SELECTIVE DRY ETCHING OF GaN OVER AlGaN IN BCL3/SF6 MIXTURES

2004 ◽  
Vol 14 (03) ◽  
pp. 756-761 ◽  
Author(s):  
D. BUTTARI ◽  
A. CHINI ◽  
A. CHAKRABORTY ◽  
L. MCCARTHY ◽  
H. XING ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Morphology ◽  
Inductively Coupled Plasma ◽  
Laser Interferometry ◽  
Force Microscopy ◽  
Inductively Coupled ◽  
Icp Etching ◽  
Atomic Force ◽  
Template Process ◽  
Wide Range

Inductively coupled plasma (ICP) etching of GaN with high selectivity over Al .22 Ga .78 N in BCl 3/ SF 6 mixtures has been studied. Selectivity and surface morphology were investigated over a wide range of pressures (3.75–37.5mTorr), RF powers (30–120 W), ICP powers (100–400 W), and SF 6/ BCl 3 ratios (0.1–0.7). Higher pressures, lower dc biases, and higher SF 6/ BCl 3 ratios increased the GaN to AlGaN selectivity. Selectivities up to 25 were measured by laser interferometry. A root mean square (rms) surface roughness of 0.67 nm was measured by atomic force microscopy (AFM) after removal of 0.5 μm from a GaN template (process selectivity: 15, as-grown rms surface roughness: 0.56 nm). A degradation in surface morphology, with the gradual formation of pits, was observed for selectivities above 10.

Growth of Germanium on Porous Silicon (001)

1996 ◽  
Vol 452 ◽  
Author(s):  
W. H. Thompson ◽  
Z. Yamani ◽  
H. M. Nayfeh ◽  
M.-A. Hasan ◽  
J. E. Greene ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Porous Silicon ◽  
Molecular Beam Epitaxy ◽  
Surface Morphology ◽  
Molecular Beam ◽  
Porous Si ◽  
Force Microscopy ◽  
Atomic Force ◽  
Nm Range

AbstractThe surface morphology of Ge grown on Si (001) and porous Si(001) by molecular beam epitaxy at 380 °C is examined using atomic force microscopy (AFM). For layer thicknesses of 30 nm, the surface shows islanding while still maintaining some of the underlying roughness of the surface of porous Si. For thicknesses in the 100 nm range, the surface roughness is not visible, but the islanding persists. Unlike the case of silicon where islands tend to merge and nearly disappear as the thickness of the deposited layer rises, we observe on the porous layer the persistence of the islands with no merging even for macroscopic thicknesses as large as 0.73 microns.

Mitigation of BPD by Pre-Epigrowth High Temperature Substrate Annealing

2016 ◽  
Vol 858 ◽  
pp. 233-236 ◽  
Author(s):  
Nadeemullah A. Mahadik ◽  
Robert E. Stahlbush ◽  
Eugene A. Imhoff ◽  
M.J. Tadjer ◽  
G.E. Ruland ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
High Temperature ◽  
Surface Morphology ◽  
Substrate Surface ◽  
High Temperature Annealing ◽  
Force Microscopy ◽  
Atomic Force ◽  
Substrate Annealing ◽  
Edge Dislocations

Basal Plane Dislocations (BPD) intersecting the SiC substrate surface were converted to threading edge dislocations (TED) by high temperature annealing of the substrates in the temperature range of 1750 °C – 1950 °C. Successively, epitaxial growth on annealed as well as non-annealed samples was performed, concurrently, to investigate the effect of the substrate annealing on BPD mitigation in the epilayers. For the 1950 °C/10min anneal, a 3x reduction in BPD density was observed. Additionally, surface roughness measured using atomic force microscopy revealed no degradation in surface morphology of the grown epilayers after annealing.

scholarly journals Influence of diatomite microstructure on its adsorption capacity for Pb(II)

