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.

Movpe Strip-Like Self-Organization of InAs Grown on InP Vicinal Surfaces

2000 ◽  
Vol 618 ◽  
Author(s):  
Laurent Auvray ◽  
Véronique Soulière ◽  
Hervé Dumont ◽  
Jacques Dazord ◽  
Yves Monteil ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Growth Parameters ◽  
Flux Ratio ◽  
Growth Conditions ◽  
Thin Layers ◽  
Vicinal Surfaces ◽  
Force Microscopy ◽  
Atomic Force ◽  
Nominal Thickness ◽  
Inp Substrates

ABSTRACTWe have investigated the influence of MOVPE growth parameters on the surface morphology of InAs nanostructures grown on 0.2° misoriented (001)InP substrates. Thin layers of nominal thickness of about 3 and 6 ML were deposited at 500°C with V/Ill flux ratios ranging from 50 to 240. The samples were cool down from 500 to 350°C during 6 minutes under either arsine or phophine atmosphere. The influence of this step has been found to greatly determine the surface morphology of the nanostructures observed by atomic force microscopy. Dots self-aligned along the steps and forming a non continuous strip, regularly spaced every 3-4 terraces have been obtained. The morphology of the strips can be varied with the growth conditions (V/III flux ratio). In this work, we will propose a mechanism for the formation of the strips observed during the cooling under phosphine atmosphere taking into account an As » P exchange.

Surface morphology of {100} faces ofL-arginine phosphate monohydrate single crystals investigated by atomic force microscopy

2005 ◽  
Vol 38 (4) ◽  
pp. 657-660 ◽  
Author(s):  
Y. L. Geng ◽  
D. Xu ◽  
X. Q. Wang ◽  
G. H. Zhang ◽  
G. W. Yu ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Atomic Force Microscopy ◽  
Surface Morphology ◽  
Single Crystals ◽  
Liquid Flow ◽  
Growth Conditions ◽  
Mother Solution ◽  
Two Dimensional ◽  
Force Microscopy ◽  
Atomic Force

Surface morphology of {100} faces of LAP crystals was investigated by atomic force microscopy (AFM). Both the steps and the two-dimensional nuclei elongate along thebdirection, which is determined by the crystal structure. Fluctuations in the growth conditions could result in the formation of protuberances on the step fronts. Tree-like growth belts are initially observed on LAP crystals. It is assumed that the formation is caused by uneven liquid flow of the mother solution.

Multivariable study on homoepitaxial diamond growth using isotopically enriched carbon-13 gas mixtures

2009 ◽  
Vol 24 (2) ◽  
pp. 493-498 ◽  
Author(s):  
Gopi K. Samudrala ◽  
Yogesh K. Vohra
Keyword(s):  
Microwave Plasma ◽  
Chemical Vapor ◽  
Nitrogen Vacancy ◽  
Diamond Growth ◽  
Plasma Chemical ◽  
Rocking Curve ◽  
X Ray ◽  
Plasma Chemical Vapor Deposition ◽  
Force Microscopy ◽  
Atomic Force

We report our observations on the homoepitaxial diamond growth by microwave plasma chemical vapor deposition (MPCVD) experiments on Type Ib diamond substrates conducted by varying three independent variables. In a feed gas mixture of H2, N2, O2, and 13CH4, the amount of nitrogen was varied in the range of 0 to 4000 ppm, the amount of methane was varied from 2% CH4/H2 to 6% CH4/H2, and the substrate temperature was varied in the range of 850 to 1200 °C. We used isotopically enriched carbon-13 methane gas as the source of carbon in the plasma to clearly distinguish the grown diamond layer from the underlying substrate using Raman spectroscopy. The x-ray rocking curve measurements confirmed the homoepitaxial nature of the deposited layers with a slight increase in the full width at half-maximum for sample grown with the highest nitrogen content in the plasma. Optical and atomic force microscopy revealed dramatic changes in surface morphology with variation in each parameter. The nitrogen incorporation in carbon-13 diamond layers was monitored through photoluminescence spectroscopy of nitrogen–vacancy complexes. A twentyfold increase in diamond growth rate was clearly achieved in this multivariable study.

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.

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.

Graphene Synthesis on Specified Location

2014 ◽  
Vol 609-610 ◽  
pp. 159-164
Author(s):  
Han Zhang ◽  
Chen Xu Zhao ◽  
Xin Guo ◽  
Yan Wu Lu ◽  
Ze Wen Liu
Keyword(s):  
Thin Films ◽  
Chemical Vapor ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Conductive Atomic Force Microscopy ◽  
Force Microscopy ◽  
Graphene Synthesis ◽  
Atomic Force ◽  
Series Of Experiments ◽  
Few Layer Graphene

The synthesis of graphene using chemical vapor deposition (CVD) on patterned Cu thin films was studied. A series of experiments were carried out to optimize the CVD process of graphene synthesis on Cu thin films and the optimal growth conditions were obtained. Consequently, few-layer graphene which had been characterized by optical microscopy and Raman spectroscopy atomic was synthesized. Conductive atomic force microscopy (AFM) was used to measure the conductivity of metal-graphene contact samples and the result showed that the conductivity of CVD synthesized graphene on Cu thin films is higher than the transferred graphene on same Cu thin films, which was synthesized on 25 μm Cu foils by conventional CVD method.

