Characterization was performed on 60 nm +/3 nm films of atomic layer deposition (ALD) hafnium dioxide (HfO2) and aluminum oxide (Al2O3), and plasma-enhanced chemical vapor deposition (PECVD) silicon nitride (Si3N4) as MIM capacitor dielectric for GaAs HBT technology. The capacitance density of MIM capacitor with ALD HfO2 (2.73 fF/m 2 ) and Al2O3 (1.55 fF/m 2 ) is significantly higher than tha...

Obtaining a subthreshold swing (SS) below the thermionic limit of 60 mV dec-1 by exploiting the negative-capacitance (NC) effect in ferroelectric (FE) materials is a novel effective technique to allow the reduction of the supply voltage and power consumption in field effect transistors (FETs). At the same time, two-dimensional layered semiconductors, such as molybdenum disulfide (MoS2), have be...

Characterization was performed on the application of atomic layer deposition (ALD) of hafnium dioxide (HfO2) and aluminum oxide (Al2O3), and plasma-enhanced chemical vapor deposition (PECVD) of silicon nitride (Si3N4) as metal–insulator–metal (MIM) capacitor dielectric for GaAs heterojunction bipolar transistor (HBT) technology. The results show that the MIM capacitor with 62 nm of ALD HfO2 res...

The downscaling of the capacitance equivalent oxide thickness (CET) of a gate dielectric film with a high dielectric constant, such as atomic layer deposited (ALD) HfO2, is a fundamental challenge in achieving high-performance graphene-based transistors with a low gate leakage current. Here, we assess the application of various surface modification methods on monolayer graphene sheets grown by ...

The dielectric breakdown property of ultrathin 2.5 and 5.0 nm hafnium oxide (HfO2) gate dielectric layers with metal nitride (TaN) gate electrodes for metal oxide semiconductor (MOS) structure has been investigated. Reliability studies were performed with constant voltage stressing to verify the processing condition effects (film thicknesses and post metal annealing temperatures) on times to br...

The Ti/HfO2 interface plays a major role for resistance switching performances. However, clear interface engineering strategies to achieve reliable and reproducible switching have been poorly investigated. For this purpose, we present a comprehensive study of the Ti/HfO2 interface by a combined experimental-theoretical approach. Based on the use of oxygen-isotope marked Hf*O2, the oxygen scaven...

We have demonstrated a flexible resistive random access memory unit with trilayer structure by atomic layer deposition (ALD). The device unit is composed of Al2O3/HfO2/Al2O3-based functional stacks on TiN-coated Si substrate. The cross-sectional HRTEM image and XPS depth profile of Al2O3/HfO2/Al2O3 on TiN-coated Si confirm the existence of interfacial layers between trilayer structures of Al2O3...

Hafnia (HfO2) hollow nanofibers (HNs) were synthesized by atomic layer deposition (ALD) using electrospun nylon 6,6 nanofibers as templates. HfO2 layers were deposited on polymeric nanofibers at 200 C by alternating reactant exposures of tetrakis(dimethylamido)hafnium and water. Polymeric nanofiber templates were subsequently removed by an ex situ calcination process at 500 C under air ambient....

Based on micro-Raman spectroscopy (μRS) and X-ray photoelectron spectroscopy (XPS), we study the structural damage incurred in monolayer (1L) and few-layer (FL) graphene subjected to atomic-layer deposition of HfO2 and Al2O3 upon different oxygen plasma power levels. We evaluate the damage level and the influence of the HfO2 thickness on graphene. The results indicate that in the case of Al2O3/...

In this letter, we have investigated the physical and electrical characteristics of atomic layer deposition of HfO2 on GaAs substrates. X-ray photoelectron spectroscopy XPS analysis revealed no significant reduction of arsenic oxides upon deposition of HfO2 on GaAs using tetrakis dimethyl-amino hafnium Hf NMe2 4 as the metallic precursor. However, XPS confirmed the absence of arsenic oxides at ...