2009 ◽  
Vol 41 (3) ◽  
pp. 309-317 ◽  
Author(s):  
S. Nenadovic ◽  
M. Nenadovic ◽  
R. Kovacevic ◽  
Lj. Matovic ◽  
B. Matovic ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Atomic Emission ◽  
Emission Spectrometry ◽  
Wastewater Remediation ◽  
X Ray Diffraction ◽  
Plasma Atomic Emission Spectrometry ◽  
Force Microscopy ◽  
Inductively Coupled ◽  
Atomic Force ◽  
Treated Sample

The effect of microstructural changes caused by mechanical modification on adsorption properties of diatomite samples were investigated. The microstructure has been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) while the degree of metal adsorption was evaluated by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP AES). The results show that metal sorption capacity of diatomite is considerably improved after mechanical modification and it can be attributed to amorphysation of the material. Immobilization efficiency increased from 22% for untreated to 81% for the treated sample after 5h at BPR 4.This qualifies natural diatomite as a material for wastewater remediation.

Surface Morphology, Crystal Orientation and Scratch Properties of Au/NiCr/Ta Multi-Layered Metallic Films

2007 ◽  
Vol 353-358 ◽  
pp. 1863-1866
Author(s):  
Wu Tang ◽  
Long Jiang Deng ◽  
Ke Wei Xu ◽  
Jian Lu
Keyword(s):  
Surface Roughness ◽  
Surface Morphology ◽  
Substrate Temperature ◽  
Crystal Orientation ◽  
Scratch Test ◽  
Test Method ◽  
Metallic Films ◽  
Force Microscopy ◽  
Atomic Force ◽  
Friction Mode

The crystal orientation, surface morphology, surface roughness and scratch properties of Au/NiCr/Ta multi-layered metallic films was examined by X-ray diffraction (XRD), atomic force microscopy (AFM) and a scratch test method, respectively. It was clarified that the surface morphology and surface roughness depend on the substrate temperature. The surface roughness decreases from 4.259nm to 2.935nm when substrate temperature changed from 100°C to 180°C, and then increases when substrate temperature above 180°C. The XRD revealed that there are only Au diffraction peaks with highly textured having a Au-(111) or a mixture of Au-(111) and Au-(200) orientation. The micro-scratch test reveals that both modes can be used for conventionally critical load determination, but the friction mode can additionally reflect the changes at different metallic film layers, the critical characteristic load was not sensitive to substrate temperature.

scholarly journals Partitioning and Surficial Segregation of Trace Elements in Iron Oxides in Hydrothermal Fluid Systems

Minerals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 57
Author(s):  
Nikolay Smagunov ◽  
Vladimir Tauson ◽  
Sergey Lipko ◽  
Dmitriy Babkin ◽  
Taisa Pastushkova ◽  
...  
Keyword(s):  
Trace Elements ◽  
Inductively Coupled Plasma ◽  
Absorption Spectrometry ◽  
X Ray ◽  
Force Microscopy ◽  
Inductively Coupled ◽  
Atomic Force ◽  
Fluid Systems ◽  
Nonautonomous Phase ◽  
Plasma Mass Spectrometry

Partitioning experiments were done by hydrothermal synthesis of crystals containing trace elements (TEs) by internal sampling of fluid at the temperature of 450 °C and pressure of 1 kbar. The crystal phases obtained were magnetite, hematite, and Ni-spinel, which were studied using X-ray diffraction (XRD), X-ray electron probe microanalysis (EPMA), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), atomic absorption spectrometry (AAS), and atomic force microscopy (AFM). The solutions from the sampler’s fluid probes were analysed by AAS for TEs included elements of the iron group plus aluminium. The highest co-crystallisation coefficients of TE and Fe between mineral and fluid (DTE/Fe) in magnetite were measured for V, Al, Ni and Cr (in decreasing order of n units in value), a lower value was observed for Co (2 × 10−1), and still lower values for Ti, Zn, and Mn (n × 10−2–10−3). In hematite, DTE/Fe values were highest for Al and V (order of n units in value), while lower values characterised Ti, Cr, and Co (n × 10−1–10−3), and the lowest values were exhibited by Cu, Mn, and Zn (n × 10−5). Copper was confirmed to be the most incompatible with all minerals studied; however, Cu had a high content on crystal surfaces. This surficial segregation contributes to the average TE concentration even when a thin layer of nonautonomous phase (NAP) is enriched in the element of interest. The accumulation of TEs on the surface of crystals increased bulk content 1–2 orders of magnitude above the content of structurally-bound elements even in coarse crystals. The inverse problem—evaluation of TE/Fe ratios in fluids involved in the formation of magnetite-containing deposits—revealed that the most abundant metals in fluids were Fe followed by Mn, Zn, and Cu, which comprised 10 to 30% of the total iron content.

