Abstract: An active plate (2) for an active matrix display device (16), the active plate (2) comprising a substrate (4), a pixel area (6) and an adjacent drive circuit area (8). Both areas include polycrystalline silicon material formed by a process in which a metal is used to enhance the crystallization process (MIC poly-Si), but only the MIC poly-Si in the drive circuit area (8) is subjected to an irradiation process using an energy beam (10). TFTs are fabricated with MIC poly-Si which have leakage currents in the off state sufficiently low for them to be acceptable for use as switching elements in the pixel area of matrix display devices. As only the drive circuit area (8) need be irradiated to provide poly-Si having the desired mobility, the time taken by the irradiation process can be significantly reduced.

Abstract: A method of manufacturing an electronic device comprising a thin film transistor (42), comprises forming a hydrogen-containing layer (22) over a semiconductor layer (10;20), irradiating the hydrogen-containing layer so as to hydrogenate the semiconductor layer, and then forming electrodes (24;26,28) over the semiconductor layer. A short diffusion length and direct path is provided for the hydrogen thus allowing rapid hydrogenation of the semiconductor layer using relatively few, high-fluence laser pulses. The supporting substrate (12) is not heated significantly making the method particularly useful for TFTs on polymer substrates. Crystallisation and hydrogenation of the semiconductor layer can be executed in the same irradiation step.