摘要 |
A method of manufacturing a thin film transistor (TFT), comprises a photolithography step, wherein a photopolymer 7 is applied over a metalisation layer 6 and exposed to light through a photomask 8. The photomask 8 is a transparent substrate 9 with one surface partially covered to form transparent 12a, 12b, half-tone 11 and opaque 10a, 10b areas. In order to reduce diffraction effects, half-tone areas 11 are formed using a periodic pattern of opaque and transparent areas, e.g. a checkerboard, grid or parallel lines. The exposed photopolymer is removed, leaving an indented layer of photopolymer 7 and partially uncovering the metalisation layer 6. Following etching of the uncovered metalisation layer 6, the remaining photopolymer layer 7 may be thinned, exposing further portions of the metalisation layer 6 for etching. The photomask 8 may be configured so that a half-tone area is used to define a channel and opaque areas correspond to the positions of source and drain terminals. |