scholarly journals Direct Epitaxial Nanometer-Thin InN of High Structural Quality on 4H-SiC by Atomic Layer Deposition

2020 ◽  
Author(s):  
Chih-Wei Hsu ◽  
Petro Deminskyi ◽  
Ivan Martinovic ◽  
Ivan G. Ivanov ◽  
Justinas Palisaitis ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Indium Nitride ◽  
Atomic Layer ◽  
Structural Quality ◽  
High Electron ◽  
X Ray Diffraction ◽  
High Quality ◽  
Subsequent Formation ◽  
Transmission Electron ◽  
Layer Deposition

<div>Indium nitride (InN) is a highly promising material for high frequency electronics given its</div><div>low band gap and high electron mobility. The development of InN-based devices is hampered</div><div>by the limitations in depositing very thin InN films of high quality. We demonstrate growth of</div><div>high-structural-quality nanometer thin InN films on 4H-SiC by atomic layer deposition (ALD).</div><div>High resolution X-ray diffraction and transmission electron microscopy show epitaxial growth</div><div>and an atomically sharp interface between InN and 4H-SiC. The InN film is fully relaxed already after a few atomic layers and shows a very smooth morphology where the low surface</div><div>roughness (0.14 nm) is found to reproduced sub-nanometer surface features of the substrate. Raman measurements show an asymmetric broadening caused by grains in the InN film. Our results show the potential of ALD to prepare high quality nanometer-thin InN films for subsequent formation of heterojunctions.</div>

scholarly journals Direct Epitaxial Nanometer-Thin InN of High Structural Quality on 4H-SiC by Atomic Layer Deposition

2020 ◽  
Author(s):  
Chih-Wei Hsu ◽  
Petro Deminskyi ◽  
Ivan Martinovic ◽  
Ivan G. Ivanov ◽  
Justinas Palisaitis ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Indium Nitride ◽  
Atomic Layer ◽  
Structural Quality ◽  
High Electron ◽  
X Ray Diffraction ◽  
High Quality ◽  
Subsequent Formation ◽  
Transmission Electron ◽  
Layer Deposition

<div>Indium nitride (InN) is a highly promising material for high frequency electronics given its</div><div>low band gap and high electron mobility. The development of InN-based devices is hampered</div><div>by the limitations in depositing very thin InN films of high quality. We demonstrate growth of</div><div>high-structural-quality nanometer thin InN films on 4H-SiC by atomic layer deposition (ALD).</div><div>High resolution X-ray diffraction and transmission electron microscopy show epitaxial growth</div><div>and an atomically sharp interface between InN and 4H-SiC. The InN film is fully relaxed already after a few atomic layers and shows a very smooth morphology where the low surface</div><div>roughness (0.14 nm) is found to reproduced sub-nanometer surface features of the substrate. Raman measurements show an asymmetric broadening caused by grains in the InN film. Our results show the potential of ALD to prepare high quality nanometer-thin InN films for subsequent formation of heterojunctions.</div>

scholarly journals Direct Epitaxial Nanometer-Thin InN of High Structural Quality on 4H-SiC by Atomic Layer Deposition

2020 ◽  
Author(s):  
Chih-Wei Hsu ◽  
Petro Deminskyi ◽  
Ivan Martinovic ◽  
Ivan G. Ivanov ◽  
Justinas Palisaitis ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Indium Nitride ◽  
Atomic Layer ◽  
Structural Quality ◽  
High Electron ◽  
X Ray Diffraction ◽  
High Quality ◽  
Subsequent Formation ◽  
Transmission Electron ◽  
Layer Deposition

<div>Indium nitride (InN) is a highly promising material for high frequency electronics given its</div><div>low band gap and high electron mobility. The development of InN-based devices is hampered</div><div>by the limitations in depositing very thin InN films of high quality. We demonstrate growth of</div><div>high-structural-quality nanometer thin InN films on 4H-SiC by atomic layer deposition (ALD).</div><div>High resolution X-ray diffraction and transmission electron microscopy show epitaxial growth</div><div>and an atomically sharp interface between InN and 4H-SiC. The InN film is fully relaxed already after a few atomic layers and shows a very smooth morphology where the low surface</div><div>roughness (0.14 nm) is found to reproduced sub-nanometer surface features of the substrate. Raman measurements show an asymmetric broadening caused by grains in the InN film. Our results show the potential of ALD to prepare high quality nanometer-thin InN films for subsequent formation of heterojunctions.</div>

scholarly journals Hexacoordinated Gallium(III) Triazenide Precursor for Epitaxial Gallium Nitride by Atomic Layer Deposition

