Substrate treatment apparatus

Abstract

An inventive substrate treatment method includes a silylation step of supplying a silylation agent to a substrate, and an etching step of supplying an etching agent to the substrate after the silylation step. The method may further include a repeating step of repeating a sequence cycle including the silylation step and the etching step a plurality of times. The cycle may further include a rinsing step of supplying a rinse liquid to the substrate after the etching step. The cycle may further include a UV irradiation step of irradiating the substrate with ultraviolet radiation after the etching step. The method may further include a pre-silylation or post-silylation UV irradiation step of irradiating the substrate with the ultraviolet radiation before or after the silylation step.

What is claimed is: 
     
         1 . A substrate treatment apparatus that is configured to treat a substrate formed with a silicon oxide film and a silicon nitride film, the apparatus comprising:
 an apparatus frame in which a silylation position and an etching position are defined,   a silylation agent supply unit that is configured to supply a silylation agent to the substrate held at the silylation position; and   an etching agent supply unit that is configured to supply an etching agent for selective etching of the silicon nitride film to the substrate which has been subjected to a silylation treatment by the silylation agent and is held at the etching position, thereby selectively etching the silicon nitride film with suppressed etching of the silicon oxide film.   
     
     
         2 . The substrate treatment apparatus according to  claim 1 , wherein the silylation agent supply unit is provided in a silylation unit ( 7   a ) which includes
 a chamber ( 8 ),   a substrate holding base ( 14 ) configured to hold the substrate at the silylation position defined in the chamber, and   the silylation agent supply unit having a silylation agent inlet pipe ( 28 ) configured to supply the silylation agent in a form of vapor toward the substrate held by the substrate holding base.   
     
     
         3 . The substrate treatment apparatus according to  claim 2 , wherein the etching agent supply unit is provided in an etching unit ( 76 ) which includes
 a chamber ( 41 ),   a spin chuck ( 38 ) configured to hold the substrate at the etching position,   the etching agent supply unit having an etching agent nozzle ( 39 ) configured to supply the etching agent toward the substrate held by the spin chuck, and   a rinse liquid nozzle ( 40 ) configured to supply a rinse liquid toward the substrate held by the spin chuck.   
     
     
         4 . The substrate treatment apparatus according to  claim 3 , further comprising a transfer robot (CR) configured to unload the substrate from the silylation unit ( 7   a ) after the substrate has subjected to the silylation treatment, and then to load the substrate into the etching unit ( 7   b ). 
     
     
         5 . The substrate treatment apparatus according to  claim 1 , wherein the silylation agent supply unit is provided in a silylation unit ( 207   a ) which includes
 a chamber ( 41 ),   a spin chuck ( 38 ) configured to hold the substrate at the silylation position, and   the silylation agent supply unit having a silylation agent outlet port ( 259 ) configured to supply the silylation agent toward the substrate held by the spin chuck ( 38 ).   
     
     
         6 . The substrate treatment apparatus according to  claim 5 , wherein
 the silylation unit further includes a shield plate ( 252 ) arranged above the spin chuck ( 38 ), and   the silylation agent outlet port ( 259 ) is open toward a side of the shield plate opposing to the spin chuck ( 38 ).   
     
     
         7 . The substrate treatment apparatus according to  claim 6 , wherein a gas outlet port ( 260 ,  262 ) is defined in the shield plate on a side opposing to the spin chuck. 
     
     
         8 . The substrate treatment apparatus according to  claim 7 , wherein the gas outlet port includes an annular gas outlet port ( 262 ) surrounding the silylation agent outlet port ( 259 ). 
     
     
         9 . The substrate treatment apparatus according to  claim 6 , wherein the silylation agent supply unit is configured to supply the silylation agent in a form of a silylation agent vapor through the silylation agent outlet port ( 259 ). 
     
     
         10 . The substrate treatment apparatus according to  claim 6 , wherein the silylation agent supply unit is configured to supply the silylation agent in a form of a silylation agent liquid through the silylation agent outlet port ( 259 ). 
     
