Liquid treatment using thin liquid layer

Abstract

A treating head having a treating surface and a substrate treatment surface define a thin fluid gap that is filled with reactant liquid to form a thin liquid layer on the substrate for conducting a liquid chemical reaction treatment or other liquid treatment of the substrate. The thin liquid layer has a volume in a range of about from 50 ml to 500 ml. Preferably, the chemical composition, temperature, and other properties of liquid in the thin liquid layer are dynamically variable.

1 . An apparatus for thin-liquid-layer treatment of a surface of an integrated circuit substrate, comprising: 
 a substrate holder;    a treating head proximate to the substrate holder, the treating head including a head surface that forms a thin fluid gap between the head surface and a substrate treatment surface when a substrate is present in the substrate holder; and    a liquid inlet tube for flowing liquid into a thin fluid gap.    
     
     
         2 . An apparatus as in  claim 1  wherein the thin-liquid-layer treatment comprises a treatment selected from a group consisting of a chemical liquid reaction treatment and a cleaning treatment.  
     
     
         3 . An apparatus as in  claim 1  wherein the thin-liquid-layer treatment comprises a chemical liquid reaction treatment selected from a group consisting of electroless metal plating, etching, electrolytic plating, electrolytic etching, metal-oxide deposition, and liquid dielectric deposition.  
     
     
         4 . An apparatus as in  claim 1  wherein the treating head comprises a peripheral edge corresponding substantially in shape to an outer edge of an integrated circuit wafer, and wherein the peripheral edge forms a peripheral slit with the outer edge of the integrated circuit wafer when the wafer is in the substrate holder.  
     
     
         5 . An apparatus as in  claim 4  wherein the peripheral slit comprises a width in a range of about from 0.0 mm to 0.5 mm.  
     
     
         6 . An apparatus as in  claim 1  wherein a thin fluid gap comprises a width substantially in a range of about from 0.1 mm to 4 mm.  
     
     
         7 . An apparatus as in  claim 1  wherein a thin fluid gap comprises a volume in a range of about from 30 microliters per cm 2  to 300 microliters per cm 2  of substrate treatment surface.  
     
     
         8 . An apparatus as in  claim 1  wherein the substrate holder further comprises a plurality of support pins for supporting a substrate in the substrate holder.  
     
     
         9 . An apparatus as in  claim 1 , further comprising a rotary head shaft connected to the treating head for rotating the treating head.  
     
     
         10 . An apparatus as in  claim 1  wherein the fluid gap is dynamically variable.  
     
     
         11 . An apparatus as in  claim 1 , further comprising a head heater for heating the treating head.  
     
     
         12 . An apparatus as in  claim 1 , further comprising a multizone head heater.  
     
     
         13 . An apparatus as in  claim 1  wherein the liquid inlet tube is integral with the treating head.  
     
     
         14 . An apparatus as in  claim 1 , further comprising: 
 a manifold cavity disposed in the treating head;    a manifold inlet for providing fluidic communication between a liquid source and the manifold cavity; and    a plurality of liquid inlet tubes integral with the treating head for flowing liquid from the manifold cavity into a fluid gap when a substrate is present in the substrate holder.    
     
     
         15 . An apparatus as in  claim 14 , further comprising a manifold recirculation tube between the manifold cavity and the liquid source.  
     
     
         16 . An apparatus as in  claim 14 , further comprising a bubble removal tube in fluidic communication with the manifold cavity.  
     
     
         17 . An apparatus as in  claim 1 , further comprising: 
 a treating liquid source;    a containment chamber containing the substrate holder and having an outlet drain; and    a recycling tube between the outlet drain and the treating liquid source.    
     
     
         18 . An apparatus as in  claim 1 , further comprising: 
 a containment chamber containing the substrate holder; and    a liquid diversion system wherein the liquid diversion system includes a collection trough, and the collection trough is disposed in a containment chamber substantially radially outwards from the substrate holder.    
     
     
         19 . An apparatus as in  claim 1 , further comprising a substrate heater integral with the substrate holder for heating a substrate from the backside of the substrate.  
     
