Structure of Carrot Defects in 4H-SiC Epilayers

Structure of the “carrot” defects in 4H-SiC homoepitaxial layers deposited by CVD has been investigated by plan-view and cross-sectional transmission x-ray topography, cross-sectional transmission electron microscopy, atomic force microscopy, and KOH etching. The carrot defects nucleate at the substrate/epilayer interface at the emergence points of threading screw dislocations propagating from the substrate. The typical defect consists of two stacking faults: one in the prismatic plane with second one in the basal plane. The faults are connected by a stair-rod dislocation with Burgers vector 1/n[10-10] with n>3 at the cross-over. The basal plane fault is of Frank-type. Carrot defects are electrically active as evidenced by contrast in EBIC images indicating enhanced carrier recombination rate. Presence of carrot defects in the p-i-n diodes results in higher pre-breakdown reverse leakage current and approximately 50% lower breakdown voltage compared to the nominal value.

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Oxidation of Silicon Implanted with High-Dose Aluminum

MRS Proceedings ◽

10.1557/proc-354-207 ◽

1994 ◽

Vol 354 ◽

Cited By ~ 2

Author(s):

Zunde Yang ◽

Honghua Du ◽

Stephen P. Withrow

Keyword(s):

Oxidation Rate ◽

Surface Region ◽

High Dose ◽

Cross Sectional ◽

X Ray ◽

Force Microscopy ◽

Selected Area Electron Diffraction ◽

Atomic Force ◽

Transmission Electron ◽

High Doses

AbstractSi (100) wafers were implanted with Al at 500°C to high doses at multi-energies and were oxidized in 1 atm flowing oxygen at 1000°–1200°C. The morphology, structure, and oxidation behavior of the implanted and oxidized Si were studied using optical microscopy, atomic force microscopy, and cross-sectional transmission electron microscopy in conjunction with selected area electron diffraction and energy dispersive x-ray analysis. Large Al precipitates were formed and embedded near the surface region of the implanted Si. The oxidation rate of the Al-implanted Si wafers was lower than that of virgin Si. The unique morphology of the implanted Si results from rapid Al diffusion and segregation promoted by hot implantation. The reduction of the oxidation rate of Si by Al implantation is attributed to the preferential oxidation of Al and formation of a continuous difiusion barrier of Al2O3.

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Microstructural Characterization of Low Temperature GaAs(111)B MBE Growth by AFM and Tem

MRS Proceedings ◽

10.1557/proc-280-631 ◽

1992 ◽

Vol 280 ◽

Author(s):

M. P. de Boer ◽

J. E. Angelo ◽

A. M. Dabiran ◽

P. I. Cohen ◽

W. W. Gerberich

Keyword(s):

Low Temperature ◽

Microstructural Characterization ◽

Cross Sectional ◽

Plan View ◽

Mbe Growth ◽

Force Microscopy ◽

Atomic Force ◽

Transmission Electron ◽

Low Temperature Gaas

ABSTRACTAtomic Force Microscopy (AFM) images are correlated with Transmission Electron Microscopy (TEM) plan-view images in a structure consisting of <111> oriented GaAs layers grown by molecular beam epitaxy (MBE) at 500°C. We present results on the applicability of AFM, which requires short sample preparation and imaging time relative to TEM, in obtaining information on twin density and growth pits of these low temperature samples. Also, we discuss the behavior of twin boundaries by comparing plan-views and cross sectional TEM images.

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Non-Destructive Characterization of Porous Silicon Using X-Ray Reflectivity

MRS Proceedings ◽

10.1557/proc-358-321 ◽

1994 ◽

Vol 358 ◽

Cited By ~ 4

Author(s):

E. Chason ◽

T.R. Guilinger ◽

M.J. Kelly ◽

T.J. Headley ◽

A.J. Howard

Keyword(s):

Porous Silicon ◽

Film Growth ◽

Interface Roughness ◽

Electrochemical Anodization ◽

Cross Sectional ◽

X Ray ◽

Force Microscopy ◽

Atomic Force ◽

Transmission Electron ◽

Constant Rate

ABSTRACTUnderstanding the evolution of porous silicon (PS) layers at the early stages of growth is important for determining the mechanism of PS film growth and controlling the film properties. We have used X-ray reflectivity (XRR) to determine the evolution of layer thickness and interfacial roughness during the growth of thin PS layers (< 200 nm) prepared by electrochemical anodization. The porous layer grows at a constant rate for films as thin as 15 nm indicating a very short incubation period during which the surface may be electropolished before the PS structure begins to form. Interface roughness measurements indicate that the top surface of the film remains relatively smooth during growth while the roughness of the PS/silicon interface increases only slightly with film thickness. The XRR results are compared with results obtained from the same films by cross-sectional transmission electron microscopy (XTEM), atomic force microscopy (AFM) and gravimetry.

