional additives to improve the 1223661 V. Description of the invention (4) To add and use the additives used at this time, KMn〇4, H202, H2S〇4, M2S2 08 (M = K or Na, NH4), MHS〇5 (M = 1 ^ Na, NH4), HN〇3, HC104,

One or two or more of NaClO4, HI04, and KI04 can be used simultaneously, and the appropriate addition amount is 0.1 to 30% by weight. The etching mechanism of the I TO etchant of the present invention is as follows. IT0 is made of a mixture of iri203 and sn02, and it is formed by the reaction of MHS〇4 (M = K or Y2) as the main component of each oxide and ιτο etching solution. If you try to react with KHSO4 When the reaction equation is expressed, it is represented as follows.

In2 03 + 6KHS04 ^ In2 (S04) 3 + 3K2S04 + 3H20 Sn02 + 4KHS04 ^ Sn (S04) 2 + 2K2S04 + 2H20 In order to obtain additional additions, the various required characteristics adopted for the pattern's remaining time are inscribed speed and money The loss of prof i 1 e and CD and the uniformity of the last name are added.

The I TO etching solution of the present invention uses MHS04 (M = K or Na, NH4) of 0.1% of the main reactant, in which 0 ·; [~ 30% by weight of the agent, and the remainder is composed of water. Add to

1223661 V. Description of the invention (5) Application form of the invention The following describes embodiments of the present invention. fExample 1 In 0.1% by weight of iKHS04, 10% by weight of 03 and 0.5% by weight of H2 02 and water were added to produce an etching solution. The I TO film substrate (IT 0 film thickness 50 0A) that has been patterned with photoresist using this etchant is coated and etched at 40 ° C for 10 minutes, and then washed with ultrapure water for about 1 minute ' And dried with nitrogen. After the etching was finished in this way, the substrate surface was observed with an electron microscope. No residue was found on the substrate surface, and the surname phenomenon was also engraved on the aluminum, sharp film, and molybdenum film. 'It can be confirmed that the IT 0 film system has been well-prepared. Last name carved. Example 2 25% by weight was added to 2.5% by weight of 2KHS04. HN03 and 1.5% by weight of H2 02 and water to make an etching solution. The TO film substrate (IT0 film thickness 200A) that has been patterned with photoresist using this etching solution is coated and etched at 40 ° C for 5 minutes, then washed with ultrapure water for about 1 minute, and dried with nitrogen. .

Page 10 1223661 V. Description of the invention (6) After the end of the last name engraving, the result of observing the surface of the substrate with an electron microscope was not found on the substrate surface, and there were no residues, and there was no etching on Shao, sharp film and Gu film. It can be confirmed that the I το film is well carved. Paste Example 3 25% by weight of Dragon 03 and 1.5% by weight of H2O2 and water were added to 5% by weight of iKHS04 to produce an etching solution.

The IT0 film substrate (ITO film thickness 2000A) which has been patterned with photoresist using this etching solution is coated and etched at 40 ° C for 5 minutes, then washed with ultrapure water for about 1 minute, and dried with nitrogen. . After the silver engraving was finished in this way, the results of observing the surface of the substrate with an electron microscope showed no residue on the surface of the substrate. There was no etching on Yu Ming, sharp film, and Gu film. It can be confirmed that T0 film was well etched. Example 4 In 20% by weight of iKHS04, 15% by weight of ην03 and 1.0% by weight of Η2 02 and water were added to produce an etching solution.

An ITO film substrate (thickness of ITO film with a thickness of 2000A) which has been patterned with a photoresist using this last solution is coated and etched for 5 minutes at 40, and then washed with ultrapure water for about 1 minute, and Dry with nitrogen. 1223661

After the etching was finished in this way, the results of the substrate were observed with an electron microscope, and no residue was found on the surface of the substrate. There was no etching phenomenon on the film. It was confirmed that the ITO film had a good after-treatment. / 、 The effect of the invention

The etching solution for the ITO film of the present invention is suitable for pattern etching of the I TO film of a transparent conductive film suitable for a display device for a flat-panel display including a thin-film transistor liquid crystal display device. The difference is that it does not cause the phenomenon of residues during etching or the phenomenon of etching of aluminum or aluminum, niobium alloys and other thin films other than ITO films of molybdenum or indium and tungsten alloys, which can lead to savings in manufacturing cost and process yield. Improved effect.

Page 12 1223661

Page 13

Claims (1)

1223661 Amendment / Love. 六. Application for Patent Scope 1. An etching solution composition of transparent conductive film, which is characterized in that the transparent conductive film I TO film of a display device for a flat panel display containing a thin film transistor-a liquid crystal display device is etched in a pattern The etching solution used at this time is composed of MHS04 (M = K or Na, NΗ 4) as the main reactant and additives and water. Among them, the main reactant MHS04 (M = K or Na, ΝΗ4) as the last name is 0. Bu 20% by weight. 2. For example, the etching solution composition of the transparent conductive film of the scope of application for the patent, where the additives are KMn04, H 20 2, H2S04, M2S 20 8 (M = K or Na, ΝΗ4), MHS〇5 (M = K Or Na, NH4), HN〇3, HC104, KC14, HI04, ΚΙΟ ^ can be used at the same time, the weight of the additive is (K 1 ~ 30% by weight 〇 Page 14