     
         20 . An apparatus as in  claim 1  wherein the substrate holder is a differential pressure chuck comprising an annular collar disposed in the containment vessel, the annular collar including an inside collar edge, the inside collar edge forming a narrow flow passage between the inside collar edge and the outer edge of a substrate wafer when a wafer is present in the wafer holder.  
     
     
         21 . An apparatus as in  claim 20  wherein the narrow passage has a width in a range of about from 0.2 mm to 7 mm.  
     
     
         22 . An apparatus as in  claim 1 , further comprising a liquid heater for heating liquid from a treating liquid source, the liquid heater being disposed upstream from the liquid inlet tube.  
     
     
         23 . An apparatus as in  claim 22 , further comprising: 
 a liquid source tube from a treating liquid source;    a recirculation tube for recirculating treating liquid from a liquid source tube back to the treating liquid source; and    a liquid cooler for cooling recirculating treating liquid.    
     
     
         24 . An apparatus as in  claim 1 , further comprising a plurality of gas injection ports proximate to the wafer holder for injecting inert gas proximate to a wafer edge when a substrate wafer is present in the substrate holder.  
     
     
         25 . An apparatus as in  claim 1 , further comprising: 
 a plurality of treating liquid sources including a first treating liquid source and a second treating liquid source; and    a liquid mixer, the mixer being located proximate to the treating head, for mixing a first treating liquid from the first treating liquid source and a second treating liquid from the second treating liquid source.    
     
     
         26 . An apparatus as in  claim 23  wherein a first liquid source comprises an activation liquid source, and a second liquid source comprises a plating solution source.  
     
     
         27 . An apparatus as in  claim 1 , further comprising a head array, the head array including a plurality of treating heads.  
     
     
         28 . An apparatus as in  claim 1  wherein the head surface has a shape that is substantially flat.  
     
     
         29 . An apparatus as in  claim 1 , further comprising a magnetic source located in the treating head for creating a magnetic field in a thin fluid gap to clean a liquid in the gap.  
     
     
         30 . An apparatus as in  claim 1  further comprising: 
 a magnetic source for creating a magnetic field in a thin fluid gap; and  
 a magnetic sensor for detecting an amount of metal present on a substrate present in the substrate holder.  
 
     
     
         31 . An apparatus as in  claim 1  wherein said treating head comprises a megasonic cleaning head.  
     
     
         32 . An apparatus as in  claim 1 , further comprising a gas inlet tube for injecting wafer release gas into a space selected from a group consisting of a manifold cavity and a thin fluid gap.  
     
     
         33 . An apparatus as in  claim 1  wherein the liquid inlet tube is suitable for injecting wafer release gas into a thin fluid gap.  
     
     
         34 . An apparatus as in  claim 1 , further comprising a gas release tube in fluidic communication with the liquid inlet tube to release gas located in a thin fluid gap.  
     
     
         35 . An apparatus as in  claim 1 , further comprising: 
 a light source; and    an optical sensor for measuring an optical property related to an amount of material deposited on a substrate treatment surface.    
     
     
         36 . An apparatus as in claim- 35  wherein said optical property is selected from a group consisting of optical reflectivity, optical transmittance, and optical spectrum.  
     
     
         37 . A method of liquid treatment of a surface of an integrated circuit substrate, comprising: 
 placing an integrated circuit substrate having a treatment surface in a substrate holder;    disposing a treating head having a head surface proximate to the treatment surface, the head surface and the treatment surface thereby defining a thin fluid gap; and    flowing liquid into the thin fluid gap to form a thin liquid layer.    
     
     
         38 . A method as in  claim 37  wherein flowing liquid into the thin fluid gap comprises dynamically varying a property of the liquid.  
     
     
         39 . A method as in  claim 37  wherein disposing the treating head proximate to the treatment surface comprises forming a peripheral slit between a peripheral edge of the treating head and an outer edge of the substrate.  
     
     
         40 . A method as in  claim 39  wherein forming a peripheral slit comprises forming a slit having a width in a range of about from 0.0 mm to 0.5 mm.  
     
     
         41 . A method as in  claim 39 , further comprising dynamically varying the peripheral slit.  
     
