Investigation of the electromechanical stability of low temperature polycrystalline silicon thin-film transistors governed by types of stress

Abstract

The electromechanical stability of low temperature polycrystalline silicon thin-film transistors embedded on plastic film was investigated as a function of type of stress and cyclic bending. The results show these devices to have reliable electromechanical integrity against mechanical strain at a bending radius of a few millimeters under compressive stress on the inner bending surface. By contrast, after being subjected to tensile stress on the outward bending surface, the devices show significant electrical failure under the induced strain. The onset of strain fracture also closely corresponds to the electrical failure of the device when exposed to tensile stress. The deformation kinetics caused by stress accumulation were investigated in multiple films with regard to a flexible backplane; these results reveal that mechanical integrity in reliable device design could be effectively provided by controlling the types of stress and could be put into practical use in flexible electronics applications.