     
         11 . The substrate treatment apparatus according to  claim 6 , wherein the shield plate ( 252 ) includes a disk portion ( 254 ), and a tubular portion ( 255 ) provided along an outer periphery of the disk portion ( 254 ) and extending vertically downward from the outer periphery. 
     
     
         12 . The substrate treatment apparatus according to  claim 6 , wherein the shield plate ( 352 ) includes a disk portion ( 254 ), and a tubular portion ( 355 ) provided along an outer periphery of the disk portion ( 254 ) and flared downward outward from the outer periphery. 
     
     
         13 . The substrate treatment apparatus according to  claim 7 , wherein the spin chuck ( 38 ) of the silylation unit ( 207   a ) is configured to hold the substrate at the etching portion, and
 the etching agent supply unit is configured to supply the etching agent to the substrate held at the etching position by the spin chuck ( 38 ).   
     
     
         14 . The substrate treatment apparatus according to  claim 13 , wherein
 the silylation unit ( 207   a ) further includes a shield plate lift mechanism ( 269 ) configured to move up and down the shield plate ( 252 ) between an adjacent position at which the shield plate ( 252 ) is located adjacent an upper surface of the substrate and a retracted position at which the shield plate ( 252 ) is retracted above the spin chuck ( 38 ), and   the silylation unit ( 207   a ) is configured to   spout an inert gas through the gas outlet port to replace an atmosphere of the substrate with the inert gas with the shield plate ( 252 ) located at the adjacent position by the shield plate lift mechanism,   supply the silylation agent, after the atmosphere replacement, through the silylation agent outlet port ( 259 ) so as to silylate the substrate, and   supply the etching agent, after the silylation agent supply, by the etching agent supply unit to the substrate with the shield plate ( 252 ) located at the retracted position by the shield plate lift mechanism.   
     
     
         15 . The substrate treatment apparatus according to  claim 13 , wherein the silylation unit ( 207   a ) further includes a rinse liquid supply unit configured to supply a rinse liquid to the substrate held at the etching position after the etching agent supply. 
     
     
         16 . The substrate treatment apparatus according to  claim 15 , wherein the silylation unit is configured to cause the rise liquid supply unit to supply the rise liquid to the substrate held at the etching position after the etching agent supply with the shield plate located at the retracted position by the shield plate lift mechanism. 
     
     
         17 . The substrate treatment apparatus according to  claim 1 , further comprising a UV irradiation unit configured to irradiate the substrate held at the silylation position with ultraviolet radiation. 
     
     
         18 . The substrate treatment apparatus according to  claim 1 , wherein the etching agent supply unit is configured to supply the etching agent to the substrate not longer than 200 seconds. 
     
     
         19 . The substrate treatment apparatus according to  claim 1 , wherein the silylation agent supply unit is configured to supply the silylation agent including at least one selected from the group consisting of TMSI (N-trimethylsilylimidazole), BSTFA (N,O-bis(trimethylsilyl)trifluoroacetamide), BSA (N,O-bis(trimethylsilyl)acetamide), MSTFA (N-methyl-N-trimethylsilyltrifluoroacetamide), TMSDMA (N-trimethylsilyldimethylamine), TMSDEA (N-trimethylsilyldiethylamine), MTMSA (N,O-bis(trimethylsilyl)trifluoroacetamide), TMCS (trimethylchlorosilane) with base, HMDS (hexamethyldisilazane), amines each having a hydrophobic group, organic silicon compounds, TMS (tetramethylsilane), fluorinated alkylchlorosilanes, alkyldisilazanes, dimethylsilyldimethylamine, dimethylsilyldiethylamine, bis(dimethylamino)dimethylsilane and organosilane compounds. 
     
     
         20 . The substrate treatment apparatus according to  claim 1 , wherein the etching agent supply unit is configured to supply the etching agent including at least one selected from the group consisting of a liquid mixture containing hydrofluoric acid and ethylene glycol, a phosphoric acid aqueous solution, and hydrofluoric acid.