{'fraction_non_alphanumeric': 0.03206997084548105, 'fraction_numerical': 0.012633624878522837, 'mean_word_length': 5.319018404907975, '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}}
Spectroscopic Ellipsometry Study of Si Surfaces Modified by Low-Energy Ar+-Ion Irradiation

Spectroscopic ellipsometry (SE) measurements are carried out to study structural modification of Si surfaces induced by low-energy Ar+-ion irradiation. The Ar+ ions are irradiated on Si(100) substrates at acceleration voltages between -150 and 0 V and substrate temperatures between 20 and 410?C. The SE data clearly suggest that the Ar+-ion irradiation modifies Si surfaces depending upon Ar+-ion energy and substrate temperature. An effective medium approximation (EMA) and a linear regression analysis (LRA) suggest that the surface layers modified with Ar+ ions at higher substrate temperatures consist of volume fractions of voids, crystalline and amorphous Si and those modified at lower substrate temperatures consist of volume fractions of SiO2, amorphous Si and voids. SE has thus proven to be an easy, fast and nondestructive technique that can be used to assess important structural parameters of Ar+-ion-modified Si surfaces.