Abstract:
The present invention proposes a method for removing an oxide formed on the surface of a copper film used in the process of manufacturing a circuit for a semiconductor, an organic light-emitting diode, an LED, or a liquid crystal display without causing corrosion on a lower metal film. The composition including corrosive amine may remove a metal oxide depending on the content of additive ranging from 0.01 to 10% regardless of the content of ultrapure water. A polar solvent other than the corrosive amine may efficiently remove an oxide from the surface of the metal when the same contains water and 0.01 to 20% of the additive.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a national stage application under 35 U.S.C. §371 of International Application No. PCT/KR2013/006615, filed Jul. 24, 2013, which claims priority to Korean Application No. 1020120080440, filed Jul. 24, 2012, the disclosure of each of which are explicitly incorporated by reference herein in their entirety. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a composition for removing and preventing the formation of an oxide on the surface of a metal wire. More specifically, the present invention relates to a composition for removing an oxide on the surface of a metal wire formed in the process of manufacturing a circuit for a semiconductor, or a circuit for a liquid crystal display (LCD), a light-emitting diode (LED) or an organic light-emitting diode (OLED) display device, and preventing the formation of the oxide. 
     2. Description of Related Art 
     Metal wiring circuits used in semiconductor circuits or in circuits for liquid crystal display (LCD), light emitting diode (LED) or organic light emitting diode (OLED) display devices become more and more miniaturized in their structures as the circuits become integrated. 
     Meanwhile, metals such as Al, Ti, Cu, Ag and Au have been used as the materials of metal wire. Among these, Cu has been widely used over various fields due to its excellent electrical conductivity and relatively low costs. However, Cu is very readily oxidized even in the atmosphere, therefore, the surface of a wire using Cu becomes covered with an oxide as it passes through a unit process that progresses wiring. In other words, the surface of a wire using Cu becomes covered with an oxide as it passes through a heat treatment process capable of depositing a low dielectric material, an exposure process capable of determining the shape of a metal wire using a photosensitive material, an etching process capable of forming a metal wiring film after the exposure process, and a peeling-off process removing the photosensitive material remaining on the surface of the metal wiring film after the etching process. However, such an oxide lowers electrical conductivity of Cu itself, increases electrical resistance, and eventually, makes it difficult to obtain a fine low voltage circuit structure. Consequently, Cu has not been used as a metal used in circuits for OLED display devices so far. 
     Therefore, finer metal circuit wiring may be obtained when electrical conductivity of a metal wire itself can be maintained by removing an oxide on the surface of a metal wire formed while passing through such various processes. However, metal oxide film and metal film have very similar properties, and selectively removing the metal oxide has not been possible so for. 
     BRIEF SUMMARY OF THE INVENTION 
     Technical Problem 
     An object of the present invention is to provide a composition capable of selectively removing an oxide on the surface of a metal wire. 
     Another object of the present invention is to provide a composition capable of preventing the formation of an oxide on the surface of a metal wire. 
     Still another object of the present invention is to provide a composition capable of preventing corrosion on a lower metal film while being capable of removing an oxide on the surface of a metal wire and preventing the formation of the oxide. 
     Technical Solution 
     A composition for removing and preventing the formation of an oxide on the surface of a metal wire according to the present invention includes a compound represented by the following Chemical Formula 1 in 0.01 to 20% by weight; an organic solvent in 10 to 99.99% by weight; and water in 0 to 70% by weight: 
     
       
                 
         
             
             
         
      
     
