Method and system for post-treating dry-etched metal film

Abstract

A method for post-treating a dry-etched metal film is provided. The dry-etched metal film includes an unetched portion covered by a photoresist and an etched portion exposed from the photoresist and having thereon an etching by-product. According to the method, a stripping agent is used to remove the photoresist on the unetched portion, while reacting the stripping agent with the etching by-product to form a passivation layer on the exposed metal film. Then, a washing agent is used to remove the passivation layer after the photoresist is removed. A system for performing combined etching and stripping procedures of a metal film is also provided. The system comprises dry-etching chambers, stripping and cleaning chambers and a transportation device. In the stripping and cleaning chambers, the photoresist on the unetched portion is removed by a stripping agent and a passivation layer is formed on the etched portion by reacting the stripping agent.

What is claimed is:  
     
         1 . A method for post-treating a dry-etched metal film, said dry-etched metal film comprising an unetched portion covered by a photoresist and an etched portion exposed from said photoresist and having thereon an etching by-product, said method comprising steps of: 
 using a stripping agent to remove said photoresist on said unetched portion, while reacting said stripping agent with said etching by-product to form a passivation layer on said exposed metal film; and    using a washing agent to remove said passivation layer after said photoresist is removed.    
     
     
         2 . The method according to  claim 1  wherein said metal film is an aluminum-based film.  
     
     
         3 . The method according to  claim 2  wherein said aluminum-based film is made of a material selected from one of aluminum and aluminum alloy.  
     
     
         4 . The method according to  claim 2  wherein said etching by-product is aluminum chloride (AlCl x ).  
     
     
         5 . The method according to  claim 1  wherein said passivation layer is substantially non-reactive to water.  
     
     
         6 . The method according to  claim 1  wherein said stripping agent is monoethanolamine (MEA).  
     
     
         7 . The method according to  claim 6  wherein said washing agent is isopropyl alcohol (IPA), water or a combination thereof.  
     
     
         8 . The method according to  claim 1  being substantially performed immediately after said dry-etched metal film is formed.  
     
     
         9 . The method according to  claim 1  further comprising a primary treatment step before the step of said stripping step, wherein said primary treatment step is selected from a group consisting of carbon tetrafluoride/oxygen (CF 4 /O 2 ) plasma treatment, gaseous water/oxygen (H 2 O(g)/O 2 ) plasma treatment, hydrocarbonfluoride (C x H y F 2 ) deposition plasma treatment, ashing treatment and hot water rinse treatment.  
     
     
         10 . A method for dry etching a metal film, said method comprising steps of: 
 providing a substrate with a metal film thereon, said metal film having a first portion covered by a photoresist and a second portion uncovered by said photoresist;    using a dry etchant to etch off said second portion;    using a stripping agent to remove said photoresist on said first portion and simultaneously form a water-insoluble passivation layer on a third portion of said etched metal film exposed from said photoresist; and    using a washing agent to wash off said water-insoluble passivation layer after said photoresist is removed.    
     
     
         11 . The method according to  claim 10  wherein said metal film is made of one of aluminum and aluminum alloy.  
     
     
         12 . The method according to  claim 11  wherein said dry etchant includes one of chlorine (Cl 2 ) and boron chloride (BCl 3 ), which reacts with aluminum to form water-soluble aluminum chloride (AlCl x ) on said third portion of said metal film, and said stripping agent reacts with aluminum chloride (AlCl x ) to form said water-insoluble passivation layer on said thrid portion of said metal film.  
     
     
         13 . The method according to  claim 10  wherein said stripping agent is monoethanolamine (MEA), and said washing agent is isopropyl alcohol (IPA), water or a combination thereof.  
     
     
         14  The method according to  claim 10  wherein said stripping step is substantially performed immediately after said dry etch step.  
     
     
         15 . The method according to  claim 10  further comprising an initial treatment before the step of providing said stripping agent, and said initial treatment is selected from a group consisting of carbon tetrafluoride/oxgen (CF 4 /O 2 ) plasma treatment, gaseous water/oxygen (H 2 O(g)/O 2 ) plasma treatment, hydrocarbonfluoride (C x H y F 2 ) deposition plasma treatment, ashing treatment and hot water rinse treatment.  
     
     
         16 . A system for performing combined etching and stripping procedures of a metal film, said system comprising: 
 at least one dry-etching chambers where a substrate with a metal film is dry etched to form an unetched portion covered by a photoresist and an etched portion exposed from said photoresist;    at least one stripping and cleaning chambers where said photoresist on said unetched portion is removed by a stripping agent and a passivation layer is formed on said etched portion by reacting said stripping agent; and    a transportation device transferring said substrate between said at least one dry-etching chambers and said at least one stripping and cleaning chambers.    
     
     
         17 . The system according to  claim 16 , wherein each of said at least one stripping and cleaning chambers comprises a spin stripper.  
     
     
         18 . The system according to  claim 16  further comprising a load lock chamber and a transfer chamber between said at least one dry-etching chambers and said at least one stripping and cleaning chambers, and said transportation device transferring said substrate between said at least one dry-etching chambers and said at least one stripping and cleaning chambers through said load lock chamber and a transfer chamber.