ITO-channel ferroelectric-gate thin film transistor with large on-current

Excellent transistor operation with large on-current and nonvolatile memory function is demonstrated for ferroelectric-gate thin film transistors (TFTs) using indium-tin-oxide (ITO) as a channel material. (Bi,La)₄Ti₃O₁₂ (BLT) is used as a gate insulator to obtain TFTs with nonvolatile memory function and (Ba,Sr)TiO₃ (BST) is used to fabricate TFTs without the memory function. Large on-current is due to the large charge density induced by the ferroelectric gate insulator in spite of the low channel mobility. In addition, relatively low off current can be obtained because the thin ITO channel can be depleted completely by the ferroelectric polarization