Etching of 4° and 8° 4H-SiC Using Various Hydrogen-Propane Mixtures in a Commercial Hot-Wall CVD Reactor

2007 ◽  
Vol 556-557 ◽  
pp. 513-516 ◽  
Author(s):  
Kok Keong Lew ◽  
Brenda L. VanMil ◽  
Rachael L. Myers-Ward ◽  
Ronald T. Holm ◽  
Charles R. Eddy ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Partial Pressure ◽  
Growth Temperature ◽  
Chemical Vapor ◽  
Surface Damage ◽  
Step Bunching ◽  
Force Microscopy ◽  
Atomic Force ◽  
Stepped Surface ◽  
Higher Temperature

Hydrogen etching of 4H-SiC has been performed in a hot-wall chemical vapor deposition reactor to reduce surface damage and to create a bilayer-stepped surface morphology, optimal for initiation of growth on 4H-SiC substrates offcut 4° and 8° towards the <11-20> direction. To understand how step bunching evolves during the ramp to growth temperature, samples were etched ending at temperatures from 1400 to 1580°C under 0, 2 or 10 sccm of propane (C3H8) addition to hydrogen. Initial exploratory growth of 5 μm thick epilayers on the 4° etched surfaces are also discussed. Atomic force microscopy (AFM) and Nomarski microscopy were employed to investigate changes in the surface morphology. The 8° substrates subjected to H2-C3H8 etching up to growth temperature routinely exhibited bilayer steps. However, when the 4° substrates were etched with a 10 sccm C3H8 flow, considerable step bunching was observed. At 1450°C, with a 10 sccm of C3H8 flow (partial pressure is 1.25x10-5 bar), step bunching started with the formation of ribbon-like steps. Progression to higher temperature etches have shown the coalescence of the ribbons into larger macro-steps up to 30 nm in height. Etching 4° substrates under 2 sccm of C3H8 (partial pressure is 2.5x10-6 bar) or in pure H2 up to 1500°C results in minimal step bunching.

Preparation of Pure Anatase TiO2 Thin Films by DC Sputtering Technique: Study on the Effect of Oxygen Partial Pressure

2012 ◽  
Vol 463-464 ◽  
pp. 1415-1419 ◽  
Author(s):  
P. Pungboon Pansila ◽  
Nirun Witit-Anun ◽  
Tongsai Jamnongkan ◽  
Surasing Chaiyakun
Keyword(s):  
Thin Films ◽  
Titanium Dioxide ◽  
Surface Morphology ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Force Microscopy ◽  
Atomic Force ◽  
Sputtering Power ◽  
Effect Of Oxygen ◽  
Titanium Dioxide Thin Films

Titanium dioxide thin films were deposited by DC reactive magnetron sputtering on silicon wafer and glass slide at sputtering power of 210 watt under total pressure of 5.0×10-3 mbar at different oxygen partial pressure. A pure metallic titanium target was sputtered in a mixture of argon and oxygen gases. The crystal structure and surface morphology were characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively. The optical transmission was measured by spectrophotometer. The results show that the crystalline was pure anatase structure titanium dioxide thin films. The surface morphology of the films is strongly the oxygen partial pressure. It was found that surface roughness of the thin films was around 2.42 to 4.82 nm and the thickness was around 72 to130 nm. In addition, it was found that all the titanium dioxide thin films were deposited by reactive sputtering with the different oxygen pressure exhibit the transparency property.

Step Flow Surface Morphology in Plasma Assisted Molecular Beam Epitaxy Grown GaN

2000 ◽  
Vol 639 ◽  
Author(s):  
Kazuhide Kusakabe ◽  
Akihiko Kikuchi ◽  
Katsumi Kishino
Keyword(s):  
Molecular Beam Epitaxy ◽  
Surface Morphology ◽  
Driving Force ◽  
Molecular Beam ◽  
Chemical Vapor ◽  
Force Microscopy ◽  
Atomic Force ◽  
Flow Surface ◽  
Migration Enhanced Epitaxy ◽  
Surface Morphologies

ABSTRACTThe surface morphologies of homoepitaxial GaN films grown by molecular beam epitaxy (MBE) on metalorganic chemical vapor deposition (MOCVD) grown GaN template layers were investigated, using atomic force microscopy (AFM). Typical surface morphology of MBE-grown films on MOCVD-templates was dominated by spiral hillocks due to the high density of dislocations having a screw character and large driving force of MBE growth. Introduction of the AlN multiple interlayer (AlN -MIL) into MBE-GaN layers suppressed the formation of spiral hillocks. It was attributed to obstructing the dislocation propagation by AlN-MIL. Migration enhanced epitaxy (MEE) growth of GaN also reduced the density and tightness of spiral hillocks. This observation was attributed to that MEE growth technique decreased the driving force of growth.

