AVS 46th International Symposium
    Flat Panel Displays Topical Conference Tuesday Sessions
       Session FP+OE+EM-TuA

Invited Paper FP+OE+EM-TuA8
Excimer Laser Processing for a-Si and poly-Si Thin Film Transistors for Imager Applications

Tuesday, October 26, 1999, 4:20 pm, Room 604

Session: Thin Film Transistor Materials and Devices
Presenter: J.P. Lu, Xerox Palo Alto Research Center
Authors: J.P. Lu, Xerox Palo Alto Research Center
P. Mei, Xerox Palo Alto Research Center
R.T. Fulks, Xerox Palo Alto Research Center
J. Rahn, Xerox Palo Alto Research Center
J. Ho, Xerox Palo Alto Research Center
Y. Wang, Xerox Palo Alto Research Center
J.B. Boyce, Xerox Palo Alto Research Center
R.A. Street, Xerox Palo Alto Research Center
Correspondent: Click to Email
Pulsed Excimer-Laser Annealing (ELA) has become an important technology to produce high performance Thin Film Transistors (TFTs) for large area electronics. The application of these advanced TFTs in flat pannel displays@footnote 1@ and flat panel imagers for two-dimensional X-ray imaging have attracted much interest. TFTs made from laser crystallized poly-Si thin films with mobility higher than 100 cm@super 2@/Vs can be consistently achieved and are well suited for the integrated driver circuits. Recently, leakage currents as low as 2fA/µm at 5V for these poly-Si TFTs have been achieved and enable one to consider making flat panel imagers using a full poly-Si process. Laser doping@footnote 2@ or dopant activation is another important application of the ELA process. Using a laser doping process, we have fabricated a-Si TFTs with self-aligned poly-Si source/drain contacts. These new devices have reduced source/drain parasitic capacitance and their channel length can be easily scaled down without stringent lithography requirements. Excellent DC performance, such as low leakage current (0.02fA/µm), sharp turn on (0.44V/decade) and high mobility of a-Si TFTs are preserved. In addition, good AC performance of these self-aligned a-Si TFTs has been demonstrated in four phase dynamic shift registers operating at 250kHz. In this talk, these two areas will be reviewed along with a report on the current status in developing poly-Si TFTs and self-aligned a-Si TFTs using ELA process for flat panel imager applications. @FootnoteText@ @footnote 1@ J. G. Blake, M. C. King, J. D. Stevens III, and R. Young, Solid State Technology, p151, May 1997. @footnote 2@ P. Mei, G. B. Anderson, J. B. Boyce, D. K. Fork, and R. Lujan, Thin Film Transistor Technologies III, Electrochemical Soc. Proc., PV 96-23, p51 (1997).