Patent ID: 6635844
Filing Date: 2003-10-21
Classification: B08B,B23K

Abstract:
A stepper system having an on-line wafer chuck laser cleaning apparatus, the stepper system comprising:an excimer laser generation module for generating a pulse laser with a predetermined wavelength; a wafer stage capable of horizontally moving along x-y directions vertically moving along z direction; a control system used to control displacements of the wafer stage along the x-y directions and the z direction; a wafer chuck, for holding a wafer-to-be-exposed by vacuuming, fixed on the wafer stage, the wafer chuck having a top surface capable of being contaminated by organic material; a laser beam delivery system for guiding the pulse laser either to a contaminated top surface of the wafer chuck at a predetermined incident angle to decompose organic material thereon by the pulse laser, or to the wafer-to-be-exposed held on the wafer chuck to transfer pattern on a mask to the wafer-to-be-exposed; a projection lens system for focusing the pulse laser to the wafer-to-be-exposed; a laminar flow chamber located at one end of the laser beam delivery system and used to isolate the wafer chuck during the wafer chuck cleaning, the laminar flow chamber having an opening at a bottom, a gas inlet, and an exhaust; and an inert gas supply connected with the gas inlet of the laminar flow chamber for providing an inert gas flow, wherein the inert gas flow is in a laminar regime within the laminar flow chamber facilitating the removal of the decomposed organic material from the top surface of the wafer chuck; wherein the organic matter contaminated top surface of the wafer chuck is globally or locally cleaned by the control of the control system-controlled wafer stage.