Computerized Wavelength Stabilized 248.4 Nm Excimer Laser For Stepper

A single stage excimer laser for UV microlithography has been developed. It emits 2 Watt average power at about 248.4 nm with a bandwidth of 0.5 cm -1. A novel computer-controlled feedback circuitry provides for automatic stabilization of both average power and integrated bandwidth. In addition, a computer-controlled frequency stabilization unit makes that new laser ready for industrial use as light source in deep UV microlithography.