Electrical Characteristics of Low-Temperature Polycrystalline Silicon Complementary Metal-Oxide-Semiconductor Thin-Film Transistors with Six-Step Photomask Structure

We propose two types of six-step photomask, complementary metal-oxide-semiconductor (CMOS), thin-film transistor (TFT) PCT device structures in order to simplify their fabrication process compared with that of conventional, low-temperature, polycrystalline silicon (LTPS) CMOS TFT devices. The initial charge transfer characteristics of both types of six-step PCT are equivalent to those of the conventional nine-step PCT. Both types of six-step PCT are comparable to the conventional nine-step mask lightly doped drain (LDD) device in terms of the dc device lifetime of over 10 years at V-ds = 5 V for line inversion driving, which is the normally recognized duration time for semiconducting devices. (C) 2011 The Japan Society of Applied Physics