ULTRAHIGH PRESSURE MERCURY LAMP FIRING DEVICE FOR EXPOSING SEMICONDUCTOR WAFER MATERIAL

摘要

PURPOSE:To enable to immediately reopen an exposing process after a power interruption is momentarily recovered by suppressing power supplied to an ultrahigh pressure mercury lamp to a small value by energy stored in a capacitor for a power interruption period firing lamp when a commercial AC power source is momentarily interrupted during the exposing process. CONSTITUTION:A contact S1 is closed and a contact S2 is opened by a momentary power interruption detector 271 during a period that a commercial AC power source E is normal during an exposing process, the output of a comparator COM becomes an output according to a set power reference voltage source VH, and controlled to be fed back so that the power supplied to an ultrahigh pressure mercury lamp 4 coincides with the set power W0. If a momentary power interruption of the power source E occurs during the exposing process, the contact S1 is opened and the contact S2 is closed by the detector 271, the output of the COM becomes an output according to a momentary power interruption reference power source VL, and momentary power interruption power W1 is supplied to the lamp 4. Since W1 is smaller than W0 and the lamp 4 is powered to continue discharging, the exposing process can be immediately started after the power interruption is recovered.