     In Chemical Formula 1, X 1  is C or S, 
     X 2  is CR 1   2 , NR 2 , O or S, and herein, R 1  and R 2  are each independently hydrogen, C 1-12  alkyl, C 1-12  alkylthiol or C 1-12  alkoxy, C 6-12  awl, or hydroxy, and 
     X 3  and X 4  are each independently CR 3  or N, and herein, R 3  is each independently hydrogen, C 1-12  alkyl or C 1-12  alkylthiol, or hydroxy, and herein, when X 3  and X 4  are all CR 3  and R 3  is C 1-12  alkyl, carbons at the end of R 3 , a substituent, may bond to each other to form a saturated or unsaturated ring. 
     In one embodiment of the present invention, the compound represented by Chemical Formula 1 is selected from the group consisting of phenylmercaptotetrazole, mercaptobenzothiazole, mercaptobenzimidazole, mercaptobenzothiadiazole, mercaptobenzoxazole, mercaptomethyltetrazole, methylthiadiazolethiol, methoxymercaptobenzimidazole, cyclohexylmercaptoimidazole, mercaptoimidazole, mercaptomethylimidazole, mercaptoethylimidazole, mercaptopropylimidazole, mercaptoethyleneimidazole, mercaptopropyleneimidazole, cyclopentylmercaptoimidazole, cycloheptylimidazole, cyclooctylimidazole, mercapto(beta-4-pyridethyl)benzimidazole, mercaptonaph(2,3)thyimidazole, hydroxyoxidoaminomercapto-1H-imidazole, mercaptomethylnitroimidazole, and a mixture thereof. 
     In one embodiment of the present invention, the organic solvent is an amine-based solvent. 
     In one embodiment of the present invention, the amine-based solvent is selected from the group consisting of monoethanolamine, monoisopropylamine, diethanolamine, triethanolamine, N-methyldiethanolamine, diisopropylamine, aminopropanol, monomethylethanolamine, aminoethylethanolamine, dimethylethanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine, N-aminoethylpiperazine, dimethylpiperazine, dimethylaminopropylamine, aminopropylmorpholine, methoxypropylamine, pentamethyldiethyleneamine, ethylenediamine, diethylenetriamine, triethylenetetraamine, tetraethylenepentaamine, and a mixture thereof. 
     In another embodiment of the present invention, the organic solvent is selected from the group consisting of alcohol-based solvents, amide-based solvents, glycol-based solvents, glycol ether-based solvents and a mixture thereof, and the water is included in 1 to 70% by weight. 
     In one embodiment of the present invention, the organic solvent is selected from the group consisting of ethylene glycol monomethyl ether, propylene glycol propyl ether, diethylene glycol monomethyl ether, ethylene glycol monobutyl ether, triethylene glycol butyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tripropylene glycol methyl ether, ethylene glycol methyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether acetate, 3-methoxy-1-butanol, dipropylene glycol monomethyl ether, propylene glycol dimethyl ether, 3-methoxy-1-propanol, 2-ethoxy ethyl acetate, n-methyl-2-pyrrolidone, ethylene carbitol, propylene carbitol, gammabutyl lactone, dimethyl sulfoxide, sulfolane, dimethylformamide, tetrahydrofurfuryl alcohol, propargyl alcohol, triethylene glycol monoethyl ether, polyethylene glycol monoethyl ether, propylene glycol monomethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monoisobutyl ether, diethylene glycol monophenyl ether, and a mixture thereof. 
     In one embodiment of the present invention, the metal is Cu. 
     Advantageous Effects 
     A composition according to the present invention prevents the corrosion of a lower metal film while selectively removing an oxide on the surface of a metal wire, and preventing the formation of the oxide on the surface of the metal wire. Therefore, it is capable of maintaining electrical conductivity of a metal wire itself and is capable of finer metal circuit wiring. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a photograph of a glass image immediately after depositing Cu. 
         FIG. 2  is a photograph of an image after artificially forming an oxide on the surface of a metal by holding up the glass of  FIG. 1  for 20 minutes on a heating plate at 170° C. 
         FIG. 3  is a photograph of an image of the glass of  FIG. 2  being sunk in a beaker containing a composition according to the present invention. 
         FIG. 4  is a photograph taken after taking out the glass of  FIG. 3 , which shows a result in which water drops favorably spread in parts that oxides are formed in large quantities, and shows a result in which water drops do not spread well in regions that oxides are removed. 
         FIG. 5  is a result of XPS analysis carried out on the glass of  FIG. 1 . 
         FIG. 6  is a result of XPS analysis carried out on the glass of  FIG. 2 . 
         FIG. 7  is a result of XPS analysis carried out after removing a metal oxide using a composition according to the present invention. 
         FIG. 8  illustrates a mechanism of removing an oxide on the surface of a metal wire. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A composition for removing and preventing the formation of an oxide on the surface of a metal wire according to the present invention includes a compound represented by the following Chemical Formula 1 in 0.01 to 20% by weight; an organic solvent in 10 to 99.99% by weight; and water in 0 to 70% by weight: 
     
