{'fraction_non_alphanumeric': 0.02109181141439206, 'fraction_numerical': 0.008684863523573201, 'mean_word_length': 5.637860082304527, '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}}
Reduction of metal linewidths through a combination of low-temperature and ultrasonic development of poly(methylmethacrylate) using electron-beam lithography

As device sizes continue to approach nanoscale dimensions, it is essential to develop methodologies that enable more accurate and reliable fabrication of sub-10nm linewidths for devices. In this paper, we present a strategy of combining low-temperature and ultrasonic processing to produce uniform sub-10nm metal lines using electron beam lithography. Specifically, a cold development process that increases both the initial and critical electron beam doses, and thus further improves the tunability, during ultrasonic development was employed. The use of ultrasonic development in combination with cold development caused a larger decrease in the critical dose than the decrease of the initial dose, which results in a resist contrast that is higher than when ultrasonic or cold development are used alone. The increase in the contrast helps to achieve finer line patterns. Additionally, the increase of contrast and critical dosage results in higher pattern uniformity and reproducibility. Using this strategy, metal lift-off patterns with an average linewidth of less than 10nm were achieved using a conventional beam voltage of 15kV, providing narrower average linewidths than are obtained without this strategy (typically 20-30 nm). Thus, this methodology provides a way to reliably fabricate sub- 10nm uniform patterns for the development of the next generation of nanoscale electronic devices, interconnects, and, ultimately, integrated circuits.