{'fraction_non_alphanumeric': 0.02049469964664311, 'fraction_numerical': 0.005653710247349823, 'mean_word_length': 5.12987012987013, '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}}
Field-induced and photon-induced CD degradation in transmission reticles: a comparative review

Abstract. The progressive degradation of transmission reticles used in semiconductor production occurs via several mechanisms, the most prevalent being haze formation in 193 nm lithography. A less frequently observed yet more significant problem involves the migration of the chrome from the features in chrome-on-glass (COG) reticles onto the clear areas. All these critical dimension degradation mechanisms can result in yield loss but only the effect of haze can be corrected by cleaning the reticle. Chrome migration is caused by exposure to 193 nm UV and electric field. To differentiate between the two causes, different acronyms are used: here, PIM for photon-induced migration, and EFM for electric field-induced migration. The characteristics of both mechanisms are described and compared. A common explanation is proposed for PIM and EFM type 1, whereas EFM type 2 involves a physical process that is not present in PIM. These types of damage have only been observed in COG reticles to date, but the physical processes causing them are common to all materials. It is, therefore, concluded that ensuring the prevention of these progressive forms of reticle damage in all types of transmission reticle requires both the elimination of humidity and the exclusion of electric field from the reticle’s environment.