       
                 
         
             
             
         
      
     
     In Chemical Formula 1, X 1  is C or S, 
     X 2  is CR 1   2 , NR 2 , O or S, and herein, R 1  and R 2  are each independently hydrogen, C 1-12  alkyl, C 1-12  alkylthiol or C 1-12  alkoxy, C 6-12  aryl, or hydroxy, and 
     X 3  and X 4  are each independently CR 3  or N, and herein, R 3  is each independently hydrogen, C 1-12  alkyl or C 1-12  alkylthiol, or hydroxy, and herein, when X 3  and X 4  are all CR 3  and R 3  is C 1-12  alkyl, carbons at the end of R 3 , a substituent, may bond to each other to form a saturated or unsaturated ring. 
     In one embodiment of the present invention, the compound represented by Chemical Formula 1 is selected from the group consisting of phenylmercaptotetrazole, mercaptobenzothiazole, mercaptobenzimidazole, mercaptobenzothiadiazole, mercaptobenzoxazole, mercaptomethyltetrazole, methylthiadiazolethiol, methoxymercaptobenzimidazole, cyclohexylmercaptoimidazole, mercaptoimidazole, mercaptomethylimidazole, mercaptoethylimidazole, mercaptopropylimidazole, mercaptoethyleneimidazole, mercaptopropyleneimidazole, cyclopentylmercaptoimidazole, cycloheptylimidazole, cyclooctylimidazole, mercapto(beta-4-pyridethyl)benzimidazole mercaptonaph(2,3)thyimidazole, hydroxyoxidoaminomercapto-1H-imidazole mercaptomethylnitroimidazole, and a mixture thereof. 
     In one embodiment of the present invention, the organic solvent is an amine-based solvent. In this case, an oxide on the surface of a metal wire may be selectively removed whether or not water is included. 
     In one embodiment of the present invention, the amine-based solvent is selected from the group consisting of monoethanolamine, monoisopropylamine, diethanolamine, triethanolamine, N-methyldiethanolamine, diisopropylamine, aminopropanol, monomethylethanolamine, aminoethylethanolamine, dimethylethanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine, N-aminoethylpiperazine, dimethylpiperazine, dimethylaminopropylamine, aminopropylmorpholine, methoxypropylamine, pentamethyldiethyleneamine, ethylenediamine, diethylenetriamine, triethylenetetraamine, tetraethylenepentaamine, and a mixture thereof. 
     In another embodiment of the present invention, the organic solvent is selected from the group consisting of alcohol-based solvents, amide-based solvents, glycol-based solvents, glycol ether-based solvents and a mixture thereof, and the water is included in 1 to 70% by weight. In other words, when the organic solvent includes alcohol-based solvents, amide-based solvents, glycol-based solvents, glycol ether-based solvents and the like without including amine-based solvents, water needs to be included in order to selectively remove an oxide on the surface of a metal wire. 
     In one embodiment of the present invention, the organic solvent is selected from the group consisting of ethylene glycol monomethyl ether, propylene glycol propyl ether, diethylene glycol monomethyl ether, ethylene glycol monobutyl ether, triethylene glycol butyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tripropylene glycol methyl ether, ethylene glycol methyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether acetate, 3-methoxy-1-butanol, dipropylene glycol monomethyl ether, propylene glycol dimethyl ether, 3-methoxy-propanol, 2-ethoxyethyl acetate, n-methyl-2-pyrrolidone, ethylene carbitol, propylene carbitol, gamma butyl lactone, dimethyl sulfoxide, sulforan, dimethylformamide, tetrahydrofurfuryl alcohol, propargyl alcohol, triethylene glycol monoethyl ether, polyethylene glycol monoethyl ether, propylene glycol monomethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monoisobutyl ether, diethylene glycol monophenyl ether, and a mixture thereof. 
