Self-Aligned Amorphous Silicon Thin-Film Transistors Fabricated on Clear Plastic at 300 $^{circ}hbox{C}$

摘要

We fabricated back-channel-cut and back-channelpassivated hydrogenated amorphous silicon (a-Si:H) thin-film transistors (TFTs) on clear-plastic (CP) foil substrates using a silicon nitride $(hbox{SiN}_{x})$ deposition temperature of 300 $^{circ} hbox{C}$. The TFTs were fabricated on CP and are as stable under high gate bias as TFTs made on glass substrates. A self-alignment technique was developed to align the channel passivation, the a-Si:H island, and the source/drain (S/D) terminals to the gate. Self-alignment allowed us to fabricate discrete TFTs across $hbox{7} times hbox{7} hbox{cm}^{2}$ of a free-standing sheet of CP foil to reduce the TFT channel length $L$ to 3 $muhbox{m}$ and reduce the S/D overlap with the gate $L_{rm SD}$ to $sim!! hbox{1} muhbox{m}$. To test the self-alignment techniques, we fabricated ring oscillators on the CP substrates. These results show that it is possible to fabricate state-of-the-art self-aligned a-Si:H TFTs and TFT circuits on plastic substrates.