An Investigation of Electrothermal Characteristics on Low-Temperature Polycrystalline-Silicon Thin-Film Transistors

In this paper, theoretical and experimental analyses have been performed to explore the electrothermal characteristics in low-temperature polycrystalline-silicon thin-film transistors (LTPS TFTs). A theoretical simulation reveals that electrothermal effects strongly influence the performance of LTPS TFTs, particularly under high-current conditions. Measurements show that, under extremely high currents, LTPS devices demonstrate an open-circuit behavior, while the behavior of devices based on single-crystalline silicon films using an SOI CMOS process results in a short-circuit model. In summary, both the simulation and measurements indicate that grain boundaries will degrade the electrothermal properties of the LTPS thin film and suppress reliability in TFT design.