Patent ID: 8647703
Filing Date: 2014-02-11
Classification: B05C,G03F

Abstract:
1. A method for coating a photoresist on a substrate, the method comprising: dispensing a photoresist on the substrate at a discharge unit of a nozzle while the nozzle is moved from one end portion of the substrate to the other end portion thereof; while moving the nozzle to dispense photoresist, diagonally radiating a first light from a light emitting unit disposed at a lower portion of a foreign substance barrier toward the substrate, the first light being reflected by the substrate and received by a light receiving unit without being affected by a foreign substance; determining a reference strength of a reflected portion of the first light received by the light receiving unit; diagonally radiating a second light from the light emitting unit toward the substrate, the second light being reflected by the substrate and received by the light receiving unit; determining whether the foreign substance exists on the substrate based on a comparison between the reference strength of the reflected portion of the first light and a strength of a reflected portion of the second light, wherein the foreign substance barrier is inclined by 1° to 85° from an upper surface of the substrate, wherein an interval between the discharge unit and the foreign substance barrier is 10 to 300 μm, and wherein the foreign substance barrier is disposed on a bottom surface of the nozzle.