Substrate processing method and substrate processing apparatus

A substrate processing method comprising:

• a substrate holding step of holding a substrate horizontally by a substrate holding unit, the substrate having an upper surface on which a pattern is formed;
• a liquid film forming step of forming, while rotating the substrate at a rotation speed, a liquid film of an organic solvent with which a whole area of the upper surface of the substrate is covered in order to replace a processing liquid existing on the upper surface of the substrate with an organic solvent liquid;
• an organic solvent vapor forming step of forming an atmosphere of an organic solvent vapor at surroundings of the whole area of an upper surface of the liquid film of the organic solvent;
• a thin film holding step of thinning the liquid film of the organic solvent by rotating the substrate at a first rotational speed which is higher than the rotation speed in the liquid film forming step while keeping the surroundings of the whole area of the upper surface of the liquid film of the organic solvent in the atmosphere of the organic solvent vapor, and holding a resulting thin film of the organic solvent on the upper surface of the substrate such that the whole area of the upper surface of the substrate is covered with the resulting thin film of the organic solvent while keeping the resulting thin film to be uniform in thickness thereof;
• and
• a thin-film removing step of removing the resulting thin film of the organic solvent from the upper surface of the substrate after the thin film holding step,
• the thin-film removing step including a rotation step of rotating the substrate at a second rotational speed, wherein
• the organic solvent vapor forming step decelerates the rotation of the substrate from the rotation speed to a puddle speed lower than the rotation speed, and fills the surroundings of the whole area of the upper surface of the liquid film with the organic solvent vapor while rotating the substrate at the puddle speed,
• the thin film holding step starts after the surroundings of the whole area of the upper surface of the liquid film have been filled with the organic solvent vapor,
• the thin film holding step keeps a state in which the surroundings of the whole area of the upper surface of the liquid film is filled with the organic solvent vapor,
• the first rotational speed and the second rotational speed are equal to each other, and
• the thin film removing step is a spin drying step.