Process for producing an active matrix display screen with gate resistance

Claim 1

Process for producing an active matrix display screen, this process consisting in making a lower wall (10) carrying first capacitor plates (22) and thin-film transistors (20), conductive addressing lines (14) and columns (12), and an upper wall (24) coated with a counterelectrode (26) forming a second capacitor plate, this process being characterized by the fact that, to make the lower wall (10), the following operations are performed: depositing on an insulating substrate (50) of a layer (52) of a first transparent conductive material, optionally surmounted by a layer (54) of n doped amorphous silicon, a first photoengraving to form blocks (51) forming one of the capacitor plates of the future capacacitors and columns (55), this first photoengraving allowing to subsist also beside each block two parallel segments (53, 57), one segment (57) constituting the future drain of the transistor and connected to the adjacent column (55) and the other segment (53) constituting the future source of the transistor and connected to the block in question (51), depositing of a stack consisting of a layer (60) of hydrogenated amorphous silicon, a layer (62) of a first insulating material, a layer (63) of n + highly doped amorphous silicon constituting the future gate resistance, a layer (64) of a second insulating material, a layer (65) of a first metal, a second photoengraving applied to the preceding stack to free the blocks (51) but to allow this stack to subsist along lines inserted between the blocks, these lines overlapping the two parallel segments (53, 57) and to allow this stack to subsist on the columns, except at the place where these columns intersect the lines, this second photoengraving being only partial between the two segments and causing the layer of the first metal (65) of the second insulating material (64) to disappear and causing layer (63) of highly doped amorphous silicon, constituting the future gate resistance, to appear, depositing of a layer of a second metal (66), a third photoengraving applied to this layer of second metal (66) to allow the lines to subsist, which makes the contact between layer (63) of highly doped amorphous silicon and the lines, this third photoengraving also allowing the second metal to subsist on what remains of the first metal on the columns.