     In one embodiment of the present invention, the metal is Cu. 
     In the present invention, a mechanism of removing an oxide on the surface of a metal wire is provided in  FIG. 8 . 
       FIG. 8 , Step L: When water is present, a sulfur atom (S) of a mercapto group (SH) bonding to the compound represented by Chemical Formula 1 is coordinate bonded to a metal (Cu), and a heteroatom (N, O or S) (X) forming the compound represented by Chemical Formula 1 and having unshared electron pairs is coordinate bonded to an oxygen atom (O) of a metal oxide with a hydrogen atom bonding thereto or a hydrogen ion (H + ) in the composition as a medium. 
       FIG. 8 , Step  2 : Next, the hydrogen ion (H + ) and the oxygen atom (O) of the metal oxide bonding thereto bond to a hydrogen ion (H) present in the composition, and enter into the composition in the form of water (H 2 O). 
     When the oxygen atom is removed from the metal oxide and when a pure metal surface is revealed, further formation of a metal oxide is prevented by the compound represented by Chemical Formula 1 coordinate bonded to the metal through the mercapto group. 
     In addition, the compound represented by Chemical Formula 1 coordinate bonded to the metal through the mercapto group prevents corrosion by protecting the surface of the metal wire. 
     Meanwhile, when water is not present, the oxygen atom of the metal oxide is removed from the surface by an amine groups or a hydroxyl group in the composition. 
     Finally, the mercapto group (SH) is very weakly bonded to the surface of the metal, and is readily cut by hydrogen bonding of water in an ultrapure water cleaning process afterward and is removed from the surface of the metal. 
     Hereinafter, the present invention will be described in more detail with reference to examples. However, the following example is for illustrative purposes only, and the scope of the present invention is not limited to the following example. 
     Example 
     An oxide was artificially formed on the surface of a metal film by holding up a glass deposited with a metal for 20 minutes on a heating plate at 170° C., and then the metal film in which the oxide was formed was sunk in a composition according to the present invention for 20 minutes while maintaining a temperature at 40° C., and then the metal film was taken out. Removal of the oxide from the metal surface and corrosion of the metal was observed with the naked eye. During a test, a Cu metal film was used as an upper metal film of the glass. 
     Table 1 is a case using an amine-based solvent as the organic solvent, and Table 2 is a case using a non-amine-based solvent as the organic solvent. The content unit of the constituents listed in the following Table 1 and Table 2 is a % by weight. The test results are evaluated using the following criteria, and the results are shown in Table 1 and Table 2. 
     Removal of Oxide 
     {circle around (∘)}: The metal oxide was removed within 2 minutes 
     Δ: The metal oxide was removed after 2 minutes 
     X: The metal oxide was not removed 
     Degree of Metal Corrosion 
     {circle around (∘)}: Same condition as a control group substrate 
     O: Film thickness was the same compared to a control group substrate, minor corrosion occurred on the surface 
     Δ: Film thickness was a little reduced compared to a control group substrate, and corrosion occurred on the surface 
     X: Film thickness was reduced by ½ or greater compared to a control group substrate due to corrosion 
     
