Narrow Results

This paper presents quantum dot channel (QDC) Field Effect Transistors (FETs) which are configured as nonvolatile memories (NVMs) by incorporating cladded GeO_x-Ge quantum dots in the floating gates as well as the transport channels. The current flow and the threshold characteristics were significantly improved when the gate dielectric was changed from silicon dioxide (SiO₂) to hafnium aluminum oxide (HfAlO₂), and the control dielectric was changed from silicon nitride (Si₃N₄) to hafnium aluminum oxide (HfAlO₂). The device operations are explained by carrier transport in narrow energy mini-bands which are manifested in a quantum dot transport channel.

Recent advances in silicon technology have pushed the silicon properties to its theoretical limits. Therefore, wide band gap semiconductors, such as silicon carbide (SiC) and gallium nitride (GaN) have been considered as a replacement for silicon. The discovery of these wide band gap semiconductors have given the new generation power devices a magnificent prospect of surviving under high temperature and hostile environments. The primary focuses of this review are the properties of GaN, the alternative substrates that can be used to deposit GaN and the substitution of SiO₂ gate dielectric with high dielectric constant (k) film. The future perspectives of AlGaN/GaN heterostructures are also discussed, providing that these structures are able to further enhance the performance of high power devices.

In the present study, Ta/La₂O₃ films (La₂O₃ doped with Ta₂O₅) as a gate dielectric were prepared using a sol–gel method at low pressure. Ta/La₂O₃ film has some hopeful properties as a gate dielectric of logic device. The structure and morphology of Ta/La₂O₃ films were studied using X-ray diffraction (XRD), atomic force microscopy (AFM) and scanning electron microscopy (SEM). Electrical properties of films were performed using capacitance–voltage (C–V) and current density-voltage (J–V) measurements. The optical bandgap of samples was studied by UV-visible optical absorbance measurement. The optical bandgap, E_opt, is determined from the absorbance spectra. The obtained results show that Ta/La₂O₃ film as a good gate dielectric has amorphous structure, good thermal stability, high dielectric constant (≈ 25), low leakage current and wide bandgap (≈ 4.7 eV).

This paper presents quantum dot channel (QDC) Field Effect Transistors (FETs) which are configured as nonvolatile memories (NVMs) by incorporating cladded GeO_x-Ge quantum dots in the floating gates as well as the transport channels. The current flow and the threshold characteristics were significantly improved when the gate dielectric was changed from silicon dioxide (SiO₂) to hafnium aluminum oxide (HfAlO₂), and the control dielectric was changed from silicon nitride (Si₃N₄) to hafnium aluminum oxide (HfAlO₂). The device operations are explained by carrier transport in narrow energy mini-bands which are manifested in a quantum dot transport channel.