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Microstructure and Physical Properties of Ferroelectric-gate Memory Capacitors with Various Buffer Layers

MRS Proceedings ◽

10.1557/proc-666-f8.5 ◽

2001 ◽

Vol 666 ◽

Author(s):

Christine Caragianis-Broadbridge ◽

Jin-ping Han ◽

T. P. Ma ◽

Ann Hein Lehman ◽

Wenjuan Zhu ◽

...

Keyword(s):

Physical Properties ◽

Photoelectron Spectroscopy ◽

Hafnium Oxide ◽

Silicon Oxide ◽

Buffer Layers ◽

Cross Sectional ◽

X Ray ◽

Force Microscopy ◽

Atomic Force ◽

Transmission Electron

ABSTRACTThis paper reports the microstructure and physical properties of ferroelectric capacitors formed from SrBi2Ta2O9(SBT) layers on Si with various buffer layers including jet-vapor deposited silicon nitride, zirconium oxide, hafnium oxide and thermally grown silicon oxide. Results from cross-sectional transmission electron microscopy (X-TEM), energy dispersive spectroscopy (EDS), X-Ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and non-contact atomic force microscopy (nc-AFM) data coupled with capacitance-voltage (C-V) and current- voltage (I-V) data indicate that both the microstructure and physical properties of SBT films deposited on silicon are dependent on the buffer layer material employed.

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Defects In 4H Silicon Carbide CVD Epilayers

MRS Proceedings ◽

10.1557/proc-442-631 ◽

1996 ◽

Vol 442 ◽

Cited By ~ 1

Author(s):

L. Zhou ◽

P. Pirouz ◽

J. A. Powell

Keyword(s):

Formation Mechanism ◽

Chemical Vapor ◽

Cross Sectional ◽

Plan View ◽

Force Microscopy ◽

Atomic Force ◽

Surface Steps ◽

Transmission Electron ◽

Surface Decoration ◽

Decoration Technique

AbstractThe characteristic defects of 4H-SiC homoepitaxial thin films grown on bulk substrates using chemical vapor deposition (CVD) are described based on transmission electron microscopy (TEM), atomic force microscopy (AFM) and surface decoration studies. Emphasis is placed on understanding the formation mechanism of surface triangular defects. Cross-sectional TEM observations revealed the existence of two variants of 3C-SiC inclusions in 4H epitaxial films. In the plan-view orientation, g4H = 3304 type reflections were found useful for distinguishing the two variants of 3C-SiC platelets that are present in the 4H epilayer. A decoration technique was employed to reveal the relationship between the 3C platelets and surface features, e.g., surface steps. A formation mechanism for surface triangular defects is proposed, which is partially confirmed by the etch pit patterns obtained on the epilayer surfaces after a molten KOH etch.

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Maskless Lateral Epitaxial Overgrowth of GaN on Sapphire

MRS Proceedings ◽

10.1557/proc-572-315 ◽

1999 ◽

Vol 572 ◽

Cited By ~ 16

Author(s):

P. Fini ◽

H. Marchand ◽

J. P. Ibbetson ◽

B. Moran ◽

L. Zhao ◽

...

Keyword(s):

Threading Dislocations ◽

X Ray Diffraction ◽

Cross Sectional ◽

Defect Reduction ◽

Lateral Epitaxial Overgrowth ◽

X Ray ◽

Force Microscopy ◽

Atomic Force ◽

Transmission Electron ◽

Crystallographic Tilt

ABSTRACTWe demonstrate a technique of lateral epitaxial overgrowth (LEO) of GaN, termed 'maskless' LEO, in which no mask is deposited prior to LEO regrowth. Instead, a bulk (> 2 μm) GaN layer on sapphire is selectively dry etched, leaving ∼5 μm-wide stripe mesas oriented in the <1010>GaN direction, with a 20 μm period. These stripes serve as seeds for LEO GaN growth, which proceeds from the tops of the stripes and expands laterally, resulting in a ‘T’, or overhang, morphology. As for LEO over an SiO2 mask, significant defect reduction (from ∼109 cm−2 to ∼106 cm−2 ) is observed in cross-sectional transmission electron microscopy (TEM). Atomic force microscopy of the top surface of the LEO GaN reveals that no threading dislocations with screw component terminate at the surfaces of laterally overgrown regions. X-ray diffraction measurements reveal that the wings exhibit a crystallographic tilt away from the seed regions in an azimuth perpendicular to the stripe direction; the tilt angle (∼0.4 – 0.5°) is relatively independent of growth temperature and wing aspect ratio.

