Low frequency noise in thin film transistors

Abstract

Works concerning low frequency noise in thin film transistors are reviewed and significant results reported. To offer relevant noise analysis, some considerations on the electrical conduction in thin film transistors are presented. Based on these considerations, models generally used to describe low frequency noise in thin film transistors are given. They stem from those developed for 1/f noise in metal-oxide-semiconductor field-effect transistors and they have been adapted to take into account the effects of the nonhomogeneous conducting channel. Amorphous silicon and polycrystalline silicon active thin film especially are considered. For these two kinds of materials, an analysis of the experimental noise measurements obtained by several authors is presented with their theoretical explanations. Results of investigations on the nonhomogeneous active film deduced from noise measurements are also reported. Finally, particular noise aspects in thin film transistors are studied such as the noise associated with access resistances in inverted staggered structures or the possibility to apply the BSIM (Berkeley short channel insulated gate field-effect transistors model) for 1/f noise modelling in thin film transistors.