Point defects in thin HfAlOx films probed by monoenergetic positron beams

2003 ◽  
Vol 786 ◽  
Author(s):  
Akira Uedono ◽  
Riichiro Mitsuhashi ◽  
Atsushi Horiuchi ◽  
Kazuyoshi Torii ◽  
Kikuo Yamabe ◽  
...  
Keyword(s):  
Point Defects ◽  
Atomic Layer ◽  
Amorphous Structure ◽  
Open Spaces ◽  
Si Substrates ◽  
Layer Deposition ◽  
The Matrix ◽  
Positron Beams ◽  
Si Films ◽  
Line Shape Parameter

ABSTRACTThin HfAlOx films grown on SiON(0.9 nm)/Si by atomic layer deposition technique were characterized by using monoenergetic positron beams. The lifetimes of positrons in the HfAlOx film after post-deposition annealing (PDA) ranged between 412–403 ps. Since these lifetimes were longer than the lifetime of positrons trapped by point defects in metal oxides, such as LaCoO3, PbTiO3, and BaTiO3, the positrons in HfAlOx films were considered to annihilate from the trapped state by open spaces which exist intrinsically in their amorphous structure. The line-shape parameter S of the Doppler broadening spectrum corresponding to the annihilation of positrons in HfAlOx films decreased by PDA, and the S value decreased with increasing an O2-content in an atmosphere during PDA (0.004–1%). The observed behavior of the S value was attributed to the shrinkage of the open spaces due to the change in the matrix structure of HfAlOx. After P+- and B+-implantation into poly-Si films grown on the HfAlOx films, the diffusion of positrons in the Si substrates toward the HfAlOx film was suppressed. This fact was attributed to positive charges introduced near the HfAlOx films.

scholarly journals Properties and Mechanism of PEALD-In2O3 Thin Films Prepared by Different Precursor Reaction Energy

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 978
Author(s):  
Ming-Jie Zhao ◽  
Zhi-Xuan Zhang ◽  
Chia-Hsun Hsu ◽  
Xiao-Ying Zhang ◽  
Wan-Yu Wu ◽  
...  
Keyword(s):  
Growth Rate ◽  
Substrate Temperature ◽  
Film Growth ◽  
Atomic Layer ◽  
Amorphous Structure ◽  
Reaction Energy ◽  
Film Growth Rate ◽  
In2o3 Film ◽  
Intermediate Temperature Range ◽  
Layer Deposition

Indium oxide (In2O3) film has excellent optical and electrical properties, which makes it useful for a multitude of applications. The preparation of In2O3 film via atomic layer deposition (ALD) method remains an issue as most of the available In-precursors are inactive and thermally unstable. In this work, In2O3 film was prepared by ALD using a remote O2 plasma as oxidant, which provides highly reactive oxygen radicals, and hence significantly enhancing the film growth. The substrate temperature that determines the adsorption state on the substrate and reaction energy of the precursor was investigated. At low substrate temperature (100–150 °C), the ratio of chemically adsorbed precursors is low, leading to a low growth rate and amorphous structure of the films. An amorphous-to-crystalline transition was observed at 150–200 °C. An ALD window with self-limiting reaction and a reasonable film growth rate was observed in the intermediate temperature range of 225–275 °C. At high substrate temperature (300–350 °C), the film growth rate further increases due to the decomposition of the precursors. The resulting film exhibits a rough surface which consists of coarse grains and obvious grain boundaries. The growth mode and properties of the In2O3 films prepared by plasma-enhanced ALD can be efficiently tuned by varying the substrate temperature.

Electrical Properties of Srta2O6 Thin Films Deposited by Plasma Enhanced Atomic Layer Deposition (Peald)

2001 ◽  
Vol 685 ◽  
Author(s):  
Won-Jae Lee ◽  
Chang-Ho Shin ◽  
In-Kyu You ◽  
Il-Suk Yang ◽  
Sang-Ouk Ryu ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Atomic Layer Deposition ◽  
Leakage Current ◽  
Annealing Temperature ◽  
Atomic Layer ◽  
Si Substrates ◽  
Annealing Temperatures ◽  
Layer Deposition ◽  
Current Characteristics

AbstractThe SrTa2O6 (STO) thin films were prepared by plasma enhanced atomic layer deposition (PEALD) with alternating supply of reactant sources, Sr[Ta(C2H5O)5(C4H10NO)]2 {Strontium bis-[tantalum penta-ethoxide dimethyllaminoethoxide]; Sr(Ta(OEt)5▪dmae)2} and O2plasma. It was observed that the uniform and conformal STO thin films were successfully deposited using PEALD and the film thickness per cycle was saturated at about 0.8 nm at 300°C. Electrical properties of SrTa2O6 (STO) thin films prepared on Pt/SiO2/Si substrates with annealing temperatures have been investigated. While the grain size and dielectric constant of STO films increased with increasing annealing temperature, the leakage current characteristics of STO films slightly deteriorated. The leakage current density of a 40nm-STO film was about 5×10−8A/cm2 at 3V.

