An Improved All-Solid-State Hybrid Energy Storage Pulse Circuit for Excimer Laser Power Supply

Excimer lasers, utilized in advanced semiconductor industries such as deep ultraviolet lithography, have been developed toward higher power outputs, which necessitates increased maximum repetition frequency and output voltage amplitude from their power supplies. This article proposes a hybrid energy storage method achieved by extending the IGBT turn-<sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> time in the voltage multiplication circuit. This method is primarily based on a commercially mature topology of the conventional power supply with minor revisions and uses fewer IGBTs, making the new power supply reliable and simple to control. The influence of the IGBT turn-<sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> time on the energy transfer characteristics of the voltage multiplication loop is studied through an experimental prototype and theoretical calculations. The results demonstrate that the hybrid energy storage circuit can operate in two improved modes: 1) voltage enhancement mode and 2) repetition frequency enhancement mode. For the first mode, this proposed power circuit significantly enhances the amplitude of the voltage pulse, with the effect strengthens as the IGBT turn-<sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> time increases. However, the duration of a single pulse increases in this mode, resulting in a reduction in the maximum repetition frequency. For the second mode in which the amplitude of the output voltage pulses is kept constant, the maximum repetition frequency can be increased from 3.4 kHz in the conventional circuit to at most 3.54 kHz in the newly proposed circuit, which is a slight increase of 4.1%. Theoretical calculations suggest that this frequency can be further improved by 18.4% under specific conditions.