Process for manufacture of flat panel liquid crystal display using direct laser etch

Abstract

A direct laser ablation process is disclosed for forming thin film transistors on liquid crystal matrix for enabling typically color presentation from a flat panel display. The thin film transistor is of the type having an active matrix addressing scheme wherein a capacitor when charged turns on and maintains in the "on" state a field effect transistor to permit passage of light through a liquid crystal display. All patterning of the display is done either by utilizing deposition, direct ablation of an etch block followed by etching, or more preferably deposition followed by direct laser ablation. In the preferred embodiment, aluminum channels are made by deposition followed by a direct laser ablation. Anodizing follows with deposition of a silicon-nitrogen layer. With respect to the capacitor, indium tin oxide is deposited to complete a matrix capable of selectively strobing and charging the capacitor for each matrix element. Local photo deposition of amorphous silicon in a gas carrier occurs under focused laser light occurs followed by laser annealing to form the required polycrystalline state. A chrome interface layer is sputter coated followed by direct laser etch. An aluminum cap is added for providing power conduction to the complete NPN transistor. Utilizing the precision of direct laser processing, a display can be fabricated with acceptable yield due to the reduced number of process steps. The remainder of the LCD display is conventional including filter material placement and panel assembly.

Dependencies are inferred from the claim text.