Ambipolar operation of progressively designed symmetric bidirectional transistors fabricated using single-channel vertical transistor and electrochemically prepared copper oxide

In this study, a symmetric bidirectional transistors (SBT) is proposed. The device simultaneously implements the strong-inversion and accumulation mechanisms of a metal-oxide semiconductor field-effect transistor and TFT, respectively, in different bias directions in a single-channel vertical transistor (V-Tr). This ideal SBT device is designed and fabricated by selecting appropriate materials exhibiting a narrow bandgap and intrinsic characteristics of Sb-doped p-type Cu2O, using a V-Tr to optimize the device structure for high-field-induced short-channel and ambipolar operation, and implementing facile electrochemical deposition for channel and plasma channel treatments. To adopt artificial conductivity control for producing the transporting path of minority electron carriers, the patterned-channel-layer sidewall is locally treated using oxygen plasma, thereby suppressing the minority-carrier self-compensation. The SBT device exhibits an excellent on-current (i.e., symmetric accumulation and strong inversion modes in the p- and n-type channel regions, respectively) and excellent midregion off-current, similar to those of ideal ambipolar transistors. Moreover, owing to multilevel signals and excellent inverter behaviors, the SBT device is suitable for application in complementary-metal-oxide-semiconductors and logic memories.

Automated summary

In this study, a symmetric bidirectional transistors (SBT) is proposed, which combines the mechanisms of metal-oxide semiconductor field-effect transistor and TFT in different bias directions. The SBT device shows excellent on-current and midregion off-current, similar to ideal ambipolar transistors. Due to its multilevel signals and inverter behaviors, the SBT device is suitable for use in complementary-metal-oxide-semiconductors and logic memories.