Manufacture of active matrix display devices

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 crystallisation 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