Morphology Of Silicon Oxides On Silicon Carbide

1997 ◽  
Vol 483 ◽  
Author(s):  
M. L. O‘Brien ◽  
S. Pejdo ◽  
R. J. Nemanich

AbstractThe development of high power devices based on silicon carbide requires a more complete understanding of the oxide formation process and interface characteristics. By using an integrated UHV system, samples were cleaned and oxides deposited in situ. The approach of the oxide formation process was to form the initial insulator, a few angstroms thick, and then deposit an oxide. Various deposition techniques are used in the oxide growth process; both thermal and plasma enhanced chemical vapor deposition were employed with two different precursors (oxygen and nitrous oxide), and the results were compared with thermal oxidation. The morphology of each of the deposited oxides was compared to the bare substrate and the thermal oxide wafers. This study focuses on the morphology of the different deposition processes using AFM. Examination of the morphology of the initial insulator growth process and the oxide deposition process gives insight into the physical characteristics of the silicon dioxide deposited on silicon carbide. The RMS values of the initial insulator formation and the control wafers are 0.93 and 0.95 nm respectively. Meanwhile, the RMS values for PECVD (200–400°C) and thermal CVD (400–600°C for oxygen-silane and 800–1000°C for nitrous oxide-silane) range from 1.43 to 1.93 nm.

1991 ◽  
Vol 250 ◽  
Author(s):  
Mark D. Allendorf ◽  
Carl F. Melius

AbstractEquilibrium calculations are reported for conditions typical of silicon carbide (SiC) deposition from mixtures of silane and hydrocarbons. Included are 34 molecules containing both silicon and carbon, allowing an assessment to be made of the importance of organosilicon species (and organosilicon radicals in particular) to the deposition process. The results are used to suggest strategies for improved operation of SiC CVD processes.


2017 ◽  
Vol 8 ◽  
pp. 1250-1256 ◽  
Author(s):  
Meike Koenig ◽  
Joerg Lahann

In recent years much work has been conducted in order to create patterned and structured polymer coatings using vapor deposition techniques – not only via post-deposition treatment, but also directly during the deposition process. Two-dimensional and three-dimensional structures can be achieved via various vapor deposition strategies, for instance, using masks, exploiting surface properties that lead to spatially selective deposition, via the use of additional porogens or by employing oblique angle polymerization deposition. Here, we provide a concise review of these studies.


2011 ◽  
Vol 679-680 ◽  
pp. 67-70 ◽  
Author(s):  
Andrea Canino ◽  
Massimo Camarda ◽  
Francesco La Via

Spatially resolved micro-photoluminescence has been used to study the Single Shockley faults surface density and properties on 4H-SiC epitaxial layers. The improvement of quality of epitaxial layers due to the chemical vapor deposition process has been studied by measuring the reduction of mean density of Single Shockley faults. The change of faults density has been correlated to the different precursor gas used for the growth. In fact trichlorosilane has been used instead of silane. The change of precursor led to two different advantages: the reduction of basal plane dislocation surface density and the capability to increase the growth rate of the process. Both these features allow reducing the density of Single Shockley faults.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Nicolo' Chiodarelli ◽  
Cigang Xu ◽  
Olivier Richard ◽  
Hugo Bender ◽  
Alexander Klekachev ◽  
...  

Graphene and carbon nanotubes (CNTs) are both carbon-based materials with remarkable optical and electronic properties which, among others, may find applications as transparent electrodes or as interconnects in microchips, respectively. This work reports on the formation of a hybrid structure composed of a graphitic carbon layer on top of vertical CNT in a single deposition process. The mechanism of deposition is explained according to the thickness of catalyst used and the atypical growth conditions. Key factors dictating the hybrid growth are the film thickness and the time dynamic through which the catalyst film dewets and transforms into nanoparticles. The results support the similarities between chemical vapor deposition processes for graphene, graphite, and CNT.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Bailey Moore ◽  
Ebrahim Asadi ◽  
Gladius Lewis

