Method of preparing low resistance metal line, patterned metal line structure, and display device using the same

Abstract

Disclosed herein is a method of preparing a low resistance metal line, in which a wet plating technique is used instead of a vacuum film forming process in order to simplify the process and decrease the manufacturing cost. In addition, a self-assembled monolayer is formed that facilitates the increased adsorption density and strength of the metal catalyst resulting in the formation of a high-density metal catalyst layer, thereby obtaining a high-quality metal line. Also disclosed herein, are a patterned metal line structure, and a display device using the same.

1 . A method of preparing a low resistance metal line comprising:
 forming a mask pattern for a metal line on a substrate;   applying a self-assembled monolayer on the substrate;   forming a seed layer on the substrate comprising the self-assembled monolayer;   plating an assistant metal film on the seed layer;   removing the mask pattern and layers thereon by means of lift-off; and   plating a metal layer on the patterned assistant metal film.   
   
   
       2 . The method of  claim 1 , wherein the self-assembled monolayer comprises an organosilane compound. 
   
   
       3 . The method of  claim 2 , wherein the self-assembled monolayer comprises a material represented by Formula 1 below:
   Si(OR) 3-n (R) n X  [Formula 1]   wherein R is a C 1-12  alkyl group, an alkylene group, or a phenyl group;   X is AB, in which A is a C 1-12  alkyl group, an alkylene group, or a phenyl group, and B is an amino group, a cyano group, a mercapto group, a pyridine group, or a diphenylphosphine group; and   n is an integer from 0 to 3.   
   
   
       4 . The method of  claim 3 , wherein the self-assembled monolayer comprises a material selected from a material group represented by Formula 2 below: 
     
       
         
         
             
             
         
       
     
   
   
       5 . The method of  claim 1 , wherein forming the seed layer is conducted using immersing method, spin coating, vapor deposition, Langmuir Blodgett method, or combinations thereof. 
   
   
       6 . The method of  claim 1 , wherein the forming the seed layer is conducted through activation using a metal selected from gold, silver, copper, nickel, tin, iron, platinum, palladium, palladium alloy, palladium chloride, or a combination comprising at least one of the foregoing metals for activation. 
   
   
       7 . The method of  claim 1 , wherein plating the assistant metal film is conducted using a metal selected from nickel, tin, cobalt, or zinc, or a combination comprising at least one of the foregoing metals. 
   
   
       8 . The method of  claim 1 , wherein plating the metal layer is conducted using electroless plating or electroplating. 
   
   
       9 . The method of  claim 1 , wherein plating the metal layer is conducted using a metal selected from Ni, Cu, Ag, Au, or alloys thereof, or a combination comprising at least one of the foregoing metals. 
   
   
       10 . The method of  claim 1 , wherein plating the metal layer is conducted by immersing the substrate in an electroless copper plating solution comprising a copper salt, a completing agent, a reducing agent, and a pH control agent. 
   
   
       11 . The method of  claim 1  further comprising: forming a passivation layer on the metal layer. 
   
   
       12 . The method of  claim 11 , wherein forming the passivation layer is conducted using a material selected from nickel, molybdenum, a nickel alloy, and a molybdenum alloy. 
   
   
       13 . The method of  claim 1  further comprising: annealing the low resistance metal line obtained after forming the metal layer. 
   
   
       14 . The method of  claim 13 , wherein the annealing is conducted at about 40 to about 400° C. for about 15 to about 120 minutes in a nitrogen or argon gas atmosphere, or in a vacuum. 
   
   
       15 . A patterned metal line structure formed on a substrate, which comprises:
 a self-assembled monolayer,   a seed layer comprising a metal catalyst, and   an assistant metal film layer formed between a lower substrate and an upper metal layer.   
   
   
       16 . The metal line structure of  claim 15  which further comprises:
 the self-assembled monolayer applied on the substrate;   the seed layer comprising the metal catalyst formed on the self-assembled monolayer;   the assistant metal film layer formed on the seed layer; and   the metal layer formed on the assistant metal film layer.   
   
   
       17 . The metal line structure of  claim 15 , wherein the self-assembled monolayer comprises an organosilane compound. 
   
   
       18 . The metal line structure of  claim 17 , wherein the self-assembled monolayer comprises a material represented by Formula 1 below:
   Si(OR) 3-n (R) n X  [Formula 1]   wherein R is a C 1-12  alkyl group, an alkylene group, or a phenyl group;   X is AB, in which A is a C 1-12  alkyl group, an alkylene group, or a phenyl group, and B is an amino group, a cyano group, a mercapto group, a pyridine group, or a diphenylphosphine group; and   n is an integer from 0 to 3.   
   
   
       19 . The metal line structure of  claim 18 , wherein the self-assembled monolayer comprises a material selected from a material group represented by Formula 2 below: 
     
       
         
         
             
             
         
       
     
   
   
       20 . The metal line structure of  claim 15 , wherein the seed layer comprises a metal catalyst selected from gold, silver, copper, nickel, tin, iron, platinum, palladium, a palladium alloy, or palladium chloride, or a combination comprising at least one of the foregoing metals. 
   
   
       21 . The metal line structure of  claim 15 , wherein the assistant metal film comprises a metal selected from nickel, tin, cobalt, or zinc, or a combination comprising at least one of the foregoing metals. 
   
   
       22 . The metal line structure of  claim 15 , wherein the metal layer comprises a conductive material selected from Ni, Cu, Ag, Au, and or alloys thereof, or a combination of at least one of the foregoing conductive materials. 
   
   
       23 . The metal line structure of  claim 15  further comprising: a passivation layer formed on the metal layer. 
   
   
       24 . The metal line structure of  claim 23 , wherein the passivation layer comprises nickel, molybdenum, a nickel alloy, or a molybdenum alloy. 
   
   
       25 . A display device, comprising the patterned metal line structure of  claim 15 .