Low-Frequency Noise Characteristics in HfO-Based Metal-Ferroelectric-Metal Capacitors.

The transport mechanism of HfO-based metal-ferroelectric-metal (MFM) capacitors was investigated using low-frequency noise (LFN) measurements for the first time. The current-voltage measurement results revealed that the leakage behavior of the fabricated MFM capacitor was caused by the trap-related Poole-Frenkel transport mechanism, which was confirmed by the LFN measurements. The current noise power spectral densities () obtained from the LFN measurements followed 1/ noise shapes and exhibited a constant electric field () × / noise behavior.

Normally-off β-GaO MOSFET with an Epitaxial Drift Layer.

A normally-off β-GaO metal-oxide-semiconductor field-effect transistor (MOSFET) is proposed using a technology computer-aided design (TCAD) device simulation, which employs an epitaxial drift layer grown on an -type low-doped body layer. The low-doped body layer under the MOS gate enabled normally-off operation, whereas the epitaxial drift layer determined the on-resistance and breakdown characteristics. The effects of the doping concentration of each layer and thickness of the drift channel layer on the device characteristics were investigated to design a device with a breakdown voltage of 1 kV.

Temperature- and Frequency-Dependent Ferroelectric Characteristics of Metal-Ferroelectric-Metal Capacitors with Atomic-Layer-Deposited Undoped HfO Films.

In this study, we evaluated the temperature- and frequency-dependent ferroelectric characteristics of TiN/undoped HfO/TiN metal-ferroelectric-metal (MFM) capacitors in which an undoped HfO film was deposited through atomic layer deposition (ALD). Successful ferroelectric characteristics were achieved after postdeposition annealing at 650 °C, which exhibited a remanent polarization of 8 μC/cm and a coercive electric field of 1.6 MV/cm at 25 °C (room temperature).