Photoresist supply system with air venting
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsJen Song Liu, Bii Juno Chang, Jen Shang Fang, Hao Wei Chang
Life of this patent
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Abstract
A system for pumping resist to a wafer coating machine includes a line that returns a selected proportion of the resist entering the resist pump to the resist supply tank. The return line to the tank is connected to the pump outlet at a higher point than the pump outlet to the wafer coating machine, and the resist that is returned to the tank carries substantially all of the bubbles that are carried in the resist entering the tank. The bubbles are removed from the resist in the tank and the resist can be used normally.
Claims3
A method for supplying resist to an apparatus for applying the resist to a semiconductor wafer comprising,
- providing a tank for holding the resist and a pump for transferring resist from the tank to the resist applying apparatus, the pump having an inlet from the tank and an outlet to the apparatus for applying the resist, the resist being subject to contamination by bubbles, and
- venting resist from an outlet position on the pump that is higher than an outlet position for supplying resist to the resist applying apparatus to the tank at a tank position above the resist held in the tank, the resist being vented to the tank containing bubbles,
- and removing bubbles from the resist in the tank comprising applying a vacuum to the tank, and wherein the step of venting resist from the pump outlet to the tank allows bubbles to be released as the returning resist falls to the level of the resist in the tank,
- whereby resist vented from the pump outlet and returned to the tank is available for transfer to the resist applying apparatus.
Dependencies are inferred from the claim text.