Method for manufacturing an LCD device

Abstract

A method for manufacturing a TFT panel of an LCD device includes the steps of wet etching a multilayer metallic structure including a high-melting-point metal film (HMPM) film, Al film and another HMPM film while using side etching technique by using a photoresist mask, hot-water washing the side walls of the Al film after the wet etching, and dry etching for configuring the channel region of a TFT in each pixel, and removing the photoresist mask. The presence of the photoresist mask and the protection film prevents corrosion of Al caused by plasma of the etching gas in the dry etching.

What is claimed is:  
     
         1 . A method for manufacturing a liquid crystal display (LCD) device comprising: 
 consecutively forming a semiconductor layer and a multilayer metallic film to overlie a substrate, said multilayer metallic film including a high-melting-point metal (HMPM) film and a first metallic film having a lower resistivity than said HMPM film;    forming a photoresist mask on said multilayer metallic film;    patterning said multilayer metallic film by using said photoresist mask to form a multilayer metallic pattern, said patterning including a side etching for retracting edges of said multilayer metallic pattern beyond edges of line patterns of said photoresist mask;    forming a protection film on exposed portions of said first metallic film;    dry-etching at least a portion of said semiconductor layer by using said photoresist mask as an etching mask; and    removing said photoresist mask.    
     
     
         2 . The method according to  claim 1 , wherein said patterning step includes wet etching, and said protection film forming step includes hot-water washing subsequent to said wet etching.  
     
     
         3 . The method according to  claim 1 , wherein said dry etching step uses fluorine-based gas.  
     
     
         4 . A method for manufacturing a liquid crystal display (LCD) device comprising: 
 consecutively forming a semiconductor layer and a multilayer metallic film to overlie a substrate, said multilayer metallic film including a high-melting-point metal (HMPM) film and a first metallic film having a lower resistivity than said HMPM film;    forming a photoresist mask on said multilayer metallic film;    patterning said multilayer metallic film by using said photoresist mask to form a multilayer metallic pattern, said patterning including a side etching for retracting edges of said multilayer metallic pattern beyond edges of line patterns of said photoresist mask;    removing said photoresist pattern;    forming a protection film on exposed portions of said first metallic film; and    dry-etching at least a portion of said semiconductor layer by using said photoresist mask as an etching mask.    
     
     
         5 . The method according to  claim 4 , wherein said photoresist mask removing step includes a wet peel-off step, and said protection film forming step includes hot-water washing subsequent to said wet peel-off step.  
     
     
         6 . The method according to  claim 4 , wherein said dry etching step uses fluorine-based gas.  
     
     
         7 . A method for manufacturing a liquid crystal display (LCD) device comprising: 
 consecutively forming a semiconductor layer and a multilayer metallic film to overlie a substrate, said multilayer metallic film including a high-melting-point metal (HMPM) film and a first metallic film having a lower resistivity than said HMPM film;    forming a photoresist mask on said multilayer metallic film;    patterning said multilayer metallic film by using said photoresist mask to form a multilayer metallic pattern;    dry-etching at least a portion of said semiconductor layer by using said photoresist mask and/or said multilayer metallic pattern as an etching mask; and    evacuating a chamber upon completion of said dry-etching step in said chamber to remove etching gas used in said dry-etching step from said substrate including said multilayer metallic pattern.    
     
     
         8 . The method according to  claim 7 , wherein said evacuating step is executed so that said substrate is apart from chamber electrodes.  
     
     
         9 . The method according to  claim 7 , wherein said evacuating step is executed for 120 seconds or more.  
     
     
         10 . The method according to  claim 7 , further comprising the step of plasma treating said multilayer metallic pattern by using O 2 , N 2 , H 2  or He gas.  
     
     
         11 . A method for manufacturing a liquid crystal display (LCD) device comprising: 
 consecutively forming a semiconductor layer and a multilayer metallic film to overlie a substrate, said multilayer metallic film including a high-melting-point metal (HMPM) film and a first metallic film having a lower resistivity than said HMPM film;    forming a photoresist mask on said multilayer metallic film;    patterning said multilayer metallic film by using said photoresist mask to form a multilayer metallic pattern;    dry-etching at least a portion of said semiconductor layer by using said photoresist mask as an etching mask; and    removing said photoresist mask by using a wet peel-off process and simultaneously washing said substrate including said multilayer metallic pattern within a time length of 10 minutes after completion of said dry-etching step.    
     
     
         12 . A method for manufacturing a liquid crystal display (LCD) device comprising: 
 consecutively forming a semiconductor layer and a multilayer metallic film to overlie a substrate, said multilayer metallic film including a high-melting-point metal (HMPM) film and a first metallic film having a lower resistivity than said HMPM film;    forming a photoresist mask on said multilayer metallic film;    patterning said multilayer metallic film by using said photoresist mask to form a multilayer metallic pattern;    removing said photoresist mask;    dry-etching at least a portion of said semiconductor layer by using said multilayer metallic pattern as an etching mask;    water-washing said substrate including said multilayer metallic pattern within a time length of 10 minutes after completion of said dry-etching step.