Flat microwave-powered ultraviolet source.
A microwave-powered ultraviolet source capable of covering an area as large as a 150-mm Si wafer is developed. Fifteen low pressure mercury discharge lamps are arrayed in a flat microwave cavity. The Hg 254-nm irradiance on the surface 1 cm from the lamps is 120 mW/cm(2) at a microwave power of 1200 W. This UV source is used for photoresist removal. Low pressure cadmium lamps, which have the Cd 229-nm irradiance of 13.9 mW/cm(2) at 1 cm for a 500-W input, are also investigated.