2020 ◽  
Author(s):  
Polla Rouf ◽  
Rouzbeh Samii ◽  
Karl Rönnby ◽  
Babak Bakhit ◽  
Sydney Buttera ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
Atomic Layer Deposition ◽  
Electronic Devices ◽  
Atomic Layer ◽  
High Electron Mobility Transistor ◽  
Deposition Process ◽  
Single Step ◽  
High Electron ◽  
High Quality ◽  
Layer Deposition

Gallium nitride (GaN) is the main component of modern-day high electron mobility transistor electronic devices due to its favorable electronic properties. As electronic devices become smaller with more complex architecture, the ability to deposit high-quality GaN films at low temperature is required. Herein, we report a new highly volatile Ga(III) triazenide precursor and demonstrate its ability to deposit high-quality epitaxial GaN by atomic layer deposition (ALD). This new Ga(III) triazenide precursor, the first hexacoordinated M–N bonded Ga(III) precursor used in a vapor deposition process, was easily synthesized and purified by sublimation. Thermogravimetric analysis showed single step volatilization with an onset temperature of 150 °C and negligible residual mass. Three temperature intervals with self-limiting growth were observed when depositing GaN films. In the second growth interval, the films were found to be near stoichiometric with very low levels of impurities and epitaxial orientation on 4H-SiC without an AlN seed layer. The films grown at 350 °C were found to be smooth with a sharp interface between the substrate and film. The bandgap of these films was 3.41 eV with the Fermi level at 1.90 eV, showing that the GaN films were unintentionally <i>n</i>-type doped. This new triazenide precursor enables ALD of GaN for semiconductor applications and provides a new Ga(III) precursor for future deposition processes.

AlGaN/GaN multiple quantum wells grown by using atomic layer deposition technique

2008 ◽  
Vol 1068 ◽  
Author(s):  
Ming-Hua Lo ◽  
Zhen-Yu Li ◽  
Shih-Wei Chen ◽  
Jhih-Cang Hong ◽  
Ting-Chang Lu ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Quantum Wells ◽  
Atomic Layer ◽  
Atomic Force Microscope Image ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
X Ray Diffraction ◽  
Atomic Force ◽  
Transmission Electron ◽  
Layer Deposition

ABSTRACTIn this work, we report on the growth of ultraviolet (UV) AlGaN/GaN multiple quantum wells (MQWs) structure using atomic layer deposition (ALD) technique. The AlGaN/GaN MQW sample grown on the sapphire substrate consisted of three GaN QWs and four AlGaN barriers comprised AlN/GaN superlattices (SLs). The root-mean-square value of the surface morphology was only 0.35 nm observed from the atomic force microscope image and no crack was found on the surface. Both of the high resolution X-ray diffraction curves and transmission electron microscope images showed sharp interfaces between SLs layers and QWs with good periodicity. These results demonstrate that the ALD could be a very useful technique for controlling the crystalline quality and thickness of the III-nitride epilayer.

Ti Coating of Nanocrystalline Diamond by Atomic Layer Deposition

2006 ◽  
Vol 304-305 ◽  
pp. 48-51 ◽  
Author(s):  
Jian Bing Zang ◽  
Jing Lu ◽  
Yan Hui Wang ◽  
X.H. Qi ◽  
Yun Gang Yuan
Keyword(s):  
Atomic Layer Deposition ◽  
Polycrystalline Diamond ◽  
High Strength ◽  
Atomic Layer ◽  
Nanocrystalline Diamond ◽  
X Ray Diffraction ◽  
Diamond Surfaces ◽  
Transmission Electron ◽  
Layer Deposition ◽  
Binary Reaction

