Reduced Trap-State Density of Ni-Silicide Seed-Induced Crystallized Poly-Si TFTs by Gettering

• Published in: IEEE electron device letters Vol. 33; no. 8; pp. 1141 - 1143
• Main Authors: Byun, Chang Woo, Son, Se Wan, Lee, Yong Woo, Joo, Seung Ki
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.08.2012; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Crystallization; Electronics; Exact sciences and technology; Gettering; Nickel; Polycrystalline silicon (poly-Si); Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; silicide seed-induced crystallization (SIC); silicides; Silicon; Silicon carbide; Thin film transistors; thin-film transistors (TFTs); Transistors; Interfacial layer; Interlayers; Polycrystalline silicon (poly-Si); Impurity; Polycrystal; Active layer; Nickel silicide; Gettering; IV-VI compound; thin-film transistors (TFTs); silicide seed-induced crystallization (SIC); silicides; Silicon carbide; Disruptive voltage; Silicon oxides; Leakage current; Silicon; Thin film transistor; On off effect
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2012.2200093

Polycrystalline silicon thin-film transistors (TFTs) fabricated by seed-induced crystallization (SIC) have large leakage currents due to defects that consist of Ni impurities. Here, we describe a novel method of gettering to remove Ni impurities using a Si gettering layer that is separated from the active layer by a chemical SiO 2 etch stop interlayer formed by dipping into H 2 SO 4 . The leakage current, the on/off ratio, and a channel breakdown voltage were greatly improved. These results were explained by lowered trap-state density in the channel.