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Journal ArticleDOI

Effect of thermal annealing on the structural, optical and microstructural properties of a-SiC thin films

29 May 2019-Advances in Materials and Processing Technologies (Taylor & Francis)-Vol. 5, Iss: 3, pp 438-444
TL;DR: In this article, a host matrix of silicon carbide SiC is used for high band gap dielectrics for solar cells applications, where silicon nanocrystals in the host matrix are used to form Si-NCs.
Abstract: )Silicon nanocrystals in a host matrix of silicon carbide SiC are important to high band gap dielectrics for solar cells applications. Forming Si-NC is difficult considering that SiC nano-c...
Citations
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Journal Article
TL;DR: Effective nanophase segregation at a low hydrogen dilution ratio of 4.0 leads to the formation of highly uniform Si QDs embedded in the amorphous SiC matrix, which is highly relevant to the development of next-generation photovoltaic solar cells, light-emitting diodes, thin-film transistors, and other applications.
Abstract: Nanophase nc-Si/a-SiC films that contain Si quantum dots (QDs) embedded in an amorphous SiC matrix were deposited on single-crystal silicon substrates using inductively coupled plasma-assisted chemical vapor deposition from the reactive silane and methane precursor gases diluted with hydrogen at a substrate temperature of 200 °C. The effect of the hydrogen dilution ratio X (X is defined as the flow rate ratio of hydrogen-to-silane plus methane gases), ranging from 0 to 10.0, on the morphological, structural, and compositional properties of the deposited films, is extensively and systematically studied by scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, Raman spectroscopy, Fourier-transform infrared absorption spectroscopy, and X-ray photoelectron spectroscopy. Effective nanophase segregation at a low hydrogen dilution ratio of 4.0 leads to the formation of highly uniform Si QDs embedded in the amorphous SiC matrix. It is also shown that with the increase of X, the crystallinity degree and the crystallite size increase while the carbon content and the growth rate decrease. The obtained experimental results are explained in terms of the effect of hydrogen dilution on the nucleation and growth processes of the Si QDs in the high-density plasmas. These results are highly relevant to the development of next-generation photovoltaic solar cells, light-emitting diodes, thin-film transistors, and other applications.

95 citations

Journal Article
TL;DR: In this paper, the structural and optical properties of the deposited films are systematically investigated by Raman spectroscopy, x-ray diffraction, Fourier transform infrared absorption spectrographs, UV/vis spectrograms, scanning electron microscopy and high-resolution transmission electron microscopes.
Abstract: Silicon thin films with a variable content of nanocrystalline phase were deposited on single-crystal silicon and glass substrates by inductively coupled plasma-assisted chemical vapor deposition using a silane precursor without any hydrogen dilution in the low substrate temperature range from 100 to 300 °C. The structural and optical properties of the deposited films are systematically investigated by Raman spectroscopy, x-ray diffraction, Fourier transform infrared absorption spectroscopy, UV/vis spectroscopy, scanning electron microscopy and high-resolution transmission electron microscopy. It is shown that the structure of the silicon thin films evolves from the purely amorphous phase to the nanocrystalline phase when the substrate temperature is increased from 100 to 150 °C. It is found that the variations of the crystalline fraction fc, bonded hydrogen content CH, optical bandgap ETauc, film microstructure and growth rate Rd are closely related to the substrate temperature. In particular, at a substrate temperature of 300 °C, the nanocrystalline Si thin films of our interest feature a high growth rate of 1.63nms-1, a low hydrogen content of 4.0at.%, a high crystalline fraction of 69.1%, a low optical bandgap of 1.55eV and an almost vertically aligned columnar structure with a mean grain size of approximately 10nm. It is also shown that the low-temperature synthesis of nanocrystalline Si thin films without any hydrogen dilution is attributed to the outstanding dissociation ability of the high-density inductively coupled plasmas and effective plasma-surface interactions during the growth process. Our results offer a highly effective yet simple and environmentally friendly technique to synthesize high-quality nanocrystalline Si films, vitally needed for the development of new-generation solar cells and other emerging nanotechnologies.

5 citations

References
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Journal ArticleDOI
TL;DR: In this article, the size control of SiO/SiO2 superlattices with an upper limit of the nanocrystal sizes of 3.8, 2.5, and 2.0 nm was investigated.
Abstract: Phase separation and thermal crystallization of SiO/SiO2 superlattices results in ordered arranged silicon nanocrystals. The preparation method which is fully compatible with Si technologies enables independent control of particle size as well as of particle density and spatial position by using a constant stoichiometry of the layers. Transmission electron microscopy investigations confirm the size control in samples with an upper limit of the nanocrystal sizes of 3.8, 2.5, and 2.0 nm without decreasing the silicon nanocrystal density for smaller sizes. The nanocrystals show a strong luminescence intensity in the visible and near-infrared region. A size-dependent blueshift of the luminescence and a luminescence intensity comparable to porous Si are observed. Nearly size independent luminescence intensity without bleaching effects gives an indirect proof of the accomplishment of the independent control of crystal size and number.

