Nonvolatile Memory (NVM) Operation of Tunnel Field-Effect Transistor (TFET) Using Ferroelectric HfO2 Sidewall.

In this paper, we propose a new type of nonvolatile memory (NVM) device based on a tunnel field-effect transistor (TFETs) with Ferroelectric HfO2 sidewall. By simply utilizing the ferroelectricity of orthorhombic HfO2 and conventional sidewall spacer technique, TFET can operate as a NVM device. The polarized charges in the ferroelectric HfO2 spacer induced by program/erase pulse modulate the tunneling barrier between the source and channel; thus, change the threshold voltage (Vt) of TFET. The proposed NVM TFET has lower subthreshold swing (SS) and higher on/off ratio than conventional NVM TFETs while maintaining equivalent program/erase efficiency. Further-more, we also investigate the optimal HfO2 sidewall formation conditions to achieve higher NVM performances.