Substrate processing method and substrate processing apparatus

Abstract

A substrate processing method includes a processing liquid film forming step of supplying a processing liquid, containing a sublimable substance, to a pattern forming surface of a substrate, to form a processing liquid film on the pattern forming surface, a temperature maintaining step of maintaining a temperature of the processing liquid film, formed on the pattern forming surface, in a temperature range not lower than a melting point of the sublimable substance and lower than a boiling point of the sublimable substance, a film thinning step of thinning the processing liquid film while the temperature of the processing liquid film is in the temperature range, a freezing step of making the processing liquid film, thinned by the film thinning step, freeze on the pattern forming surface after the temperature maintaining step to form a frozen body of the sublimable substance, and a sublimating step of sublimating the frozen body to remove the frozen body from the pattern forming surface.

What is claimed is: 
     
         1 . A substrate processing method comprising:
 a mixed liquid film forming step of supplying, to a front surface of a substrate, a mixed processing liquid, being a mixed processing liquid, in which a first sublimable substance and a first additive, differing from the first sublimable substance, are mixed, and being lower in freezing point than the first sublimable substance, to form a liquid film of the mixed processing liquid on the front surface of the substrate;   a freezing step of making the liquid film of the mixed processing liquid freeze to form a frozen body; and   a sublimating step of vaporizing and removing the first sublimable substance, contained in the frozen body, from the front surface of the substrate.   
     
     
         2 . The substrate processing method according to  claim 1 , wherein the freezing point of the first sublimable substance is higher than ordinary temperature and a freezing point of the mixed processing liquid is lower than ordinary temperature. 
     
     
         3 . The substrate processing method according to  claim 1 , wherein the first additive includes a solvent without a sublimating property. 
     
     
         4 . The substrate processing method according to  claim 1 , wherein the first additive includes a second sublimable substance. 
     
     
         5 . The substrate processing method according to  claim 1 , wherein the freezing point of the first additive is lower than the freezing point of the first sublimable substance. 
     
     
         6 . The substrate processing method according to  claim 1 , further comprising: a mixed liquid preparing step of mixing the first sublimable substance and the first additive to prepare the mixed processing liquid; and
 wherein the mixed liquid film forming step includes a step of supplying the mixed processing liquid, prepared by the mixed liquid preparing step, to the front surface of the substrate.   
     
     
         7 . The substrate processing method according to  claim 1 , wherein the freezing step includes a step of supplying a mixed cooling medium, which is a mixed cooling medium with a cooling medium and a second additive being mixed and is lower in freezing point than the cooling medium, to a rear surface at an opposite side to the front surface of the substrate to cool the liquid film of the mixed processing liquid. 
     
     
         8 . The substrate processing method according to  claim 7 , wherein the second additive is the same as the first additive. 
     
     
         9 . The substrate processing method according to  claim 1 , further comprising: a film thinning step of thinning the liquid film of the mixed processing liquid while a temperature of the liquid film of the mixed processing liquid is in a temperature range not lower than the freezing point of the mixed processing liquid and lower than a boiling point of the mixed processing liquid; and
 wherein the freezing step includes a step of freezing the liquid film of the mixed processing liquid thinned by the film thinning step.   
     
     
         10 . A substrate processing apparatus comprising:
 a mixed processing liquid supplying unit which supplies, to a front surface of a substrate, a mixed processing liquid, being a mixed processing liquid, in which a first sublimable substance and a first additive, differing from the first sublimable substance, are mixed, and being lower in freezing point than the first sublimable substance;   a freezing unit which makes a liquid film of the mixed processing liquid freeze; and   a controller, controlling the mixed processing liquid supplying unit and the freezing unit; and   wherein the controller is programmed to execute a mixed liquid film forming step of supplying the mixed processing liquid to the front surface of the substrate by the mixed processing liquid supplying unit to form the liquid film of the mixed processing liquid on the front surface of the substrate, a freezing step of making the liquid film of the mixed processing liquid freeze by the freezing unit to form a frozen body, and a sublimating step of vaporizing and removing the first sublimable substance, contained in the frozen body, from the front surface of the substrate.