       
         
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                   
                   
                   
                   
                   
                   
                   
                 Degree of 
               
               
                 Component 
                   
                 Component 
                   
                   
                   
                 Oxide 
                 Metal 
               
               
                 1 
                 Content 
                 2 
                 Content 
                 Water  
                 Content 
                 Removal 
                 Corrosion 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 MI 
                 1 
                 MEA 
                 50 
                 Included 
                 49 
                 ⊚ 
                 ⊚ 
               
               
                 MBO 
                 1 
                 MIPA 
                 99 
                 Not 
                 0 
                 ⊚ 
                 ⊚ 
               
               
                   
                   
                   
                   
                 Included 
                   
                   
                   
               
               
                 MBTD 
                 1 
                 DEA 
                 50 
                 Included 
                 49 
                 ⊚ 
                 ⊚ 
               
               
                 MI 
                 1 
                 TEA 
                 99 
                 Not 
                 0 
                 ⊚ 
                 ⊚ 
               
               
                   
                   
                   
                   
                 Included 
                   
                   
                   
               
               
                 MBO 
                 1 
                 MDEA 
                 50 
                 Included 
                 49 
                 ⊚ 
                 ⊚ 
               
               
                 MBTD 
                 1 
                 DIPA 
                 99 
                 Not 
                 0 
                 ⊚ 
                 ⊚ 
               
               
                   
                   
                   
                   
                 Included 
                   
                   
                   
               
               
                 MI 
                 1 
                 AMP 
                 50 
                 Included 
                 49 
                 ⊚ 
                 ⊚ 
               
               
                 MBO 
                 1 
                 MMEA 
                 99 
                 Not 
                 0 
                 ⊚ 
                 ⊚ 
               
               
                   
                   
                   
                   
                 Included 
                   
                   
                   
               
               
                 MBTD 
                 1 
                 AEEA 
                 50 
                 Included 
                 49 
                 ⊚ 
                 ⊚ 
               
               
                 MI 
                 1 
                 DMEA 
                 99 
                 Not 
                 0 
                 ⊚ 
                 ⊚ 
               
               
                   
                   
                   
                   
                 Included 
                   
                   
                   
               
               
                 MBO 
                 1 
                 MOR 
                 50 
                 Included 
                 49 
                 ⊚ 
                 ⊚ 
               
               
                 MBTD 
                 1 
                 NMM 
                 99 
                 Not 
                 0 
                 ⊚ 
                 ⊚ 
               
               
                   
                   
                   
                   
                 Included 
                   
                   
                   
               
               
                 MI 
                 1 
                 NEM 
                 50 
                 Included 
                 49 
                 ⊚ 
                 ⊚ 
               
               
                 MBTD 
                 1 
                 AEP 
                 99 
                 Not 
                 0 
                 ⊚ 
                 ⊚ 
               
               
                   
                   
                   
                   
                 Included 
                   
                   
                   
               
               
                 MI 
                 1 
                 DMP 
                 50 
                 Included 
                 49 
                 ⊚ 
                 ⊚ 
               
               
                 MBO 
                 1 
                 DMAPA 
                 99 
                 Not 
                 0 
                 ⊚ 
                 ⊚ 
               
               
                   
                   
                   
                   
                 Included 
                   
                   
                   
               
               
                 MBTD 
                 1 
                 MOPA 
                 50 
                 Included 
                 49 
                 ⊚ 
                 ⊚ 
               
               
                 MI 
                 1 
                 APM 
                 99 
                 Not 
                 0 
                 ⊚ 
                 ⊚ 
               
               
                   
                   
                   
                   
                 Included 
                   
                   
                   
               
               
                 MBO 
                 1 
                 DMCHA 
                 50 
                 Included 
                 49 
                 ⊚ 
                 ⊚ 
               
               
                 MBTD 
                 1 
                 PMDETA 
                 99 
                 Not 
                 0 
                 ⊚ 
                 ⊚ 
               
               
                   
                   
                   
                   
                 Included 
                   
                   
                   
               
               
                 MI 
                 1 
                 EDA 
                 50 
                 Included 
                 49 
                 ⊚ 
                 ⊚ 
               
               
                 MBO 
                 1 
                 DETA 
                 99 
                 Not 
                 0 
                 ⊚ 
                 ⊚ 
               
               
                   
                   
                   
                   
                 Included 
                   
                   
                   
               
               
                 MBTD 
                 1 
                 TETA 
                 50 
                 Included 
                 49 
                 ⊚ 
                 ⊚ 
               
               
                 MI 
                 1 
                 TEPA 
                 99 
                 Not 
                 0 
                 ⊚ 
                 ⊚ 
               
