Abstract: Improvement of Hf-based high-k gate dielectrics by incorporating Ta and La in HfO2 are investigated systematically. The main issues of pure HfO2 gate dielectric, including low crystallization temperature, channel mobility degradation, and bias temperature instability (BTI) degradation, can be effectively improved in HfTaO and HfLaO. Particularly, HfLaO with appropriate metal gate mate...

High-temperature phases of hafnium dioxide have exceptionally high dielectric constants and large bandgaps, but quenching them to room temperature remains a challenge. Scaling the bulk form to nanocrystals, while successful in stabilizing the tetragonal phase of isomorphous ZrO2, has produced nanorods with a twinned version of the room temperature monoclinic phase in HfO2. Here we use in situ h...

We combine nanolaminate bilayer insulator tunnel barriers (Al2O3/HfO2, HfO2/Al2O3, Al2O3/ZrO2) deposited via atomic layer deposition (ALD) with asymmetric work function metal electrodes to produce MIIM diodes with enhanced I-V asymmetry and non-linearity. We show that the improvements in MIIM devices are due to step tunneling rather than resonant tunneling. We also investigate conduction proces...

Crossbar resistive switching devices down to 40 × 40 nm(2) in size comprising 3-nm-thick HfO2 layers are forming-free and exhibit up to 10(5) switching cycles. Four-nanometer-thick devices display the ability of gradual switching in both directions, thus emulating long-term potentiation/depression properties akin to biological synapses. Both forming-free and gradual switching properties are mod...

To extend the use of CMOS technology beyond 14 nm node technology, new device materials are required that can enhance the performance of MOSFETs. The use of high-k materials in double gate (DG) MOSFET can triumph over the problem of power dissipation and leakage current. In this paper, we investigated various high-k dielectrics as the gate oxides in a 12 nm SOI FinFET and the performance potent...

The electrical characteristics of germanium p-metal– oxide–semiconductor (p-MOS) capacitor and p-MOS field-effect transistor (FET) with a stack gate dielectric of HfO2/TaOxNy are investigated. Experimental results show that MOS devices exhibit much lower gate leakage current than MOS devices with only HfO2 as gate dielectric, good interface properties, good transistor characteristics, and about...

Nanostructured Si as the high efficiency photoelectrode material is hard to keep stable in aqueous for water splitting. Capping a passivation layer on the surface of Si is an effective way of protecting from oxidation. However, it is still not clear in the different mechanisms and effects between insulating oxide materials and oxide semiconductor materials as passivation layers. Here, we compar...

Realistic models of amorphous ZrO2 are generated in a “melt-and-quench” fashion using ab initio molecular dynamics in a plane-wave pseudopotential formulation of density-functional theory. The structural properties of the resulting amorphous models are analyzed, with special attention to coordination statistics. The vibrational and dielectric properties of one of these models are then investiga...

We present an infrared spectroscopy and X-ray diffraction study of hafnium oxide gate dielectric films deposited from hafnium tetra–tertbutoxide, Hf(OC(CH3)3)4. We characterize the crystal phase as a function of thickness and detect the chemical state of impurities in this high-permittivity (high) material. The HfO2 films are composed of monoclinic crystallites in an amorphous matrix. The cryst...