{'fraction_non_alphanumeric': 0.03125, 'fraction_numerical': 0.013020833333333334, 'mean_word_length': 4.825757575757576, '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}}
Efficiency of Boron Gettering for Iron Impurities in p/p+ Epitaxial Silicon Wafers

The evaluation of B gettering for Fe impurities in p/p+ Si epitaxial wafers was carried out, after intentional Fe contamination, by measuring the Fe concentration in the epitaxial layer using deep level transient spectroscopy (DLTS). As the surface [Fe] before diffusion was increased, [Fe] in epitaxial layer also increased. As B concentration in the p+ substrate was raised, B gettering efficiency became higher. On comparison of the experimental results with the segregation gettering model, it was concluded that B gettering for Fe does not occur at a high temperature such as 800° C or 1100° C. B gettering for Fe can be inferred to occur below 600° C during the cooling process.