scholarly journals Diamond Films for Implantable Electrodes

10.14311/1638 ◽  
2012 ◽  
Vol 52 (5) ◽  
Author(s):  
Petra Henychová ◽  
Klára Hiřmanová ◽  
Martin Vraný
Keyword(s):  
Growth Rate ◽  
Surface Morphology ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Diamond Growth ◽  
Force Microscopy ◽  
Atomic Force ◽  
Boron Doped ◽  
Implantable Electrodes ◽  
Average Size

Diamond is a promising material for implantable electrodes due to its unique properties. The aim of this work is to investigate the growth of boron-doped nanocrystalline diamond (B-NCD) films by plasma-enhanced microwave chemical vapor deposition at various temperatures, and to propose optimal diamond growth conditions for implantable electrodes. We have investigated the temperature dependence (450 °C–820 °C) of boron incorporation, surface morphology and growth rate on a polished quartz plate. Surface morphology and thickness were examined by atomic force microscopy (AFM).The quality of the films in terms of diamond and non-diamond phase of carbon was investigated by Raman spectroscopy. AFM imaging showed that the size of the grains was determined mainly by the thickness of the films, and varied from an average size of 40 nm in the lowest temperature sample to an average size of 150 nm in the sample prepared at the highest temperature. The surface roughness of the measured samples varied between 10 (495 °C) and 25 nm (800 °C). The growth rate of the sample increased with temperature. We found that the level of boron doping was strongly dependent on temperature during deposition. An optimal B-NCD sample was prepared at 595 °C.

Reduction of Dislocation Density of SiC Crystals Grown on Seeds after H2 Etching

2017 ◽  
Vol 897 ◽  
pp. 19-23 ◽  
Author(s):  
Xiu Fang Chen ◽  
Fu Sheng Zhang ◽  
Xiang Long Yang ◽  
Yan Peng ◽  
Xue Jian Xie ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Surface Morphology ◽  
Surface Damage ◽  
Subsurface Damage ◽  
Bulk Crystals ◽  
Force Microscopy ◽  
Seed Surface ◽  
Atomic Force ◽  
Order Of Magnitude ◽  
Band Contrast

Three-inch 6H-SiC bulk crystals were grown by the PVT method on the seeds processed by different treatments. The influences of seed surface morphology and subsurface damage on the dislocation density were investigated. The seed surface morphology was characterized by atomic force microscopy (AFM). The extent of the subsurface damage was estimated by electron back-scattered diffraction (EBSD) and Band Contrast (BC) value. The distribution and density of the dislocations were observed by optical microscopy (OM). The results showed that the pit density performed by H2 1400°C etching was nearly one order of magnitude lower than that by mechanical polishing (MP) process. So H2 etching processed at 1400°C for 2h could completely remove the subsurface damage, compared with the MP process with the deep surface damage.

Correlation between Extended Defects and Surface Morphology in MBE Grown InAs/GaAs Heterostructures

1995 ◽  
Vol 399 ◽  
Author(s):  
M.R. Bruni ◽  
G. Padeletti ◽  
M.G. Simeone ◽  
L. Francesio ◽  
P. Franzosi ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Growth Temperature ◽  
Crystal Defects ◽  
Extended Defects ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Gaas Substrates ◽  
Transmission Electron

ABSTRACTInAs single layers were grown by Molecular Beam Epitaxy on nominally (001) oriented GaAs substrates at growth temperatures ranging from 350 °C to 500 °C and thicknesses between 1 nm and 6 μm. A systematic study of the influence of growth temperature and thickness on crystal defects and surface morphology is discussed by comparing High Resolution X-Ray Diffraction, Transmission Electron Microscopy and Atomic Force Microscopy investigations.Surface hexagonal shaped holes were observed to develop at the lowest temperatures starting from an heterolayer thickness of 50 nm. Both misfit and threading dislocations were revealed; moreover the correlation between hexagonal shaped surface holes and mixed dislocations, with the component of the Burgers vector (b) along the growth axis larger than the minimum interatomic distance, is discussed. The holes increase in size and decrease in density by increasing the layer thickness. An almost complete surface planarization is observed at a thickness of 6 μm by increasing the growth temperature up to 500 °C.