               
                   
                   
                   
                   
                 Included 
               
               
                   
               
               
                 MI: mercaptoimidazole 
               
               
                 MBO: mercaptobenzoxazole 
               
               
                 MBTD: mercaptobenzthiadiazole 
               
               
                 MEA: monoethanolamine 
               
               
                 MIPA: monoisopropylamine 
               
               
                 DEA: diethanolamine 
               
               
                 TEA: triethanolamine 
               
               
                 MDEA: n-methyldiethanolamine 
               
               
                 DIPA: diisopropylamine 
               
               
                 AMP: aminopropanol 
               
               
                 MMEA: monomethylethanolamine 
               
               
                 AEEA: aminoethylethanolamine 
               
               
                 DMEA: dimethylethanolamine 
               
               
                 MOR: morpholine 
               
               
                 NMM: N-methylmorpholine 
               
               
                 NEM: N-ethylmorpholine 
               
               
                 AEP: N-aminoethylpiperazine 
               
               
                 DMP: dimethylpiperazine 
               
               
                 DMAPA: dimethylaminopropylamine 
               
               
                 MOPA: dimethylpiperazine 
               
               
                 APM: aminopropylmotpholine 
               
               
                 DMCHA: dimethylaminopropylamine 
               
               
                 MOPA: methoxypropylamine 
               
               
                 APM: aminopropylmotpholine 
               
               
                 PMDETA: pentamethyldiethyleneamine 
               
               
                 EDA: ethylenediamine 
               
               
                 DETA: diethylenetriamine 
               
               
                 TETA: triethylenetetraamine 
               
               
                 TEPA: tetraethylenepentaamine 
               
             
          
         
       
     
     
       
         
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                   
                   
                   
                   
                   
                   
                   
                 Degree of 
               
               
                 Component  
                   
                 Component  
                   
                   
                   
                 Oxide 
                 Metal 
               
               
                 1 
                 Content 
                 2 
                 Content 
                 Water 
                 Content 
                 Removal 
                 Corrosion 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 MI 
                 1 
                 NMP 
                 50 
                 Included 
                 49 
                 ⊚ 
                 ⊚ 
               
               
                 MBO 
                 1 
                 EC 
                 49 
                 Included 
                 50 
                 ⊚ 
                 ⊚ 
               
               
                 MBTD 
                 1 
                 PC 
                 50 
                 Included 
                 49 
                 ⊚ 
                 ⊚ 
               
               
                 MI 
                 1 
                 GBL 
                 49 
                 Included 
                 50 
                 ⊚ 
                 ⊚ 
               
               
                 MBO 
                 1 
                 DMSO 
                 50 
                 Included 
                 49 
                 ⊚ 
                 ⊚ 
               
               
                 MBTD 
                 1 
                 Sulforan 
                 49 
                 Included 
                 50 
                 ⊚ 
                 ⊚ 
               
               
                 MI 
                 1 
                 DMF 
                 50 
                 Included 
                 49 
                 ⊚ 
                 ⊚ 
               
               
                 MBO 
                 1 
                 THFA 
                 49 
                 Included 
                 50 
                 ⊚ 
                 ⊚ 
               
               
                 MBTD 
                 1 
                 PA 
                 50 
                 Included 
                 49 
                 ⊚ 
                 ⊚ 
               
               
                 MI 
                 1 
                 MG 
                 49 
                 Included 
                 50 
                 ⊚ 
                 ⊚ 
               
               
                 MBO 
                 1 
                 MDG 
                 50 
                 Included 
                 49 
                 ⊚ 
                 ⊚ 
               
               
                 MBTD 
                 1 
                 EG 
                 49 
                 Included 
                 50 
                 ⊚ 
                 ⊚ 
               
               
                 MI 
                 1 
                 EDG 
                 50 
                 Included 
                 49 
                 ⊚ 
                 ⊚ 
               
               
                 MBO 
                 1 
                 ETG 
                 49 
                 Included 
                 50 
                 ⊚ 
                 ⊚ 
               