scholarly journals Growth without Postannealing of Monoclinic VO2 Thin Film by Atomic Layer Deposition Using VCl4 as Precursor

Coatings ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 431 ◽  
Author(s):  
Wen-Jen Lee ◽  
Yong-Han Chang
Keyword(s):  
Vanadium Dioxide ◽  
Atomic Layer ◽  
Amorphous Structure ◽  
Temperature Dependent ◽  
Vanadium Compounds ◽  
Multifunctional Material ◽  
Layer Deposition ◽  
Vanadium Tetrachloride ◽  
First Time ◽  
Deposited Films

Vanadium dioxide (VO2) is a multifunctional material with semiconductor-to-metal transition (SMT) property. Organic vanadium compounds are usually employed as ALD precursors to grow VO2 films. However, the as-deposited films are reported to have amorphous structure with no significant SMT property, therefore a postannealing process is necessary for converting the amorphous VO2 to crystalline VO2. In this study, an inorganic vanadium tetrachloride (VCl4) is used as an ALD precursor for the first time to grow VO2 films. The VO2 film is directly crystallized and grown on the substrate without any postannealing process. The VO2 film displays significant SMT behavior, which is verified by temperature-dependent Raman spectrometer and four-point-probing system. The results demonstrate that the VCl4 is suitably employed as a new ALD precursor to grow crystallized VO2 films. It can be reasonably imagined that the VCl4 can also be used to grow various directly crystallized vanadium oxides by controlling the ALD-process parameters.

scholarly journals Long-range ordered vertical III-nitride nano-cylinder arrays via plasma-assisted atomic layer deposition

2018 ◽  
Vol 6 (24) ◽  
pp. 6471-6482 ◽  
Author(s):  
Ali Haider ◽  
Petro Deminskyi ◽  
Mehmet Yilmaz ◽  
Kholoud Elmabruk ◽  
Ibrahim Yilmaz ◽  
...  
Keyword(s):  
Low Temperature ◽  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Low Temperature Plasma ◽  
Anodized Aluminum ◽  
Temperature Plasma ◽  
Anodized Aluminum Oxide ◽  
Si Substrates ◽  
Cylinder Arrays ◽  
Layer Deposition

In this work, we demonstrate vertical GaN, AlN, and InN hollow nano-cylindrical arrays (HNCs) grown on Si substrates using anodized aluminum oxide (AAO) membrane templated low-temperature plasma-assisted atomic layer deposition (PA-ALD).

scholarly journals Low Resistance TiO2/p-Si Heterojunction for Tandem Solar Cells

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2857
Author(s):  
Steponas Ašmontas ◽  
Maksimas Anbinderis ◽  
Jonas Gradauskas ◽  
Remigijus Juškėnas ◽  
Konstantinas Leinartas ◽  
...  
Keyword(s):  
Atomic Layer ◽  
Tandem Solar Cells ◽  
Si Substrates ◽  
Layer Deposition ◽  
Current Voltage ◽  
Niobium Doped ◽  
Specific Contact ◽  
Carrier Tunneling ◽  
P Type ◽  
Deposited Films

Niobium-doped titanium dioxide (Ti1−xNbxO2) films were grown on p-type Si substrates at low temperature (170 °C) using an atomic layer deposition technique. The as-deposited films were amorphous and showed low electrical conductivity. The films became electrically well-conducting and crystallized into the an anatase structure upon reductive post-deposition annealing at 600 °C in an H2 atmosphere for 30 min. It was shown that the Ti0.72Nb0.28O2/p+-Si heterojunction fabricated on low resistivity silicon (10−3 Ω cm) had linear current–voltage characteristic with a specific contact resistivity as low as 23 mΩ·cm2. As the resistance dependence on temperature revealed, the current across the Ti0.72Nb0.28O2/p+-Si heterojunction was mainly determined by the band-to-band charge carrier tunneling through the junction.

Selective Atomic Layer Deposition of Metal Oxide Thin Films on Patterned Self-Assembled Monolayers Formed by Microcontact Printing

2007 ◽  
Vol 7 (11) ◽  
pp. 3758-3764
Author(s):  
Byoung H. Lee ◽  
Myung M. Sung
Keyword(s):  
Thin Films ◽  
Atomic Layer Deposition ◽  
Metal Oxide ◽  
Microcontact Printing ◽  
Atomic Layer ◽  
Oxide Thin Films ◽  
Metal Oxide Thin Films ◽  
Si Substrates ◽  
Layer Deposition ◽  
Assembled Monolayers

We demonstrate a selective atomic layer deposition of TiO2, ZrO2, and ZnO thin films on patterned alkylsiloxane self-assembled monolayers. Microcontact printing was done to prepare patterned monolayers of the alkylsiloxane on Si substrates. The patterned monolayers define and direct the selective deposition of the metal oxide thin films using atomic layer deposition. The selective atomic layer deposition is based on the fact that the metal oxide thin films are selectively deposited only on the regions exposing the silanol groups of the Si substrates because the regions covered with the alkylsiloxane monolayers do not have any functional group to react with precursors.

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