초록 ▼

Nitrogen gas is blown into a developing solution tank, and a developing solution is supplied through a supply nozzle to the surface of a wafer, through a filter unit or the like, with the pressure. The filter unit has a ring-shaped flow path flowing from down upward, an impurity filter provided on t

Nitrogen gas is blown into a developing solution tank, and a developing solution is supplied through a supply nozzle to the surface of a wafer, through a filter unit or the like, with the pressure. The filter unit has a ring-shaped flow path flowing from down upward, an impurity filter provided on the inside thereof, an exhaust passage connected to an uppermost portion of the flow path, and a bubble filter composed of, for example, a hollow fiber membrane, which is provided to block a part of the exhaust passage and has the property of transmitting gas without transmitting liquid. The dissolved nitrogen contained in the developing solution is changed to bubbles by vaporizing in the flow path, and only the bubbles can be removed from the developing solution since the aforesaid bubble filter selectively transmits these bubbles whereby the amount of the developing solution can be saved. Accordingly, it is possible to remove the bubbles contained in a treatment solution while reducing consumption of the treatment solution.

대표청구항 ▼

1. A filter unit for removing impurities and bubbles from a treatment solution comprising:a flow path for flowing said treatment solution; an impurity filter provided in said flow path, for removing impurities from said treatment solution; an exhaust passage for exhausting gas from said flow path to

1. A filter unit for removing impurities and bubbles from a treatment solution comprising:a flow path for flowing said treatment solution; an impurity filter provided in said flow path, for removing impurities from said treatment solution; an exhaust passage for exhausting gas from said flow path to outside thereof, said exhaust passage connected to an adjacent part of said flow path to said impurity filter on an upper stream side of said impurity filter; and a bubble filter provided in an adjacent part of said exhaust passage to said flow path, for letting the gas pass therethrough and preventing the treatment solution from passing therethrough.