Method and apparatus for processing substrate

Abstract

A substrate processing method can securely form a metal film by electroless plating on an exposed surface of a base metal, such as interconnects, with increased throughput and without the formation of voids in the base metal. The substrate processing method includes: cleaning a surface of a substrate having a base metal formed in the surface with a cleaning solution comprising an aqueous solution of a carboxyl group-containing organic acid or its salt and a surfactant as an additive; bringing the surface of the substrate after the cleaning into contact with a processing solution comprising a mixture of the cleaning solution and a solution containing a catalyst metal ion, thereby applying the catalyst to the surface of the substrate; and forming a metal film by electroless plating on the catalyst-applied surface of the substrate.

1 . A substrate processing method comprising: 
 preparing a substrate by forming interconnect recesses in a surface, and forming a film of an interconnect material on the surface while embedding the interconnect material in the interconnect recesses;    removing an extra interconnect material other than the interconnect material in the recesses by chemical-mechanical polishing, thereby forming interconnects composed of the interconnect material in the recesses;    bringing the surface of the substrate, immediately after the polishing, into contact with a cleaning solution to remove polishing residues and an oxide film formed in surfaces of interconnects;    bringing the surface of the substrate after the cleaning into contact with a catalyst processing solution to apply a catalyst to the surfaces of interconnects; and    cleaning the catalyst-applied substrate surface, followed by drying.    
   
   
       2 . The substrate processing method according to  claim 1 , wherein the dried substrate is stored in a storage container having a controlled internal atmosphere.  
   
   
       3 . The substrate processing method according to  claim 1 , wherein the cleaning of the catalyst-applied substrate surface is carried out by rinsing with pure water.  
   
   
       4 . The substrate processing method according to  claim 1 , wherein the cleaning of the catalyst-applied substrate is carried out by cleaning with a chemical solution containing a chelating agent, followed by rinsing with pure water.  
   
   
       5 . The substrate processing method according to  claim 2 , wherein the storage container is an openable and closable hermetic container capable of controlling at least one of the internal humidity, temperature, oxygen concentration, and floating contaminant.  
   
   
       6 . The substrate processing method according to  claim 1 , wherein the catalyst processing solution is a mixture of the cleaning solution and a solution containing a catalyst metal ion.  
   
   
       7 . A substrate processing method comprising: 
 carrying a substrate, in which a catalyst has been applied to the surface of embedded interconnects formed in a surface of the substrate, into an apparatus frame of an electroless plating apparatus; and    directly forming a protective film by electroless plating selectively on surfaces of interconnects of the substrate.    
   
   
       8 . The substrate processing method according to  claim 7 , wherein immediately before carrying the substrate into the apparatus frame of the electroless plating apparatus, the substrate is stored in a storage container having a controlled internal atmosphere.  
   
   
       9 . The substrate processing method according to  claim 7 , wherein the substrate after the formation of the protective film is subjected to post-processing, followed by drying.  
   
   
       10 . The substrate processing method according to  claim 9 , wherein the post-processing of the substrate is chemical cleaning or etching to selectively remove impurities remaining on a nonmetallic surface of the substrate.  
   
   
       11 . The substrate processing method according to  claim 9 , wherein the post-processing of the substrate is plasma processing to selectively remove or modify impurities remaining on a nonmetallic surface of the substrate.  
   
   
       12 . The substrate processing method according to  claim 7 , wherein at least one of a film thickness and a film property of the protective film is measured after drying and, based on comparison of the measured value with a target value, the processing conditions of electroless plating in the electroless plating apparatus are adjusted.  
   
   
       13 . A substrate processing method comprising: 
 preparing a substrate by forming interconnect recesses in a surface, and forming a film of an interconnect material on the surface while embedding the interconnect material in the interconnect recesses;    removing an extra interconnect material other than the interconnect material in the recesses by chemical-mechanical polishing, thereby forming interconnects composed of the interconnect material in the recesses;    bringing the surface of the substrate, immediately after the polishing, into contact with a cleaning solution to remove polishing residues and an oxide film formed in surfaces of interconnects;    bringing the surface of the substrate after the cleaning into contact with a catalyst processing solution to apply a catalyst to the surfaces of interconnects; and    cleaning the catalyst-applied substrate surface, followed by direct formation of a protective film by electroless plating on the surfaces of interconnects of the substrate.    
   
   
       14 . The substrate processing method according to  claim 13 , wherein the cleaning of the catalyst-applied substrate surface is carried out by rinsing with pure water.  
   
   
       15 . The substrate processing method according to  claim 13 , wherein the cleaning of the catalyst-applied substrate surface is carried out by cleaning with a chemical solution containing a chelating agent, followed by rinsing with pure water.  
   
   
       16 . The substrate processing method according to  claim 13 , wherein the substrate is dried immediately after the cleaning of the catalyst-applied substrate surface.  
   
   
       17 . The substrate processing method according to  claim 16 , wherein the dried substrate is stored in a storage container having a controlled internal atmosphere until just before the direct formation of the protective film by electroless plating on the surfaces of interconnects.