Nanocrystalline diamond compact possesses not only the advantageous performance of polycrystalline diamond but also the high strength and the high toughness of nano-ceramics. However, single-phase nanocrystalline diamond compact is very difficult to sinter because of a huge amount of oxygen-containing and nitrogen-containing functional groups absorbed on the surface of nanocrystalline diamond. In this paper, atomic layer deposition (ALD) method has been used to coat nanocrystalline diamond with titanium, which will promote the bonding of nanocrystalline diamond as the bond in polycrystalline diamond. In vacuum, the H2 and TiCl4 reactants were employed alternately in an ABAB… binary reaction sequence to achieve Ti layer, which reacted with diamond matrix and formed TiC in the coating, realizing strong chemical bonding between the coating and the diamond. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were utilized to study the structure and the morphology of the coating. The results confirmed the formation of titanium carbide at the depositing temperature 500°C. The darker spots and strips observed on nanocrystalline diamond particles by TEM were proved to be TiC and the nucleation and subsequent growth of TiC preferentially occurred in the defects as twin zones and dislocation areas on diamond surfaces.

scholarly journals “Intelligent” Pt Catalysts Based on Thin LaCoO3 Films Prepared by Atomic Layer Deposition

Inorganics ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 113 ◽  
Author(s):  
Xinyu Mao ◽  
Alexandre C. Foucher ◽  
Eric A. Stach ◽  
Raymond J. Gorte
Keyword(s):  
Atomic Layer Deposition ◽  
Co Adsorption ◽  
Atomic Layer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Highly Active ◽  
Transmission Electron ◽  
Layer Deposition ◽  
Scanning Transmission ◽  
Water Gas

LaCoO3 films were deposited onto MgAl2O4 powders by atomic layer deposition (ALD) and then used as catalyst supports for Pt. X-ray diffraction (XRD) showed that the 0.5 nm films exhibited a perovskite structure after redox cycling at 1073 K, and scanning transmission electron microscopy and elemental mapping via energy-dispersive X-ray spectroscopy (STEM/EDS) data demonstrated that the films covered the substrate uniformly. Catalysts prepared with 3 wt % Pt showed that the Pt remained well dispersed on the perovskite film, even after repeated oxidations and reductions at 1073 K. Despite the high Pt dispersion, CO adsorption at room temperature was negligible. Compared with conventional Pt on MgAl2O4, the reduced forms of the LaCoO3-containing catalyst were highly active for the CO oxidation and water gas shift (WGS) reactions, while the oxidized catalysts showed much lower activities. Surprisingly, the reduced catalysts were much less active than the oxidized catalysts for toluene hydrogen. Catalysts prepared from thin films of Co3O4 or La2O3 exhibited properties more similar to Pt/MgAl2O4. Possible reasons for how LaCoO3 affects properties are discussed.

scholarly journals Decoration of Vertically Aligned Carbon Nanotubes with Semiconductor Nanoparticles Using Atomic Layer Deposition

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1095 ◽  
Author(s):  
Anna Szabó ◽  
László Péter Bakos ◽  
Dániel Karajz ◽  
Tamás Gyulavári ◽  
Zsejke-Réka Tóth ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
X Ray Diffraction ◽  
Vertically Aligned Carbon Nanotubes ◽  
X Ray ◽  
Transmission Electron ◽  
Layer Deposition ◽  
Aligned Carbon Nanotubes ◽  
Vertically Aligned

Vertically aligned carbon nanotubes (VACNTs or “CNT forest”) were decorated with semiconductor particles (TiO2 and ZnO) by atomic layer deposition (ALD). Both the structure and morphology of the components were systematically studied using scanning (SEM) and high resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDX), Raman spectroscopy, and X-ray diffraction (XRD) methods. Characterization results revealed that the decoration was successful in the whole bulk of VACNTs. The effect of a follow-up heat treatment was also investigated and its effect on the structure was proved. It was attested that atomic layer deposition is a suitable technique for the fabrication of semiconductor/vertically aligned carbon nanotubes composites. Regarding their technological importance, we hope that semiconductor/CNT forest nanocomposites find potential application in the near future.

scholarly journals Two-Dimensional Perovskite Crystals Formed by Atomic Layer Deposition of CaTiO3 on γ-Al2O3