Post-CMP Cleaning of Atom-Scale Planarization Surface of Computer Hard Disk Substrate

2010 ◽  
Vol 97-101 ◽  
pp. 1181-1185
Author(s):  
Nai Jing Bu ◽  
Hong Lei ◽  
Ru Ling Chen ◽  
Xiao Li Hu
Keyword(s):  
Inductively Coupled Plasma ◽  
Hard Disk ◽  
Atomic Emission ◽  
Force Microscopy ◽  
Inductively Coupled ◽  
Atomic Force ◽  
Cleaning Solution ◽  
Hard Disk Substrate ◽  
Cleaning Methods ◽  
Disk Substrate

At present, the surface of computer hard disk substrate has reached atom-scale planarization after chemical mechanical polishing (CMP). Post-CMP cleaning is one of the key factors influencing the CMP performances. During cleaning, cleaning solution and cleaning methods play a key role in cleaning quality and effectiveness. In the present paper, alkylpolyoxyethylene alcohol carboxylic ester (FAC) surfactant was synthesized and its cleaning performances on atom-scale planarization surface of computer hard disk substrate were investigated. Microscope analysis indicated that the prepared detergent containing FAC surfactant exhibited improved cleaning performances compared with the commercial detergent. Further, inductively coupled plasma (ICP) atomic emission spectrometer, auger electron spectrogram (AES) and atomic force microscopy (AFM) analyses after static corrosion test showed that the prepared cleaning solution had lower corrosion to hard disk substrate.

scholarly journals Analysis of Perovskite Oxides Etching Using Argon Inductively Coupled Plasmas for Photonics Applications

2020 ◽  
Author(s):  
Guanyu Chen ◽  
Eric Jun Hao Cheung ◽  
Yu Cao ◽  
Jisheng Pan ◽  
Aaron J. Danner
Keyword(s):  
Photoelectron Spectroscopy ◽  
Perovskite Oxides ◽  
Inductively Coupled Plasmas ◽  
Barium Titanium Oxide ◽  
X Ray ◽  
Force Microscopy ◽  
Inductively Coupled ◽  
Icp Etching ◽  
Atomic Force ◽  
Coupled Plasmas

Abstract We analyzed the dry etching of perovskite oxides using argon-based inductively coupled plasmas (ICP) for photonics applications. Various chamber conditions and their effects on etching rates have been demonstrated based on Z-cut lithium niobate (LN). The measured results are predictable and repeatable and can be applied to other perovskite oxides, such as X-cut LN and barium titanium oxide (BTO). The surface roughness is better for both etched LN and BTO compared with their as-deposited counterparts as confirmed by atomic force microscopy (AFM). Both the energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) methods have been used for surface chemical component comparisons, qualitative and quantitative, and no obvious surface state changes are observed according to the measured results. An optical waveguide fabricated with the optimized argon-based ICP etching was measured to have -3.7 dB/cm loss near 1550 nm wavelength for Z-cut LN, which validates this kind of method for perovskite oxides etching in photonics applications.