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Curcumin delivery by modified biosourced carbon-based nanoparticles

Nanomedicine ◽

10.2217/nnm-2021-0225 ◽

2022 ◽

Author(s):

Hossein Danafar ◽

Marziyeh Salehiabar ◽

Murat Barsbay ◽

Hossein Rahimi ◽

Mohammadreza Ghaffarlou ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Free System ◽

X Ray ◽

Force Microscopy ◽

Atomic Force ◽

Transmission Electron ◽

Good Biocompatibility ◽

Drug Free ◽

Mcf 7 ◽

Carbon Based

Aim: To prepare a novel hybrid system for the controlled release and delivery of curcumin (CUR). Methods: A method for the ultrasound-assisted fabrication of protein-modified nanosized graphene oxide-like carbon-based nanoparticles (CBNPs) was developed. After being modified with bovine serum albumin (BSA), CUR was loaded onto the synthesized hybrid (labeled CBNPs@BSA–CUR). The structure and properties of the synthesized nanoparticles were elucidated using transmission electron microscopy (TEM), atomic force microscopy (AFM), ultraviolet-visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR) and x-ray photoelectron spectroscopy (XPS) methods. Results: CBNPs@BSA–CUR showed pH sensitivity and were calculated as controlled CUR release behavior. The drug-free system exhibited good biocompatibility and was nontoxic. However, CBNPs@BSA–CUR showed acceptable antiproliferative ability against MCF-7 breast cancer cells. Conclusion: CBNPs@BSA–CUR could be considered a highly promising nontoxic nanocarrier for the delivery of CUR with good biosafety.

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Direct Deposition Reactions Between Nickel and Silicon Substrates

MRS Proceedings ◽

10.1557/proc-311-335 ◽

1993 ◽

Vol 311 ◽

Author(s):

Lin Zhang ◽

Douglas G. Ivey

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Silicon Substrates ◽

Silicide Formation ◽

Cross Sectional ◽

Deposition Rates ◽

Plan View ◽

X Ray ◽

Si Substrates ◽

Transmission Electron

ABSTRACTSilicide formation through deposition of Ni onto hot Si substrates has been investigated. Ni was deposited onto <100> oriented Si wafers, which were heated up to 300°C, by e-beam evaporation under a vacuum of <2x10-6 Torr. The deposition rates were varied from 0.1 nm/s to 6 nm/s. The samples were then examined by both cross sectional and plan view transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy and electron diffraction. The experimental results are discussed in terms of a new kinetic model.

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Epitaxial BaTiO3 Thin Films on Different Substrates for Optical Waveguide Applications

MRS Proceedings ◽

10.1557/proc-597-145 ◽

1999 ◽

Vol 597 ◽

Cited By ~ 5

Author(s):

M. Siegert ◽

Judit G. Lisoni ◽

C. H. Lei ◽

A. Eckau ◽

W. Zander ◽

...

Keyword(s):

Thin Films ◽

Optical Waveguides ◽

Rutherford Backscattering Spectrometry ◽

Optical Data ◽

X Ray Diffraction ◽

X Ray ◽

Force Microscopy ◽

Ion Channeling ◽

Atomic Force ◽

Transmission Electron

AbstractIn the process of developing thin film electro-optical waveguides we investigated the influence of different substrates on the optical and structural properties of epitaxial BaTiO3 thin films. These films are grown by on-axis pulsed laser deposition (PLD) on MgO(100), MgAl2O4(100), SrTiO3(100) and MgO buffered A12O3(1102) substrates. The waveguide losses and the refractive indices were measured with a prism coupling setup. The optical data are correlated to the results of Rutherford backscattering spectrometry/ion channeling (RBS/C). X-ray diffraction (XRD), atomic force microscopy (AFM) and transmission electron microscopy (TEM). BaTiO3 films on MgO(100) substrates show planar waveguide losses of 3 dB/cm and ridge waveguide losses of 5 dB/cm at a wavelength of 633 nm.

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