{'fraction_non_alphanumeric': 0.032534246575342464, 'fraction_numerical': 0.010273972602739725, 'mean_word_length': 5.05699481865285, '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}}
First-principles predictions of electronic structure change in plasma-damaged materials

The electronic structure change after plasma exposure in representative materials used in electronic devices — crystalline Si substrate and Si3N4 film — is investigated by a first-principles approach. We prepared the starting structures of Si, α-, and β-Si3N4 with various key species (Ar, Br, Cl, N, and O) in processing plasmas. We investigated the electron charge density distribution and density of state (DOS) with the interstitial species after optimizing the prepared initial structures. Model predictions showed that the interstitial species create the DOSs, and that the energy-band edge extends to the midgap. The creation of the DOSs was clearly found in the β-Si3N4 structure model, while no obvious creation was obtained in the α-Si3N4 structure. This creation of the DOSs is consistent with the current–voltage (I–V) characteristics of the damaged Si3N4 films presumably consisting of α- or β-Si3N4 local structure. The distortion of the I–V curves was considered to be attributed to the creation of the DOSs, which play a role as carrier trapping/detrapping sites.