Growth temperature - phase stability relation in In1-xGaxN epilayers grown by high-pressure CVD

2009 ◽  
Vol 1202 ◽  
Author(s):  
Goksel Durkaya ◽  
Mustafa Alevli ◽  
Max Buegler ◽  
Ramazan Atalay ◽  
Sampath Gamage ◽  
...  
Keyword(s):  
High Pressure ◽  
Phase Stability ◽  
Growth Temperature ◽  
Single Phase ◽  
Chemical Vapor ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Pressure Chemical

AbstractThe influence of the growth temperature on the phase stability and composition of single-phase In1-xGaxN epilayers has been studied. The In1-xGaxN epilayers were grown by high-pressure Chemical Vapor Deposition with nominally composition of x = 0.6 at a reactor pressure of 15 bar at various growth temperatures. The layers were analyzed by x-ray diffraction, optical transmission spectroscopy, atomic force microscopy, and Raman spectroscopy. The results showed that a growth temperature of 925°C led to the best single phase InGaN layers with the smoothest surface and smallest grain areas

Changes in Surface Morphology, Deflection and Wear of Microcrystalline Diamond Film Observed during Sliding Tests against Si3N4 Balls

2016 ◽  
Vol 674 ◽  
pp. 145-151 ◽  
Author(s):  
Andrei Bogatov ◽  
Rainer Traksmaa ◽  
Vitali Podgursky
Keyword(s):  
Surface Morphology ◽  
Diamond Film ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Chemical Vapor ◽  
Force Microscopy ◽  
Atomic Force ◽  
Test Conditions ◽  
Sliding Test ◽  
Si Wafer

The study investigates alterations in surface morphology of microcrystalline diamond (MCD) film under reciprocating sliding test conditions. The MCD film was grown by microwave plasma enhanced chemical vapor deposition (MW-PECVD) on (100)-oriented Si wafer. The surface morphology was characterized by optical microscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM) and mechanical profilometry. The formation of ripples on the wear scar surfaces was observed. The normalized wear rate (mm3/mN) of diamond film was evaluated using different approaches in order to understand the influence of diamond film deflection to wear.

Etching Treatment Effect on Surface Morphology of Dental Structures

2017 ◽  
Vol 68 (11) ◽  
pp. 2700-2703 ◽  
Author(s):  
Kamel Earar ◽  
Vasile Iulian Antoniac ◽  
Sorana Baciu ◽  
Simion Bran ◽  
Florin Onisor ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Surface Morphology ◽  
Phosphoric Acid ◽  
Human Teeth ◽  
Strong Bond ◽  
Force Microscopy ◽  
Atomic Force ◽  
Human Dentine ◽  
Dental Surface ◽  
Scanning Electron

This study examined and compared surface of human dentine after acidic etching with hydrogen peroxide, phosphoric acid liquid and gel. Surface demineralization of dentin is necessary for a strong bond of adhesive at dental surface. Split human teeth were used. After application of mentioned substances at dentin level measures of the contact angle and surface morphology were employed. Surface morphology was analyzed with the help of scanning electron microscopy and atomic force microscopy. Liquid phosphoric acid yielded highest demineralization showing better hydrophobicity than the rest, thus having more contact surface. Surface roughness are less evident and formed surface micropores of 4 �m remained open after wash and air dry providing better adhesive canalicular penetration and subsequent bond.

scholarly journals Influence of Growth Temperature of the Nucleation Layer on the Growth of InP on Si (001)

Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 823
Author(s):  
Shizheng Yang ◽  
Hongliang Lv ◽  
Likun Ai ◽  
Fangkun Tian ◽  
Silu Yan ◽  
...  
Keyword(s):  
Growth Temperature ◽  
Wafer Level ◽  
X Ray Diffraction ◽  
Nucleation Layer ◽  
Force Microscopy ◽  
Gas Source ◽  
Atomic Force ◽  
Growth Method ◽  
Step Growth ◽  
Microscopy Images

InP layers grown on Si (001) were achieved by the two-step growth method using gas source molecular beam epitaxy. The effects of growth temperature of nucleation layer on InP/Si epitaxial growth were investigated systematically. Cross-section morphology, surface morphology and crystal quality were characterized by scanning electron microscope images, atomic force microscopy images, high-resolution X-ray diffraction (XRD), rocking curves and reciprocal space maps. The InP/Si interface and surface became smoother and the XRD peak intensity was stronger with the nucleation layer grown at 350 °C. The Results show that the growth temperature of InP nucleation layer can significantly affect the growth process of InP film, and the optimal temperature of InP nucleation layer is required to realize a high-quality wafer-level InP layers on Si (001).

Surface morphology of As-deposited and laser-damaged dielectric mirror coatings studied in-situ by atomic force microscopy

1992 ◽  
Author(s):  
Mark R. Kozlowski ◽  
Michael C. Staggs ◽  
Mehdi Balooch ◽  
Robert J. Tench ◽  
Wigbert J. Siekhaus
Keyword(s):  
Atomic Force Microscopy ◽  
Surface Morphology ◽  
Force Microscopy ◽  
Dielectric Mirror ◽  
Atomic Force
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