Effect of Borax Content on Composition and Microstructure of Boride Layer by Electrodeposition

2011 ◽  
Vol 179-180 ◽  
pp. 508-512 ◽  
Author(s):  
Hai Li Yang ◽  
Ning He ◽  
Guo Zhang Tang ◽  
Yun Gang Li ◽  
Yu Zhu Zhang
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Glow Discharge ◽  
Surface Morphology ◽  
Molten Salts ◽  
Boride Layer ◽  
Silicon Steel ◽  
Force Microscopy ◽  
Atomic Force ◽  
Compositional Depth Profile

Boronizing of silicon steel is performed by electrodeposition in KCl-NaCl-NaF-Na2B4O710H2O molten salts with different amounts of borax. The effect of borax content on composition and microstructure of boride layer is studied. The compositional depth profile of boride layer is measured using the glow discharge spectrometry (GDS) and the depth from the surface to the substrate is taken as the layer thickness. The surface morphology is studied by atomic force microscopy (AFM). It is found that the thickness of the boride layer reached maximum values when the borax content is 0.05mol. The roughness decreases with raising borax content from 0.01 to 0.05mol while the further increase of borax content from 0.05 to 0.1mol results in increase of roughness. The boride layer formed at borax content 0.05 mol shows smallest values of surface roughness.

Structure and Optical Properties of Si Films Deposited by Inductively Coupled Plasma CVD at Room Temperature

2007 ◽  
Vol 336-338 ◽  
pp. 2228-2231
Author(s):  
Xiao Qiang Wang ◽  
De Yan He ◽  
Jun Shuai Li
Keyword(s):  
Optical Properties ◽  
Inductively Coupled Plasma ◽  
Room Temperature ◽  
Chemical Vapor ◽  
Plasma Chemical Vapor Deposition ◽  
Force Microscopy ◽  
Inductively Coupled ◽  
Atomic Force ◽  
Nano Crystalline ◽  
Si Films

Si films were deposited by inductively coupled plasma chemical vapor deposition at room temperature with a mixture of SiH4/H2. The microstructure of the film was characterized with Fourier transform of infrared, Raman spectroscopy, atomic force microscopy. We found that SiH4 concentration strongly affects the structure of Si films and nano-crystalline film can be synthesized at room temperature by optimizing the silane concentration. The analysis for optical properties of the films suggested that the optical band gap EOPT of films are distinctively lower than those of amorphous Si films. It has been observed that the EOPT of sample decreases with the increasing of H content in film.

scholarly journals Analysis of perovskite oxides etching using argon inductively coupled plasmas for photonics applications

2021 ◽  
Author(s):  
Guanyu Chen ◽  
Eric Jun Hao Cheung ◽  
Yu Cao ◽  
Jisheng Pan ◽  
Aaron J. Danner
Keyword(s):  
Photoelectron Spectroscopy ◽  
Perovskite Oxides ◽  
Inductively Coupled Plasmas ◽  
Barium Titanium Oxide ◽  
X Ray ◽  
Force Microscopy ◽  
Inductively Coupled ◽  
Icp Etching ◽  
Atomic Force ◽  
Coupled Plasmas

Abstract We analyzed the dry etching of perovskite oxides using argon-based inductively coupled plasmas (ICP) for photonics applications. Various chamber conditions and their effects on etching rates have been demonstrated based on Z-cut lithium niobate (LN). The measured results are predictable and repeatable and can be applied to other perovskite oxides, such as X-cut LN and barium titanium oxide (BTO). The surface roughness is better for both etched LN and BTO compared with their as-deposited counterparts as confirmed by atomic force microscopy (AFM). Both the energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) methods have been used for surface chemical component comparisons, qualitative and quantitative, and no obvious surface state changes are observed according to the measured results. An optical waveguide fabricated with the optimized argon-based ICP etching was measured to have − 3.7 dB/cm loss near 1550 nm wavelength for Z-cut LN, which validates this kind of method for perovskite oxides etching in photonics applications.

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