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2207
Author(s):  
Tianyu Cao ◽  
Ohhun Kwon ◽  
Chao Lin ◽  
John M. Vohs ◽  
Raymond J. Gorte
Keyword(s):  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Average Thickness ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Entire Surface ◽  
X Ray ◽  
Transmission Electron ◽  
Layer Deposition ◽  
20 Nm

CaTiO3 films with an average thickness of 0.5 nm were deposited onto γ-Al2O3 by Atomic Layer Deposition (ALD) and then characterized by a range of techniques, including X-ray Diffraction (XRD) and High-Resolution, Transmission Electron Microscopy (HRTEM). The results demonstrate that the films form two-dimensional crystallites over the entire surface. Lattice fringes from HRTEM indicate that the crystallites range in size from 5 to 20 nm and are oriented in various directions. Films of the same thickness on SiO2 remained amorphous, indicating that the support played a role in forming the crystallites.

Spectroscopic study of La2O3 thin films deposited by indigenously developed plasma-enhanced atomic layer deposition system

2018 ◽  
Vol 32 (19) ◽  
pp. 1840074 ◽  
Author(s):  
Viral Barhate ◽  
Khushabu Agrawal ◽  
Vilas Patil ◽  
Sumit Patil ◽  
Ashok Mahajan
Keyword(s):  
Thin Films ◽  
Atomic Layer Deposition ◽  
Spectroscopic Study ◽  
Photoelectron Spectroscopy ◽  
Atomic Layer ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Transmission Electron ◽  
Layer Deposition

The spectroscopic study of La2O3 thin films deposited over Si and SiC at low RF power of 25 W by using indigenously developed plasma-enhanced atomic layer deposition (IDPEALD) system has been investigated. The tris (cyclopentadienyl) lanthanum (III) and O2 plasma were used as a source precursor of lanthanum and oxygen, respectively. The [Formula: see text]1.2 nm thick La2O3 over SiC and Si has been formed based on our recipe confirmed by means of cross-sectional transmission electron microscopy. The structural characterization of deposited films was performed by means of X-ray photoelectron Spectroscopy (XPS) and X-ray Diffraction (XRD). The XPS result confirms the formation of 3[Formula: see text] oxidation state of the lanthania. The XRD results reveals that, deposited La2O3 films deposited on SiC are amorphous in nature compare to that of films on Si. The AFM micrograph shows the lowest roughness of 0.26 nm for 30 cycles of La2O3 thin films.

scholarly journals Hexacoordinated Gallium(III) Triazenide Precursor for Epitaxial Gallium Nitride by Atomic Layer Deposition

2020 ◽  
Author(s):  
Polla Rouf ◽  
Rouzbeh Samii ◽  
Karl Rönnby ◽  
Babak Bakhit ◽  
Sydney Buttera ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
Atomic Layer Deposition ◽  
Electronic Devices ◽  
Atomic Layer ◽  
High Electron Mobility Transistor ◽  
Deposition Process ◽  
Single Step ◽  
High Electron ◽  
High Quality ◽  
Layer Deposition

Gallium nitride (GaN) is the main component of modern-day high electron mobility transistor electronic devices due to its favorable electronic properties. As electronic devices become smaller with more complex architecture, the ability to deposit high-quality GaN films at low temperature is required. Herein, we report a new highly volatile Ga(III) triazenide precursor and demonstrate its ability to deposit high-quality epitaxial GaN by atomic layer deposition (ALD). This new Ga(III) triazenide precursor, the first hexacoordinated M–N bonded Ga(III) precursor used in a vapor deposition process, was easily synthesized and purified by sublimation. Thermogravimetric analysis showed single step volatilization with an onset temperature of 150 °C and negligible residual mass. Three temperature intervals with self-limiting growth were observed when depositing GaN films. In the second growth interval, the films were found to be near stoichiometric with very low levels of impurities and epitaxial orientation on 4H-SiC without an AlN seed layer. The films grown at 350 °C were found to be smooth with a sharp interface between the substrate and film. The bandgap of these films was 3.41 eV with the Fermi level at 1.90 eV, showing that the GaN films were unintentionally <i>n</i>-type doped. This new triazenide precursor enables ALD of GaN for semiconductor applications and provides a new Ga(III) precursor for future deposition processes.

Sign in / Sign up

Export Citation Format

Share Document