| 摘要 |
PURPOSE:To provide a circulation bath for a chemical treatment capable of preventing adhesion of extraneous matter to an object under treatment by using means for blowing gas to a central surface of the liquid. CONSTITUTION:A resist-coated silicon wafer 6, which has been developed, is held by a carrier and immersed in a bath containing a chemical solution 2 for etching photoresist. The solution in the bath 1 is circulated through a recycling device and an inlet port 3. There is provided a blower means 7 having a control valve 7b and a nozzle 7c. While the valve is closed, the solution 2 is stagnant in the central part of the surface, and extraneous matter 8 floats. When the control valve 7b is adjusted, the flow of nitrogen gas is increased gradually and directed against the central part 1 of the surface of the solution 2 through the nozzle 7c. At a certain flow rate, radial flows of the solution 2 from the center are created, and they join peripheral flows overflowing into a section 5. Therefore, the extraneous matter will not adhere to the wafer being pulled up. Further, the central portion of the solution, containing a lot of extraneous matter, is not allowed to stagnate, resulting in efficient operation of the circulation bath. |
