Recently, as the process of the MOS device becomes more detailed, and the degree of integration thereof increases, many problems such as leakage current due to an increase in electron tunneling due to the thickness of SiO2 used as a gate oxide have occurred. In order to overcome the limitation of SiO2, many studies have been conducted on HfO2 that has a thermodynamic stability with silicon during processing, has a higher dielectric constant than SiO2, and has an appropriate band gap. In this study, HfO2, which is attracting attention in various fields, was doped with Al and the change in properties according to its concentration was studied. Al-doped HfO2 thin film was deposited using Plasma Enhanced Atomic Layer Deposition (PEALD), and the structural and electrical characteristics of the fabricated MIM device were evaluated. The results of this study are expected to make an essential cornerstone in the future field of next-generation semiconductor device materials.
Titanium oxide (TiO2) thin films were synthesized on polymer insulator and Si substrates by atomic layer deposition (ALD) method. The surface and electrical properties of TiO2 films synthesized at various ALD cycle numbers were investigated. The synthesized TiO2 films exhibited higher contact angle and smooth surface. The contact angle of TiO2 films was increased with the increase of ALD-cycle number. Also, the rms surface roughness of films was slightly rough with the increase of ALD-cycle number. The leakage current on TiO2 film surface synthesized at various conditions were uniformed, and the values were decreased with the increase of ALD-cycle number. In the results, the performance of TiO2 films for self-cleaning critically depended on a number of ALD-cycle.
We have investigated the properties of Al-doped ZnO (AZO) thin films as functions of atomic layer deposition (ALD) oxidants. AZO transparent conducting oxides (TCOs) layer was deposited by ALD with adding trimethylaluminum (TMA) and diethylzinc (DEZn). AZO films were deposited at low temperature with H2O and O3 as oxidants. Electrical, optical and structural properties of AZO thin films were investigated by 4-point probe, Hall effect measurement, UV-VIS, and AFM. Microstructure and atomic bonding states were investigated by HRXRD and XPS. The resistivity of AZO films grown using H2O was lower than the films grown using H2O and O3, by approximately two orders of magnitude. The differences in oxygen vacancy peak intensity of AZO films were correlated to the optical and electrical properties.
Renewable energy sources such as solar, wind and hydro provides utilizing renewable power and reduce the using fossil fuels. On the other hand, it is too critical to apply power system due to the intermittent nature of renewable energy sources, the continuous fluctuations of the power load, and the storage with high energy density. Energy storage system, including pumped-hydroelectric energy storage, compressed-air energy storage, superconducting magnetic energy storage, and electrochemical devices like batteries, super capacitors and others have shown that solve some of the challenges. In this paper, were view the current state of applications of energy storage systems, and atomic layer deposition technology, graphene materials on the energy storage systems and processes.
We investigated the effects of low temperature (500℃) O2 annealing on the characteristics of hafnium silicate (HfSi(x)O(y)) films deposited on a Si substrate by atomic layer deposition (ALD). We found that the post deposition annealing under oxidizing ambient causes the oxidation of residual Hf metal components, resulting in the improvement of electrical characteristics such as flat band voltage shift (ΔV(fb)) by hysteresis without oxide capacitance reduction. We suggest that post deposition annealing under oxidizing ambient is necessary to improve the electrical characteristics of HfSi(x)O(y) films deposited by ALD.
Abstract: Carbon aerogels are promising materials as electrodes for electrical double layer capacitors (EDLCs). An optimum process is presented for synthesis of nanoporous carbon aerogels via pyrolyzing resorcinol-formaldehyde (RF) organic aerogels, which could be cost-effectively manufactured from RF wet gels. The major reactions between resorcinol and formaldehyde include an addition reaction to form hydroxymethyl derivatives (-CH(2)OH), and then a condensation reaction of the hydroxymethyl derivatives (-CH(2)-)- and methylene ether (-CH(2)OCH(2)-) bridged compounds. The textural properties of carbon aerogels obtained were characterized by nitrogen adsorption/desorption analysis and SEM and TEM. The application of the resultant carbon for electrodes of electric double layers capacitor (EDLC) in organic TEABF4/ACN electrolyte indicated that the ESR, as low as 55 mΩ, was smaller than for commercially activated carbons. And EDLC with carbon Aerogel electrodes has an excellent stable more than for commercially activated carbons.