TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The silylation agent supply unit is provided in a silylation unit 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. The etching agent supply unit is provided in an etching unit which includes a chamber, a spin chuck configured to hold the substrate at the etching position, the etching agent supply unit having an etching agent nozzle configured to supply the etching agent toward the substrate held by the spin chuck, and a rinse liquid nozzle configured to supply a rinse liquid toward the substrate held by the spin chuck. The substrate treatment apparatus further comprises: a transfer robot configured to unload the substrate from the silylation unit after the substrate has subjected to the silylation treatment, and then to load the substrate into the etching unit; and a UV irradiation unit configured to irradiate the substrate held at the silylation position with ultraviolet radiation. The silylation agent supply unit is provided in a silylation unit which includes a chamber, a spin chuck configured to hold the substrate at the silylation position, and the silylation agent supply unit having a silylation agent outlet port configured to supply the silylation agent toward the substrate held by the spin chuck. The silylation unit further includes a shield plate arranged above the spin chuck, and the silylation agent outlet port is open toward a side of the shield plate opposing to the spin chuck. In the substrate treatment apparatus a gas outlet port is defined in the shield plate on a side opposing to the spin chuck. The gas outlet port includes an annular gas outlet port surrounding the silylation agent outlet port. 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. 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. The shield plate includes a disk portion, and a tubular portion provided along an outer periphery of the disk portion and extending vertically downward from the outer periphery. The shield plate includes a disk portion, and a tubular portion provided along an outer periphery of the disk portion and flared downward outward from the outer periphery. The spin chuck (38) of the silylation unit 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. The silylation unit further includes a shield plate lift mechanism configured to move up and down the shield plate between an adjacent position at which the shield plate is located adjacent an upper surface of the substrate and a retracted position at which the shield plate is retracted above the spin chuck, and the silylation unit 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 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 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 located at the retracted position by the shield plate lift mechanism. The silylation unit 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. 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. The etching agent supply unit is configured to supply the etching agent to the substrate not longer than 200 seconds. The silylation agent supply unit is configured to supply the silylation agent including at least one of N-trimethylsilylimidazole, N,O-bis(trimethylsilyl)trifluoroacetamide, N,O-bis(trimethylsilyl)acetamide, N-methyl-Ntrimethylsilyltrifluoroacetamide, N-trimethylsilyldimethylamine, N-trimethylsilyldiethylamine, N,O-bis(trimethylsilyl) trifluoroacetamide, trimethylchlorosilane with base, hexamethyldisilazane, amines each having a hydrophobic group, organic silicon compounds, tetramethylsilane, fluorinated alkylchlorosilanes, alkyldisilazanes, dimethylsilyldimethylamine, dimethylsilyldiethylamine, bis(dimethylamino)dimethylsilane and organosilane compounds. The etching agent supply unit is configured to supply the etching agent including at least one of a liquid mixture containing hydrofluoric acid and ethylene glycol, a phosphoric acid aqueous solution, and hydrofluoric acid.