     
         42 . A method as in  claim 37  wherein disposing the treating head proximate to the treatment surface comprises defining a thin fluid gap having a volume in a range of about from 30 microliters per cm 2  to 300 microliters per cm 2  of substrate treatment surface.  
     
     
         43 . A method as in  claim 42 , further comprising dynamically varying the volume of the thin fluid gap.  
     
     
         44 . A method as in  claim 37  wherein the liquid treatment comprises a treatment selected from a group consisting of: electroless metal plating, electroless chemical etching, electrolytic plating, electrolytic etching, metal-oxide deposition, and liquid dielectric deposition.  
     
     
         45 . A method as in  claim 37 , further comprising rotating the substrate.  
     
     
         46 . A method as in  claim 45 , further comprising dynamically varying a rotational speed of the substrate.  
     
     
         47 . A method as in  claim 37 , further comprising rotating the treating head.  
     
     
         48 . A method as in  claim 47 , further comprising dynamically varying a rotational speed of the treating head.  
     
     
         49 . A method as in  claim 37 , further comprising heating the treating head.  
     
     
         50 . A method as in  claim 49 , further comprising dynamically varying the heating of the treating head.  
     
     
         51 . A method as in  claim 49  wherein heating the treating head comprises creating a nonuniform temperature profile in the treating head.  
     
     
         52 . A method as in  claim 37  wherein flowing liquid into the fluid gap comprises: 
 flowing liquid into the fluid gap during a first period of time; and then substantially ceasing flowing liquid into the fluid gap during a second period of time.  
 
     
     
         53 . A method as in  claim 37  wherein flowing liquid into the fluid gap comprises flowing liquid into the fluid gap at a flowrate in a range of about from 0 ml/min. to 2000 ml/min.  
     
     
         54 . A method as in  claim 37  wherein flowing liquid into the fluid gap comprises dynamically varying a flow rate of liquid into the fluid gap.  
     
     
         55 . A method as in  claim 37  wherein flowing liquid into the fluid gap comprises dynamically varying a composition of the liquid.  
     
     
         56 . A method as in  claim 37 , further comprising: 
 flowing a first treating liquid into a mixer;    flowing a second treating liquid into the mixer to form a mixed liquid with the first treating liquid; and    then flowing the mixed liquid into the fluid gap.    
     
     
         57 . A method as in  claim 56 , further comprising: 
 varying a property of the mixed liquid upstream of the fluid gap to form a second mixed liquid; and    then flowing the second mixed liquid into the fluid gap.    
     
     
         58 . A method as in  claim 37  wherein flowing liquid into the fluid gap comprises flowing liquid through a showerhead-type manifold.  
     
     
         59 . A method as in  claim 37 , further comprising recycling liquid from a containment space to a treating liquid source.  
     
     
         60 . A method as in  claim 37 , further comprising diverting treatment liquid from a containment space using a liquid diversion system.  
     
     
         61 . A method as in  claim 60  wherein diverting treatment liquid comprises collecting liquid in a collection trough disposed substantially radially outwards from the substrate.  
     
     
         62 . A method as in  claim 37 , further comprising recirculating a portion of liquid to a liquid source instead of flowing the portion of liquid into the fluid gap.  
     
     
         63 . A method as in  claim 37 , further comprising heating the liquid before flowing the liquid into the fluid gap.  
     
     
         64 . A method as in  claim 37 , further comprising: 
 heating treatment liquid upstream of the fluid gap;    diverting a recirculation-portion of the treatment liquid instead of flowing the recirculation-portion into the fluid gap;    cooling the recirculation-portion of treatment liquid; and    then flowing the recirculation-portion of treatment liquid to a treatment liquid source.    
     
     
         65 . A method as in  claim 37  wherein flowing liquid into the fluid gap comprises flowing a pre-wetting liquid into the thin fluid gap.  
     
     
         66 . A method as in  claim 37  wherein flowing liquid into the fluid gap comprises flowing a rinsing liquid into the thin fluid gap.  
     
     
         67 . A method as in  claim 37 , further comprising injecting wafer release gas into the thin fluid gap.  
     
     
         68 . A method as in  claim 67  wherein injecting wafer release gas comprises injecting gas through a tube selected from a group consisting of a liquid inlet tube and a gas inlet tube.  
     
