Patent ID: 7107701

Claim:
A substrate drying apparatus comprising: a drying chamber including (i) an upper pure water tank-section in which substrates are to be immersed in pure water, and (ii) a lower pure water tank-section having a fixed bottom; an isopropyl alcohol supply device for supplying air or an inert gas, and gaseous or droplet-like isopropyl alcohol, into a space above a liquid level of the pure water when in said upper pure water tank-section; a mechanism for draining pure water from said upper pure water tank-section while preventing turbulence in the pure water, said mechanism including (i) a plate dividing an interior of said drying chamber into said upper pure water tank-section and said lower pure water tank-section such that said plate defines a bottom of said upper pure water tank-section, with an entire periphery of said plate being spaced from an inner surface of said drying chamber by a gap; (ii) a plate elevator for raising said plate relative to said drying chamber so as to drain pure water, on a liquid level side, from a liquid level or a vicinity of the liquid level of the pure water in said upper pure water tank-section by raising the substrates together with the pure water in which the substrates are immersed; and (iii) a pure water supply unit for supplying pure water into said lower pure water tank-section in an amount corresponding to an increase in volume of said lower pure water tank-section due to raising of said plate, so as to prevent turbulence in the pure water in said upper pure water tank-section due to inflow/outflow of pure water through said gap; and a control unit for controlling operation of said plate elevator and said pure water supply unit such that the pure water is supplied into said lower pure water tank-section in the amount corresponding to the increase in volume of said lower pure water tank-section due to the raising of said plate so as to prevent turbulence in the pure water in said upper pure water tank-section due to inflow/outflow of pure water through said gap, such that when the pure water and the substrates are raised relative to said drying chamber by raising said plate via said plate elevator, while preventing turbulence in the pure water in said upper pure water tank-section by supplying pure water into said lower pure water tank-section via said pure water supply unit, the pure water at the liquid level is drained, the substrates are exposed from the pure water above the liquid level in said upper pure water tank-section, and, at the same time, the pure water held on exposed surfaces of the substrates is replaced by the gaseous or droplet-like isopropyl alcohol supplied by the isopropyl alcohol supply device, and then the substrates can be dried by evaporating the isopropyl alcohol from the exposed surfaces of the substrates.