Substrate treatment method and substrate treatment apparatus

A substrate treatment apparatus which treats a silicon substrate on which a nitride film is formed using liquid etchant which contains phosphoric acid, said substrate treatment apparatus comprising:

• an etching treatment section which is configured to provide a suitable quantity of liquid etchant to each substrate which is fed one at a time so as to etch said substrate and remove the nitride film;
• wherein said etching treatment section includes:
• a substrate spinner which is configured to make each substrate which is fed one at a time spin,
• a liquid etchant feeder which is configured to provide a suitable quantity of liquid etchant to a surface of said substrate which is spun by said substrate spinner,
• a hydrofluoric acid feeder fluidly connected to a hydrofluoric acid supply, and
• a liquid storing section which is configured to store used liquid etchant which is provided to the surface of said spinning substrate and is splattered from the surface of said substrate,
• and
• said substrate treatment apparatus further comprising:
• a controller which is configured to control the etching treatment section so that hydrofluoric acid feeder provides a suitable amount of hydrofluoric acid under a predetermined temperature environment from the hydrofluoric acid supply to the liquid storing section and the liquid etchant feeder provides a suitable quantity of liquid etchant to the surface of each of a predetermined number of substrates treated one at a time in a state where the liquid storing section stores the suitable amount of hydrofluoric acid for the quantity of liquid etchant used for treatment of the predetermined number of substrates to mix and react the used liquid etchant and the suitable amount of hydrofluoric acid to regenerate phosphoric acid at the liquid storing section;
• and
• a phosphoric acid recovery section which is configured to return regenerated phosphoric acid to the liquid etchant to be used at said etching treatment section.