Low-Pressure Chemical Vapor Deposition of Borosilicate Glasses and their Application to Wafer Bonding

1999 ◽  
Vol 587 ◽  
Author(s):  
Darren M. Hansen ◽  
Peter D. Moran ◽  
T. F. Kuech
Keyword(s):  
Wafer Bonding ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Borosilicate Glasses ◽  
Force Microscopy ◽  
Compliant Substrates ◽  
Atomic Force ◽  
Boron Doped ◽  
Plasma Surface Treatment ◽  
Pressure Chemical

AbstractThe essential features of the deposition process and the film properties of borosilicate glasses are presented here as an alternative to pure SiO2in wafer bonding and compliant substrates. While the deposition of SiO2 is a well-studied system, the deposition of boron-doped films is less understood. The deposition rate of the SiO2 mole fraction in the films was accelerated by the presence of trimethylborate and oxygen and this is associated with an increased adsorption of the tetraethylorthosilicate related precursor in the presence of boranols. Typical deposition conditions result in borosilicate glass films with an r.m.s. roughness of ∼0.5 nm as measured by atomic force microscopy. Annealing the films at temperatures above 550°C reduces the film roughness via glass reflow. Room temperature bonding of these films was achieved after a 250 WO2 plasma surface treatment. Fourier-transform infrared investigations of the bonded interface revealed the importance of the role of surface OH and H2O groups in the bonding of these films.

Experimental Investigation of the Impact of Annealing on Resistivity of Boron-Doped Hydrogenated Nanocrystalline Silicon Thin Films

2010 ◽  
Vol 29-32 ◽  
pp. 1883-1887
Author(s):  
Hai Bin Pan ◽  
Yuan Tian ◽  
Guang Gui Cheng ◽  
Li Qiang Guo
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Chemical Vapor ◽  
Nanocrystalline Silicon ◽  
Force Microscopy ◽  
Silicon Thin Films ◽  
Atomic Force ◽  
Boron Doped ◽  
The Impact ◽  
The Relationship

Boron-doped hydrogenated nanocrystalline silicon (nc-Si:H) thin films were deposited by plasma enhanced chemical vapor deposition (PECVD). Microstructures of these films were characterized and analyzed by Raman spectrum and atomic force microscopy (AFM). Thickness and resistivity of these films was measured by high-resolution profilometer and four-point probe respectively. The impact of annealing on boron-doped nc-Si:H thin films’ resistivity and the relationship between resistivity and microstructure were investigated. The results show that annealing and the annealing temperature have great impact on resistivity of nc-Si:H thin films as a result of microstructures changing after annealing. Resistivity of nc-Si:H thin films decreases after annealing, but it rises with the increasing annealing temperature in the range of 250°C to 400°C.

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.

Effect of Introducing Free Gaseous Radicals of Trichlorosilane and Ammonia Precursors on Growth and Characteristics of LPCVD a-SiNx Ultra Thin Films

2013 ◽  
Vol 829 ◽  
pp. 401-409
Author(s):  
Armin Salmasi ◽  
Eskandar Keshavarz Alamdari
Keyword(s):  
Thin Films ◽  
Growth Rate ◽  
Surface Topography ◽  
Depth Profiling ◽  
Chemical Vapor ◽  
Arrhenius Behavior ◽  
Force Microscopy ◽  
Atomic Force ◽  
Pressure Chemical ◽  
Rate Ratios

Preparation and characteristics of amorphous silicon nitride (a-SiNx) thin films deposited by low pressure chemical vapor deposition (LPCVD) are investigated. Free gaseous radicals of trichlorosilane (TCS) and ammonia (NH3) are produced by passing each of the precursor gases separately over Pt-Ir/Al2O3 catalyst at the temperature of 600 C. Kinetics studies of the LPCVD are carried out in different total pressures, NH3/TCS flow rate ratios and temperatures. Surface topography, chemical concentrations, growth rate and thickness are studied by Ellipsometry, x-ray photo-electron spectroscopy (XPS), atomic force microscopy (AFM) and auger depth profiling (ADP). Analysis of experiments indicates that at the temperatures between 730 C and 830 C, the growth rate of thin films follows an Arrhenius behavior with activation energy of 166.3 KJ.mol-1. The measured hydrogen contamination in a-SiNx ultra thin films is 1.05 at% which is 17 times lower than the corresponding contamination in the films produced by (PECVD) and 3.4 times lower than the contamination in the LPCVD thin films with silane (SiH4) or dichlorosilane (DCS) and Ammonia. The surface topography of the prepared films is smooth and uniform and the thickness varies between 23 and 101 nanometers.

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