Suppression of Self-Heating in Low-Temperature Polycrystalline Silicon Thin-Film Transitors

We investigated the structure of low-temperature polycrystalline silicon (poly-Si) thin-film transistors (TFTs) focusing on their immunity against thermal degradation. Their operating temperature was simply dependent on input power and independent of bias voltage, such as drain or gate bias voltage. As for the structures, self-heating was suppressed by increasing the number of splitting gates and the interval between poly-Si layers owing to effective heat diffusion along the gate width. For multi gate-type TFTs, increasing the number of splitting gates was effective in suppressing self-heating; however, increasing the interval between gates was not effective. We proposed a new offset-type structure. Using this new structure, we were able to demonstrate the effective suppression of degradation caused by self-heating.