Substrate treatment apparatus and substrate treatment method

A substrate treatment apparatus comprising:

• cleaning and rinse modules configured to clean and rinse a surface of a substrate provided with a pattern;
• a solidifying agent containing liquid supplying module configured to supply a solidifying agent containing liquid that contains a solidifying agent to the cleaned and rinsed surface of the substrate;
• a precipitation module configured to precipitate the solidifying agent as solid on the surface of the substrate;
• and
• a decomposition module configured to decompose and gasify the solid to remove the solid from the surface of the substrate,
• wherein
• the solidifying agent contains an ammonium salt, and
• the ammonium salt contains an ammonium ion or an ion having a structure in which at least one of four hydrogen atoms of an ammonium ion is substituted with another atom or atom group.