     
         69 . A method as in  claim 37  wherein flowing liquid into the fluid gap comprises flowing liquid from a liquid source into a manifold cavity located in the treating head.  
     
     
         70 . A method as in  claim 37 , further comprising diverting a recirculation-portion of liquid from the manifold cavity back to the liquid source.  
     
     
         71 . A method as in  claim 37 , further comprising heating the substrate from the backside of the substrate.  
     
     
         72 . A method as in  claim 71 , further comprising dynamically varying the heating.  
     
     
         73 . A method as in  claim 37 , further comprising creating a pressure differential between an upper containment chamber above the substrate and a lower containment chamber below the substrate, wherein the pressure in the upper containment chamber is greater than in the lower containment chamber.  
     
     
         74 . A method as in  claim 73  wherein creating a pressure differential comprises drawing a partial vacuum in the lower containment chamber, thereby drawing gas from the upper containment chamber around the outer edge of the substrate through a narrow passage between the inside collar edge of an annular collar and the outer edge of the substrate.  
     
     
         75 . A method as in  claim 74  wherein the narrow passage has a width in a range of about from 1 mm to 7 mm.  
     
     
         76 . A method as in  claim 37  wherein flowing liquid into the fluid gap comprises flowing an electroless plating solution into the fluid gap.  
     
     
         77 . A method as in  claim 76  wherein flowing an electroless plating solution into the fluid gap comprises: 
 flowing a nucleation solution into the fluid gap; and  
 then flowing a growth solution into the fluid gap.  
 
     
     
         78 . A method as in  claim 77 , further comprising flowing an activator solution into the fluid gap before flowing the nucleation solution.  
     
     
         79 . A method as in  claim 37  wherein flowing liquid into the fluid gap comprises flowing an etching solution.  
     
     
         80 . A method of depositing a foreign-metal layer onto a base-metal material on a treatment surface of an integrated circuit substrate using a thin liquid layer, comprising: 
 treating the treatment surface with a nucleation-phase reactant liquid containing foreign-metal atoms under nucleation-phase reaction conditions; and    thereafter treating the treatment surface by forming a thin liquid layer of a growth-phase reactant liquid containing foreign-metal atoms under growth-phase reaction conditions, the nucleation-phase liquid chemical reaction conditions being different from the growth-phase liquid chemical reaction conditions.    
     
     
         81 . A method as in  claim 80  wherein treating the treatment surface with a nucleation-phase reactant liquid comprises a process selected from the group consisting of: forming a thin liquid layer of the nucleation-phase reacting liquid on the treatment surface, and spraying the treatment surface with nucleation-phase reactant liquid.  
     
     
         82 . A method as in  claim 80 , further comprising activating the base-metal material using an activator liquid prior to treating with the nucleation reactant liquid.  
     
     
         83 . A method as in  claim 82  wherein activating the base-metal material comprises forming a thin liquid layer of activator liquid on the treatment surface.  
     
     
         84 . A method as in  claim 83  wherein activating the base-metal material comprises forming a thin liquid layer comprising DMAB.  
     
     
         85 . A method as in  claim 80  wherein the foreign-metal atoms comprise cobalt.  
     
     
         86 . A method as in  claim 80  wherein the base-metal material comprises substantially copper.  
     
     
         87 . A method of depositing a foreign-metal layer onto a base-metal material on a treatment surface of an integrated circuit substrate, comprising: 
 treating the treatment surface with a nucleation-phase reactant liquid containing foreign-metal atoms under nucleation-phase reaction conditions; and    thereafter treating the treatment surface with a growth-phase reactant liquid containing foreign-metal atoms under growth-phase reaction conditions, the nucleation-phase liquid chemical reaction conditions being different from the growth-phase liquid chemical reaction conditions.    
     
     
         88 . A method as in  claim 87 , further comprising activating the base-metal material using an activator liquid prior to treating with the nucleation reactant liquid.  
     
     
         89 . A method as in  claim 87  wherein the foreign-metal atoms comprise cobalt.  
     
     
         90 . A method as in  claim 87  wherein the base-metal material comprises substantially copper.