Patent ID: 6881267

Claim:
A photoresist supply apparatus comprising: a photoresist bottle for containing a photoresist; a trap tank for storing the photoresist supplied from the photoresist bottle via a first photoresist supply line; a lower photoresist sensor and an upper photoresist sensor respectively installed near a bottom and a top of the trap tank to detect the photoresist in the trap tank; a drain line connected to an upper side of the trap tank to release air; a photoresist-blocking valve installed at the drain line, the photoresist-blocking valve structured to be opened to release air or closed to prevent a photoresist loss according to signals detected by the lower photoresist sensor and the upper photoresist sensor; and a photoresist pump for dispensing, onto a wafer, the photoresist supplied through a second photoresist supply line connected to a lower side of the trap tank.