Chemical treatment apparatus and chemical treatment method

Abstract

There is provided a chemical treatment apparatus for performing a chemical treatment on a treating surface of a wafer etc. by supplying a chemical via a cell. The cell is constituted by a cylindrical inner cell and a cylindrical outer cell with open ends attached to an outer side of the inner cell. The outer cell is axially movable and arbitrarily varies the width of a slit formed between a bottom end of the outer cell and a top surface of the substrate-holding means by the axial movement, thereby adjusting the discharge rate of the chemical and varying the pressure of the chemical. This permits the realization of rapid supply and replacement of the chemical to through holes, non-through holes or grooves. Even in the case of through holes, non-through holes and grooves having small inside diameters and minimum diameters formed in the substrate and having a high aspect ratio, it is possible to rapidly perform the supply and replacement of the chemical to the inside thereof and to perform high-grade chemical treatment with a minimum consumption of the chemical.

What is claimed is:  
     
         1 . A chemical treatment apparatus for performing a treatment by bringing a chemical into contact with a treating surface of a substrate held by a substrate-holding means, comprising: 
 a cylindrical inner cell with a chemical supply means disposed over the substrate; and    a cylindrical outer cell with open ends attached an outer circumference of the inner cell, for performing a chemical treatment of the treating surface of the substrate by filling with the chemical supplied from the chemical supply means,    wherein the outer cell is axially movable, thereby varying the width of a slit formed between a bottom end of the outer cell and a top surface of the substrate-holding means.    
     
     
         2 . The chemical treatment apparatus according to  claim 1 , wherein the width of the slit is varied intermittently at least in three levels.  
     
     
         3 . The chemical treatment apparatus according to  claim 1 , further comprising a rotary mechanism for rotating the substrate-holding means.  
     
     
         4 . The chemical treatment apparatus according to  claim 1 , wherein a flow regulating porous plate is provided at an bottom end of the inner cell in opposition to the substrate.  
     
     
         5 . The chemical treatment apparatus according to  claim 4 , wherein the flow regulating porous plate is in a shape of a dome so as to approach the substrate by more protruding in a central portion than a peripheral portion.  
     
     
         6 . The chemical treatment apparatus according to  claim 4 , wherein the liquid passages of the flow regulating porous plate have an average pore diameter distribution having a center value between 5 μm and 150 μm.  
     
     
         7 . The chemical treatment apparatus according to  claim 4 , wherein the flow regulating porous plate has a thickness of 3 mm to 15 mm.  
     
     
         8 . The chemical treatment apparatus according to  claim 4 , wherein the distance from a central portion of the flow regulating porous plate to the treating surface is within the range of 2% to 30% of an effective diameter of the flow regulating porous plate.  
     
     
         9 . The chemical treatment apparatus according to  claim 1 , which is a plating apparatus, wherein a seed layer comprised of a metal is formed in the treating surface of the substrate and an electrode is provided in the interior of the inner cell, and wherein plating is performed by applying potentials to the electrode and the substrate.  
     
     
         10 . The chemical treatment apparatus according to  claim 9 , wherein through holes, non-through holes or grooves are formed in the treating surface of the substrate.  
     
     
         11 . The chemical treatment apparatus according to  claim 10 , wherein the minimum diameter of the through holes, non-through holes or grooves is 2 μm to 200 μm.  
     
     
         12 . The chemical treatment apparatus according to  claim 10 , wherein the aspect ratio of the through holes, non-through holes or grooves is 1:3 to 1:20.  
     
     
         13 . The chemical treatment apparatus according to  claim 1 , which is an etching apparatus for performing etching.  
     
     
         14 . A chemical treatment method of performing a treatment by bringing a chemical into contact with a treating surface of a substrate held by a substrate-holding means, comprising the steps of: 
 supplying the chemical from a cylindrical inner cell with a chemical supply means disposed over the substrate;    filling with the chemical a cylindrical outer cell with open ends attached to an outer circumference of the inner cell; and    performing a chemical treatment of the treating surface of the substrate using the chemical while axially moving the outer cell to vary the width of a slit formed between a bottom end of the outer cell and a top surface of the substrate-holding means, thereby adjusting the discharge rate of the chemical.    
     
     
         15 . The chemical treatment method according to  claim 14 , wherein the width of the slit varies intermittently at least in three levels to adjust the discharge rate of the chemical, thereby controlling the pressure of the chemical in the cell.  
     
     
         16 . The chemical treatment method according to  claim 14 , wherein the substrate-holding means is rotated while performing the chemical treatment.  
     
     
         17 . The chemical treatment method according to  claim 14 , wherein a flow regulating porous plate is provided in a bottom end of the inner cell in opposition to the substrate and the chemical is temporarily stored in the inner cell and thereafter supplied to the substrate via the flow regulating porous plate.  
     
     
         18 . The chemical treatment method according to  claim 14 , which is plating, wherein a seed layer composed of a metal is formed beforehand on the treating surface of the substrate, an electrode is provided in the interior of the inner cell, and plating is performed by applying potentials to the electrode and the substrate.  
     
     
         19 . The chemical treatment method according to  claim 18 , wherein through holes, non-through holes or grooves are formed beforehand in the treating surface of the substrate.  
     
     
         20 . The chemical treatment method according to  claim 14 , which is etching.