{'fraction_non_alphanumeric': 0.030927835051546393, 'fraction_numerical': 0.020618556701030927, 'mean_word_length': 4.633928571428571, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Ultrahigh-repetition-rate ArF excimer laser with long pulse duration for 193-nm lithography

High-repetition-rate ArF excimer lasers are needed to enable high throughput and energy-dose stability in 193-nm scanner systems. Last year we described a 4-kHz ArF excimer laser with long pulse duration, which can narrow the spectral bandwidth by increasing the number of round trips and reduce optical damage from low-peak power. The design of the 4-kHz ArF excimer laser has been improved for mass production. Operating rates exceeding 4 kHz are needed to optimize lasers for next-generation technologies that can enable high NA and the development of high-throughput scanners. We have analyzed the possibilities of achieving repetition rates higher than 4 kHz. The discharge width was reduced by about 25 % with a variation of the electric field at the discharge section, and the gas flow and gas-mixture conditions were improved. As a result, we obtained the following performance characteristics: 42-W average power, 3.5 % pulse-to-pulse energy stability of sigma, and a 44-ns integral-square pulse width at 6 kHz with a bandwidth of below 0.45 pm in FWHM. We concluded that developing 6-kHz ArF excimer lasers for next-generation 193-nm lithography is feasible.