High-performance nonhydrogenated nickel-induced laterally crystallized P-channel poly-Si TFTs

• Published in: IEEE electron device letters Vol. 26; no. 12; pp. 900 - 902
• Main Authors: Lee, Y., Sanghoon Bae, Fonash, S.J.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.12.2005; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Active matrix organic light emitting diodes; Applied sciences; Channels; Crystallization; Electronics; Exact sciences and technology; Fabrication; Flat panel displays; High performance; Nanotechnology; Nickel; nickel-induced lateral crystallization; Nucleation; poly-Si thin-film transistor (TFT); Seeds; Semiconductor devices; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Substrates; Thin film transistors; Threshold voltage; Transconductance; Transistors; Performance evaluation; Voltage threshold; High performance; Hole mobility; Polycrystal; Hydrogenation; Thin film; poly-Si thin-film transistor (TFT); p channel; p type semiconductor; nickel-induced lateral crystallization; Thin film transistor; Transconductance; Electrical characteristic
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2005.859625

High-performance nickel-induced laterally crystallized (NILC) p-channel poly-Si thin-film transistors (TFTs) have been fabricated without hydrogenation. Two different thickness of Ni seed layers are selected to make high-performance p-type TFTs. A very thin seed layer (e.g., 5 /spl Aring/) leads to marginally better performance in terms of transconductance (Gm) and threshold voltage (V/sub th/) than the case of a 60 /spl Aring/ Ni seed layer. However, the p-type poly-Si TFTs crystallized by the very thin Ni seeding result in more variation in both V/sub th/ and G/sub m/ from transistor to transistor. It is believed that differences in the number of laterally grown polycrystalline grains along the channel cause the variation seen between 5 /spl Aring/ NILC TFTs compared to 60-/spl Aring/ NILC TFTs. The 60 /spl Aring/ NILC nonhydrogenated TFTs show consistent high performance, i.e., typical electrical characteristics have a linear field-effect hole mobility of 156 cm 2 /V-S, subthreshold swing of 0.16 V/dec, V/sub th/ of -2.2 V, on-off ratio of >10/sup 8/, and off-current of <1×10/sup -14/ A/μm when V/sub d/ equals -0.1 V.