Wet etching apparatus and wet etching method using ultraviolet light

Abstract

A substrate having a film to be etched is held on a rotating stage. While rotating the substrate, a chemical solution containing an etchant is supplied onto the substrate from a nozzle. A lamp house with a drive unit is positioned so that the distance between the substrate and a glass window of the lamp house becomes 2 to 5 mm, the lamp house accommodating a lamp generating ultraviolet light. The ultraviolet light irradiates the film through the chemical solution. The ultraviolet light has a higher energy than the binding energy of constituent molecules of the film.

1 . A wet etching apparatus comprising: 
 a chemical-solution supply component for supplying a chemical solution to a film to be processed, the film being supported by a substrate, and    an ultraviolet-light radiating component for irradiating the film with ultraviolet light through the chemical solution.    
     
     
         2 . The wet etching apparatus according to  claim 1 , wherein the ultraviolet-light radiating component radiates ultraviolet light having an energy higher than binding energy of constituent molecules of the film.  
     
     
         3 . The wet etching apparatus according to  claim 1 , further comprising a drive unit for moving the ultraviolet-light radiating component, wherein the ultraviolet-light radiating component is moved at a location 2 mm to 5 mm above a surface of the film, when the film is being irradiated with the ultraviolet light.  
     
     
         4 . The wet etching apparatus according to  claim 1 , wherein the ultraviolet-light radiating component comprises: 
 a light source generating the ultraviolet light;    a storage component for accommodating the light source and having a light-transmitting window for facing the film; and    a nozzle in the chemical-solution supply component, disposed at a gap between the light-transmitting window and the film, for continuously supplying the chemical solution in the gap.    
     
     
         5 . The wet etching apparatus according to  claim 4 , further comprising a stage for holding the substrate, the stage including a pair of guides parallel to the nozzle, for sandwiching the substrate.  
     
     
         6 . The wet etching apparatus according to  claim 4 , including a layer of a surface-active agent located at a surface of the light-transmitting window and contacting the chemical solution.  
     
     
         7 . The wet etching apparatus according to  claim 4 , wherein the chemical-solution supply component comprises: 
 a switching valve connected to the nozzle through a pipe and for switching between a supply of the chemical solution and a supply of ultra-pure water;    a pipe for supplying the chemical solution and connected to the switching valve; and    a pipe for supplying the ultra-pure water and connected to the switching valve.    
     
     
         8 . A method for wet etching of a film, comprising: 
 supplying a chemical solution to a film to be processed, the film being disposed on a substrate; and    irradiating the film with ultraviolet light through the chemical solution.    
     
     
         9 . The method for wet etching according to  claim 8 , including supplying the chemical solution and irradiating the film with ultraviolet light simultaneously.  
     
     
         10 . The method for wet etching according to  claim 8 , including irradiating the film with ultraviolet light having an energy higher than the binding energy of constituent molecules of the film.  
     
     
         11 . The method for wet etching according to  claim 8 , wherein the film is a high-k dielectric film that has been annealed.