{'fraction_non_alphanumeric': 0.02165506573859242, 'fraction_numerical': 0.020108275328692964, 'mean_word_length': 5.075117370892019, '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}}
Sub-Micron Lithography At 248nm And 193nm Excimer Laser Wavelengths

A primary thrust of optical lithography is the use of shorter wavelengths of light in order to produce smaller geometries for VLSI device production. Excimer lasers have been identified as likely candidates to extend optical lithography into the 0.4-0.3 micron regime. This paper describes an excimer laser optical approach for the projection imaging of sub-micron geometries. An excimer laser-based imaging and ablation system is described in detail along with initial results obtained with resist materials. The optical system employs inter-changeable lenses, with varying numerical apertures, reduction ratios, and field sizes. The data presented shows how excimer laser energy at the 248nm and 193nm wavelengths can produce 0.4-0.5um resolution using direct photoablative decomposition of the resist layer. Attenuation of the beam allows the system to be used for conventional latent image exposure and wet development with deep UV resists. Small-field chrome-on-quartz reticles at 15x and 36x are used to project device structures, resolution patterns and alignment marks. SEM photos show the resolution capabilities across the effective field of the system. Patterns as small as 0.3um are resolvable using this system.