Electrical Instability of the a-Si:H TFTs Fabricated by Maskless Laser-Write Lithography on a Spherical Surface

We fabricated and characterized hydrogenated amorphous silicon (a-Si:H) thin-film transistors (TFTs) with a channel length of 10 on both spherical and flat surfaces using maskless laser-write lithography (LWL). In addition to the electrical performance, the threshold voltage shift of the a-Si:H TFT under bias-temperature stress is investigated and discussed in comparison to a device fabricated on a flat surface. The obtained results show that the a-Si:H TFTs fabricated by LWL method on a curved surface are suitable for pixel switches and circuits, which are needed to realize image sensor arrays and/or displays on a nonplanar surface.