Low temperature silicides for thin film transistor applications in active-matrix liquid crystal display technology

Thermally and chemically stable, low resistivity, and low temperature metallization is required in the driver circuitry and pixel array of active-matrix liquid crystal displays. Thin, stable scan and data lines allow flexibility in driver circuitry and panel array design. As data rates increase, the parasitic resistance of the thin-film transistors in the drivers must be minimized. Furthermore, for proper operation of both the display drivers and the active-matrix array, a reliable contact to the source and drain of the devices is required. Tungsten, cobalt, and nickel are studied for their ability to form silicides for use in active-matrix display drivers and switching elements. Thin films of tungsten, cobalt, and nickel were magnetron sputtered onto crystalline and amorphous silicon, then in-situ, in-vacuo annealed under a quartz-lamp heater. After metal etching, the sheet resistance of the resulting films was measured. The effect of surface preparation before metal deposition on the resulting film and its sheet resistance is also examined.