Lambda Physik Ag

Alexander O Wiessner

Sergei V Govorkov

Rainer Paetzel

Gongxue Hua

Timur Misuryaev

Thomas Schmidt

Igor Bragin

Andriy N Knysh

The relative timing delay between channels of a discharge circuit can be adjusted through application of appropriate control voltages. A control voltage of relatively long duration and relatively small voltage, with respect to a common system pulse, can be applied to any channel in order to adjust the relative timing delay. This control voltage can be, for example, a magnetization pre-pulse voltage applied to an indictor for a channel in order to adjust a hold-off time. A synchronization control unit and feedback loop can be used to monitor the timing, such that the syncronization control unit can apply a control voltage when a delay change exceeds a timing adjustment threshold value, and can apply a pre-ionization voltage when the delay change is less than the adjustment threshold value. Using both a control voltage and a pre-ionization voltage provides for both coarse and fine adjustment of the delay.

MOPA excimer or molecular fluorine laser system with improved synchronization

The lifetime of optical components used in deep-UV (DUV) excimer laser systems, including systems in a MOPA configuration, can be increased by reducing the intensity of pulses incident upon these components. In one approach, an output pulse can be 'stretched' in order to reduce the peak power of the pulse. A pulse stretching component can be used, which can be mounted outside the laser enclosure with a horizontal beam path in order to provide a delay line with a minimum impact on the laser system footprint. The horizontal beam path also can minimize the number of optical components in the arm containing the high power beam. A beamsplitting prism can be used with the delay line to avoid the rapid degradation of coatings otherwise exposed to intense UV beams. The prism can expand the beam in the delay line in order to minimize beam intensity and losses due to reflection.

Master-oscillator power-amplifier (MOPA) excimer or molecular fluorine laser system with long optics lifetime

Pulse parameters of a gas discharge laser system can be optimized and controlled for precision applications such as microlithography. Important laser pulse parameters typically vary in the beginning of a pulse burst, and the directionality of the output beam typically varies throughout the burst. In order to improve the performance of the laser system, the variation at the beginning of a pulse burst can be eliminated by extending the pulse pattern and shuttering the output during periods of significant parameter variation. A fast shutter such as an acousto-optical modulator can be used to prevent output during the burst transition processes. Elements such as acousto-optical cells also can be used in combination with a fast position sensor to steer the direction of the output beam, in order to adjust for variations in the direction of the beam between pulses in a burst.

Master oscillator/power amplifier excimer laser system with pulse energy and pointing control

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Goettingen, Germany

Alexander O Wiessner