Substrate processing method and substrate processing apparatus

Abstract

There is provided a substrate processing method which is capable of lowering the initial cost and the running cost of an apparatus, does not require a wide installation space, does not degrade electrical characteristics such as an interconnect resistance and a leakage current, and is capable of efficiently forming a high-quality alloy film on the surface of a metal region. The substrate processing method including; preparing a substrate having a metal region on a surface thereof, performing a pre-plating treatment by bringing a pretreatment liquid into contact with the surface of the substrate to modify the entire surface thereof, removing the pretreatment liquid remaining on the surface of the substrate in a rinsing treatment, performing an electroless plating process on the surface of the substrate to selectively form an alloy film on the surface of the metal region, and post-cleaning the substrate after the electroless plating process and drying the substrate.

1 . A substrate processing method comprising: 
 preparing a substrate having a metal region on a surface thereof;    performing a pre-plating treatment by bringing a pretreatment liquid into contact with the surface of the substrate to modify the entire surface thereof;    removing the pretreatment liquid remaining on the surface of the substrate in a rinsing treatment;    performing an electroless plating process on the surface of the substrate to selectively form an alloy film on the surface of said metal region; and    post-cleaning the substrate after the electroless plating process and drying the substrate.    
     
     
         2 . A substrate processing method according to  claim 1 , wherein said metal region comprises an exposed surface of an embedded interconnect formed in an insulator.  
     
     
         3 . A substrate processing method according to  claim 1 , wherein said metal region comprises a metal film formed on the bottom and side surfaces of a recess for an embedded interconnect formed in the surface of an insulator.  
     
     
         4 . A substrate processing method according to  claim 1 , wherein said metal region comprises an exposed surface of a metal interconnect formed in the surface of an insulator.  
     
     
         5 . A substrate processing method according to  claim 1 , wherein said pre-plating treatment comprises a treatment of purifying the surface of the substrate and simultaneously imparting a catalyst to said metal region to activate the surface of the metal region.  
     
     
         6 . A substrate processing method according to  claim 1 , wherein said pre-plating treatment and said rinsing treatment are performed by ejecting a chemical solution or pure water from a nozzle toward the surface of the substrate which faces downwardly.  
     
     
         7 . A substrate processing method according to  claim 6 , wherein said pre-plating treatment and said rinsing treatment are performed while the substrate is being rotated.  
     
     
         8 . A substrate processing method according to  claim 6 , wherein a nozzle used in said pre-plating treatment and a nozzle or nozzles used in said rinsing treatment are connected to respective different flow path systems.  
     
     
         9 . A substrate processing method according to  claim 1 , wherein said pre-plating treatment is performed by immersing the substrate in the pretreatment liquid.  
     
     
         10 . A substrate processing method according to  claim 1 , wherein the substrate is rotated at a higher speed after said pre-plating treatment is completed.  
     
     
         11 . A substrate processing method according to  claim 5 , wherein said pre-plating treatment is performed using the pretreatment liquid which is prepared by mixing at least together catalytic metal ions and an acid having a function to purify the surface of the substrate.  
     
     
         12 . A substrate processing method according to  claim 1 , wherein said rinsing treatment is performed by cleaning the surface of the substrate with pure water or pure water having a reducing capability increased by electrolysis or dissolving a hydrogen gas.  
     
     
         13 . A substrate processing method according to  claim 1 , wherein said rinsing treatment is performed by cleaning the surface of the substrate with an aqueous liquid prepared by mixing one component or some components of an electroless plating solution.  
     
     
         14 . A substrate processing method according to  claim 1 , wherein said pre-plating treatment and said rinsing treatment are performed in an atmosphere having less oxygen than the atmosphere.  
     
     
         15 . A substrate processing method according to  claim 1 , wherein said electroless plating process is performed in an atmosphere having less oxygen than the atmosphere.  
     
     
         16 . A substrate processing method according to  claim 1 , wherein at least one of a film thickness and a film property of said alloy film is measured after the substrate is post-cleaned and dried.  
     
     
         17 . A substrate processing method according to  claim 1 , wherein the compositions and component concentrations of said pretreatment liquid and a rinsing liquid therefore, and the temperature of said pretreatment liquid are kept in predetermined ranges.  
     
     
         18 . A substrate processing method according to  claim 1 , wherein the concentration of an impurity mixed in said pretreatment liquid in said pre-plating treatment is measured, and the impurity is removed when the impurity reaches a predetermined concentration.  
     
     
         19 . A substrate processing method according to  claim 1 , wherein said electroless plating process is performed by keeping the temperature, composition, and component concentrations of a plating solution in predetermined ranges, and controlling a plating process time with respect to a predetermined film thickness.  
     
     
         20 . A substrate processing apparatus comprising: 
 a pretreatment unit for performing a pre-plating treatment by bringing a surface of a substrate having a metal region into contact with a pretreatment liquid to modify the entire surface of the substrate, and a rinsing treatment for rinsing the pretreatment liquid remaining on the surface of the substrate after the pre-plating treatment;    an electroless plating unit for performing an electroless plating process on the surface of the substrate after the pre-plating treatment to selectively form an alloy film on the surface of said metal region; and    a post-treatment unit for post-cleaning the substrate after the electroless plating process and drying the substrate.    
     
     
         21 . A substrate processing apparatus according to  claim 20 , wherein said pre-plating treatment comprises a treatment of purifying the surface of the substrate and simultaneously imparting a catalyst to said metal region to activate the surface of the metal region.  
     
     
         22 . A substrate processing apparatus according to  claim 20 , wherein said pretreatment unit has a function to separate the pretreatment liquid used in said pre-plating treatment and a rinsing liquid used in said rinsing treatment from each other after the substrate is treated.  
     
     
         23 . A substrate processing apparatus according to  claim 20 , wherein said pretreatment unit includes a liquid purifying device having a liquid purifying function to measure the concentration of an impurity mixed in said pretreatment liquid in said pre-plating treatment and to remove the impurity when the concentration of the impurity reaches a predetermined value.  
     
     
         24 . A substrate processing apparatus according to  claim 20 , further comprising: 
 a device for measuring at least one of a film thickness and a film property of the alloy film formed on the substrate dried by said post-processing unit.    
     
     
         25 . A substrate processing apparatus according to  claim 24 , wherein a plating condition is changed or the quality of the deposited film is determined based on a measured value from the device for measuring at least one of the film thickness and the film property.  
     
     
         26 . A substrate processing apparatus according to  claim 20 , wherein said pretreatment unit and said electroless plating unit are arranged to process the surface of the substrate which faces in the same orientation.  
     
     
         27 . A substrate processing apparatus according to  claim 20 , wherein said pretreatment unit and said electroless plating unit have a common substrate holding head.  
     
     
         28 . A substrate processing apparatus according to  claim 27 , wherein said substrate holding head is arranged to seal simultaneously or selectively one of a peripheral portion of a face side of the substrate and a peripheral portion of a reverse side of the substrate.  
     
     
         29 . A substrate processing apparatus according to  claim 20 , wherein said pretreatment unit and said plating unit are disposed in a housing having an opening defined in a portion thereof and a function to adjust an atmosphere therein independently of the apparatus in its entirety.  
     
     
         30 . A substrate processing apparatus according to  claim 20 , wherein the substrate processing apparatus is housed in a housing shielded against transmission of light from an external environment.