764 citations


"Effect of thermal annealing on the ..." refers background in this paper

  • ...However, the multilayer approach is like the case studied for SiO2 and Si3N4 [25,26], which also provides better control over Si-NC size....

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Journal ArticleDOI
TL;DR: Silicon carbide (SiC) is a material with very attractive properties for microsystems applications as discussed by the authors, its mechanical strength, high thermal conductivity, ability to operate at high temperatures and extreme chemical inertness in several liquid electrolytes, make SiC an attractive candidate for MEMS applications, both as structural material and as coating layer.
Abstract: Silicon carbide (SiC) is a material with very attractive properties for microsystems applications Its mechanical strength, high thermal conductivity, ability to operate at high temperatures and extreme chemical inertness in several liquid electrolytes, make SiC an attractive candidate for MEMS applications, both as structural material and as coating layer The recently reported progress in material growth and processing techniques has strengthened the potential of this material for MEMS, especially for applications requiring operation at high temperature or in severe environments Examples of SiC microsensors and microstructures are given and interesting development in both material characteristics and micromachining processes are discussed

414 citations

Book
01 Jan 2004
TL;DR: In this paper, the authors present a simulation of low-defect 3D-SiC grown on Undulant-Si (001) substrates. But the simulation is limited to 2D and 3D SiC.
Abstract: Zero- and Two-Dimensional Native Defects.- Defect Migration and Annealing Mechanisms.- Hydrogen in SiC.- Electronic Properties of Stacking Faults and Thin Cubic Inclusions in SiC Polytypes.- Principles and Limitations of Numerical Simulation of SiC Boule Growth by Sublimation.- Defect Formation and Reduction during Bulk SiC Growth.- High Nitrogen Doping During Bulk Growth of SiC.- Homoepitaxial and Heteroepitaxial Growth on Step-Free SiC Mesas.- Low-Defect 3D-SiC Grown on Undulant-Si (001) Substrates.- New Development in Hot Wall Vapor Phase Epitaxial Growth of Silicon Carbide.- Formation of SiC Thin Films by Ion Beam Synthesis.- Atomic Structure of SiC Surfaces.- The Continuum of Interface-Induced Gap States.- Contributions to the Density of Interface States in SiC MOS Structures.- Properties of Nitrided Oxides on SiC.- Hall Effect Studies of Electron Mobility and Trapping at the SiC/SiO2 Interface.- Optical Properties of SiC.- Cyclotron Resonance Studies of Effective Masses and Band Structure in SiC.- Electronic Structure of Deep Defects in SiC.- Phosphorus-Related Centers in SiC.- Hall Scattering Factor for Electrons and Holes in SiC.- Radiotracer Deep Level Transient Spectroscopy.- Vacancy Defects Detected by Positron Annihilation.- Characterization of Defects in SiC Crystals by Raman Scattering.- Characterization of Low-Dimensional Structures in SiC Using Advanced Transmission Electron Microscopy.- Synchrotron White Beam X-ray Topography and High Resolution X-ray Diffraction Studies.- Ohmic Contacts for Power Devices on SiC.- Micromachining of SiC.- Surface Preparation Techniques for SiC Wafers.- Epitaxial Growth and Device Processing of SiC on Non-Basal Planes.- SiC Power Bipolar Transistors and Thyristors.- High-Voltage SiC Devices.- Power MOSFETs in 4H-SiC.- Normally-Off Accumulation-Mode Epi-Channel Field Effect Transistor.- Development of SiC Devices for Microwave and RF Power Amplifiers.- Advances in SiC Field Effect Gas Sensors

393 citations

Journal ArticleDOI
TL;DR: In this paper, a comprehensive review of the properties of epitaxial 4H silicon carbide polytype (4H-SiC) is presented, with particular emphasis on those aspects of this material related to room, high-temperature and harsh environment ionizing radiation detector operation.
Abstract: We present a comprehensive review of the properties of the epitaxial 4H silicon carbide polytype (4H–SiC). Particular emphasis is placed on those aspects of this material related to room, high-temperature and harsh environment ionizing radiation detector operation. A review of the characterization methods and electrical contacting issues and how these are related to detector performance is presented. The most recent data on charge transport parameters across the Schottky barrier and how these are related to radiation spectrometer performance are presented. Experimental results on pixel detectors having equivalent noise energies of 144 eV FWHM (7.8 electrons rms) and 196 eV FWHM at +27 °C and +100 °C, respectively, are reported. Results of studying the radiation resistance of 4H–SiC are analysed. The data on the ionization energies, capture cross section, deep-level centre concentrations and their plausible structures formed in SiC as a result of irradiation with various particles are reviewed. The emphasis is placed on the study of the 1 MeV neutron irradiation, since these thermal particles seem to play the main role in the detector degradation. An accurate electrical characterization of the induced deep-level centres by means of PICTS technique has allowed one to identify which play the main role in the detector degradation.

247 citations