               
                 MBTD 
                 1 
                 EPG 
                 50 
                 Included 
                 49 
                 ⊚ 
                 ⊚ 
               
               
                 MI 
                 1 
                 BDG 
                 49 
                 Included 
                 50 
                 ⊚ 
                 ⊚ 
               
               
                 MBO 
                 1 
                 MFG 
                 50 
                 Included 
                 49 
                 ⊚ 
                 ⊚ 
               
               
                 MBTD 
                 1 
                 BFG 
                 49 
                 Included 
                 50 
                 ⊚ 
                 ⊚ 
               
               
                 MI 
                 1 
                 iPG 
                 50 
                 Included 
                 49 
                 ⊚ 
                 ⊚ 
               
               
                 MBO 
                 1 
                 iBG 
                 49 
                 Included 
                 50 
                 ⊚ 
                 ⊚ 
               
               
                 MBTD 
                 1 
                 PC 
                 99 
                 Not 
                 0 
                 X 
                 ⊚ 
               
               
                   
                   
                   
                   
                 Included 
                   
                   
                   
               
               
                 MI 
                 1 
                 GBL 
                 99 
                 Not 
                 0 
                 X 
                 ⊚ 
               
               
                   
                   
                   
                   
                 Included 
                   
                   
                   
               
               
                 MBO 
                   
                 DMSO 
                 99 
                 Not 
                 0 
                 X 
                 ⊚ 
               
               
                   
                   
                   
                   
                 Included 
                   
                   
                   
               
               
                 MBTD 
                 1 
                 Sulforan  
                 99 
                 Not 
                 0 
                 X 
                 ⊚ 
               
               
                   
                   
                   
                   
                 Included 
                   
                   
                   
               
               
                 MI 
                 1 
                 DMF 
                 99 
                 Not 
                 0 
                 X 
                 ⊚ 
               
               
                   
                   
                   
                   
                 Included 
                   
                   
                   
               
               
                 MBTD 
                 1 
                 PA 
                 99 
                 Not 
                 0 
                 X 
                 ⊚ 
               
               
                   
                   
                   
                   
                 Included 
                   
                   
                   
               
               
                   
               
               
                 NMP: n-methyl-2-pyrrolidone 
               
               
                 EC: ethylene carbitol 
               
               
                 PC: propylene carbitol 
               
               
                 GBL: gamma butyl lactone 
               
               
                 DMSO: dimethyl sulfoxide 
               
               
                 Sulfolane: sulfolane 
               
               
                 DMF: dimethylformamide 
               
               
                 THFA: tetrahydrofurfuryl alcohol 
               
               
                 PA: propargyl alcohol 
               
               
                 MG: ethylene glycol monomethyl ether 
               
               
                 MDG: diethylene glycol monomethyl ether 
               
               
                 EG: ethylene glycol monoethyl ether 
               
               
                 EDG: diethylene glycol monoethyl ether 
               
               
                 ETG: triethylene glycol monoethyl ether 
               
               
                 EPG: polyethylene glycol monoethyl ether 
               
               
                 BDG: diethylene glycol monobutyl ether 
               
               
                 MFG: propylene glycol monomethyl ether 
               
               
                 iPG: ethylene glycol monoisopropyl ether 
               
               
                 iBG: ethylene glycol monoisobutyl ether 
               
               
                 BFG: diethylene glycol monophenyl ether 
               
               
                 PGPE: propylene glycol propyl ether 
               
               
                 EGMEA: ethylene glycol monobutyl ether acetate 
               
             
          
         
       
     
     While the present invention has been described with reference to exemplary embodiments, it will be apparent to those skilled in the art that various modifications may be made without departing from the scope of the present invention, and constituents of the present invention may be substituted with equivalents. In addition, specific conditions and materials may be employed in the instruction of the present invention by performing various modifications without departing from the essential scope of the present invention. Accordingly, the present invention is not limited to the disclosed specific embodiments as a best mode planned to implement the present invention, and the present invention shall be interpreted to include all embodiments that belong to the appended claims.