Coating film forming method and coating film forming apparatus

Abstract

A coating film is formed by the steps of supplying a mixture of a solvent for dissolving a coating liquid and a volatilization suppressing substance for suppressing the volatilization of the solvent onto the surface of the target substrate W, expanding the mixture onto the entire surface of the target substrate W, and supplying a coating liquid onto substantially the central portion of the target substrate W that has received the mixture while rotating the target substrate W thereby expanding the coating liquid outward in the radial direction of the target substrate W thereby forming a coating film.

1 . A coating film forming apparatus for forming a coating film by supplying a coating liquid onto a rotating target substrate, comprising: 
 a substrate holding member for holding a target substrate substantially horizontal;    a rotating mechanism for rotating said substrate holding member;    a mixture supply mechanism for supplying a mixture of a solvent dissolving a coating liquid and a volatilization suppressing substance for suppressing the volatilization of the solvent onto the target substrate held by said substrate holding member; and    a coating liquid supply mechanism for supplying a coating liquid onto substantially the central portion of the target substrate held by said substrate holding member,    wherein said mixture is supplied from said mixture supply mechanism onto the target substrate before formation of said coating film, and the target substrate is rotated by said rotating mechanism thereby permitting the mixture to be diffused onto the entire surface of the target substrate.    
   
   
       2 . The apparatus according to  claim 1 , wherein said mixture supply mechanism comprises a container in which said solvent and said volatilization suppressing substance are mixed in advance thereby forming said mixture and the formed mixture is stored therein, a mixture supply nozzle for supplying said mixture onto said target substrate, and a pipe connecting said container to said mixture supply nozzle.  
   
   
       3 . The apparatus according to  claim 1 , wherein said mixture supply mechanism comprises a mixture supply nozzle for supplying said mixture onto said target substrate and a static mixer arranged in the vicinity of and upstream of said mixture supply nozzle for mixing said solvent and said volatilization suppressing substance, said mixture being supplied from said static mixer into said mixture supply nozzle thereby being spurted from said mixture supply nozzle.  
   
   
       4 . The apparatus according to  claim 1 , wherein said mixture supply mechanism includes a mixture supply nozzle provided with a mixing section for mixing said solvent and said volatilization suppressing substance thereby forming said mixture.  
   
   
       5 . The apparatus according to  claim 1 , wherein said mixture supply mechanism includes a solvent supply nozzle for supplying said solvent onto said target substrate and a volatilization suppressing substance supply nozzle for supplying said volatilization suppressing substance onto said target substrate, said solvent and said volatilization suppressing substance being supplied separately from said solvent supply nozzle and said volatilization suppressing substance supply nozzle onto said target substrate so as to be mixed on said target substrate and, thus, to form a mixture.  
   
   
       6 . The apparatus according to  claim 1 , further comprising a temperature adjusting mechanism for adjusting the temperature of the mixture supplied onto said target substrate.