A review of current deposition processes is presented as they relate to osseointegration of metallic bone implants. The objective is to present a comprehensive review of different deposition processes used to apply microstructured and nanostructured osteoconductive coatings on metallic bone implants. Implant surface topography required for optimal osseointegration is presented. Five of the most widely used osteoconductive coating deposition processes are reviewed in terms of their microstructure and nanostructure, usable thickness, and cost, all of which are summarized in tables and charts. Plasma spray techniques offer cost-effective coatings but exhibit deficiencies with regard to osseointegration such as high-density, amorphous coatings. Electrodeposition and aerosol deposition techniques facilitate the development of a controlled-microstructure coating at a similar cost. Nanoscale physical vapor deposition and chemical vapor deposition offer an alternative approach by allowing the coating of a highly structured surface without significantly affecting the microstructure. Various biomedical studies on each deposition process are reviewed along with applicable results. Suggested directions for future research include further optimization of the process-microstructure relation, crystalline plasma spray coatings, and the deposition of discrete coatings by additive manufacturing.


2020 ◽  
Vol 10 (17) ◽  
pp. 6090
Author(s):  
Daidong Guo ◽  
Ningning Cai ◽  
Guoping Wu ◽  
Fangmin Xie ◽  
Shouhong Tan ◽  
...  

Polycrystalline diamond (PCD)-coated mechanical seal rings were prepared by hot filament chemical vapor deposition (HFCVD) on graphite-loaded silicon carbide (GSiC) substrates. From the initial deposition process, the diamond first nucleated and then grew into a dense coating with grain size of 4 μm and thickness of 12.3 μm. The well-grown PCD coating, as confirmed by Raman spectroscopy and X-ray diffractometry, significantly improves the pressure–velocity limit of the mechanical seal applied in harsh operating conditions, no matter whether for a hard-to-soft mating combination or a hard-to-hard mating combination. Comparing GSiC against sintered silicon carbide (SSiC) combination (GSiC/SSiC), GSiC against graphite combination (GSiC/graphite) and PCD against graphite combination (PCD/graphite), PCD against SSiC combination (PCD/SSiC) shows the highest pressure velocity (PV) limit of 42.31 MPa·m/s with 4 kN loading at 4500 rpm rotation speed. An extremely low and stable friction coefficient and super mechanical properties under harsh conditions can be approved as the source of the high PV limit of PCD coating. A mechanical seal with PCD coating can be used for more demanding applications.


1994 ◽  
Vol 9 (1) ◽  
pp. 104-111 ◽  
Author(s):  
Ching Yi Tsai ◽  
Seshu B. Desu ◽  
Chien C. Chiu

The kinetics of silicon carbide (SiC) deposition, in a hot-wall chemical vapor deposition (CVD) reactor, were modeled by analyzing our own deposition rate data as well as reported results. In contrast to the previous attempts which used only the first order lumped reaction scheme, the present model incorporates both homogeneous gas phase and heterogeneous surface reactions. The SiC deposition process was modeled using the following reactions: (i) gas phase decomposition of methyltrichlorosilane (MTS) molecules into two major intermediates, one containing silicon and the other containing carbon, (ii) adsorption of the intermediates onto the surface sites of the growing film, and (iii) reaction of the adsorbed intermediates to form silicon carbide. The equilibrium constant for the gas phase decomposition process was divided into the forward and backward reaction constants as 2.0 × 1025 exp[(448.2 kJ/mol)/RT] and 1.1 × 1032 exp[(-416.2 kJ/mol)/RT], respectively. Equilibrium constants for the surface adsorption reactions of silicon-carrying and carbon-carrying intermediates are 0.5 × 1011 exp[(-21.6 kJ/mol)/RT] and 7.1 × 109 exp[(-33.1 kJ/mol)/RT], while the rate constant for the surface reaction of the intermediates is 4.6 × 105 exp[(-265.1 kJ/mol)/RT].


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