Atomistic Configurations of Diamond/Silicon Interface

1993 ◽  
Vol 317 ◽  
Author(s):  
A. S. Nandedkar ◽  
J. Narayan
Keyword(s):  
Thin Films ◽  
Diamond Films ◽  
Stacking Faults ◽  
Interatomic Potentials ◽  
Lattice Matching ◽  
Geometric Configurations ◽  
Silicon Interface ◽  
Least Energy ◽  
Poor Adhesion

ABSTRACTThe quality of diamond thin films on nondiamond substrates is often poor because of large number of defects such as dislocations, twins, stacking faults and grain boundaries. The diamond films often exhibit poor adhesion on nondiamond substrates because of large differences in interatomic potentials between the film and the substrate. The epitaxial nature of the film is determined not only by lattice matching but also by gradient in interatomic potentials across the interface. We have used computer simulations to study energetics of different geometric configurations of C / Si interfaces. The simulations predict that an C / SiC interface had the least energy and therefore the preferred interface configuration. This is in concordance with experimental deposition of C on Si which resulted in formation of an SiC layer in between C and Si.

Comparison of Ba2YCu3O7−δ thin films grown on various perovskite substrates by coevaporation

1992 ◽  
Vol 7 (10) ◽  
pp. 2650-2657 ◽  
Author(s):  
Julia M. Phillips ◽  
M.P. Siegal ◽  
R.B. van Dover ◽  
T.H. Tiefel ◽  
J.H. Marshall ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thin Films ◽  
Substrate Material ◽  
The Other ◽  
Chemical Compatibility ◽  
Lattice Matching ◽  
Structure And Morphology ◽  
High Temperature Stage ◽  
Potential Substrate

We have compared the quality of Ba2YCu3O7−δ (BYCO) films grown by the BaF2 process on (100) substrates of the perovskites LaAlO3, LaGaO3, NdAlO3, NdGaO3, LiBaF3, and SrTiO3. The films were grown by coevaporation of Y, Cu, and BaF2 followed by a two-stage anneal. The high temperature stage of the anneal, the part of the process during which the BYCO crystal structure and morphology develop, has been varied. LaAlO3 and SrTiO3 support much better films, both electrically and structurally, than the other substrates. Of the oxides, NdGaO3 supports the worst films, while films on LiBaF3 are nonconducting. These results emphasize the overriding importance of chemical compatibility in determining the suitability of a potential substrate material. Unless this criterion is satisfied, the issue of lattice matching is unimportant.

CHARACTERISTICS OF HF CVD DIAMOND THIN FILMS ON CEMENTED CARBIDES

2007 ◽  
Vol 14 (03) ◽  
pp. 451-459
Author(s):  
LIU SHA
Keyword(s):  
Thin Films ◽  
Raman Spectrum ◽  
Substrate Surface ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Chemical Quality ◽  
Etching Depth ◽  
Grain Sizes ◽  
Diamond Thin Films

Diamond films were deposited on the WC/Co alloy substrates by a hot-filament chemical vapor deposition (HF CVD) reactor after the substrate surfaces were chemically pretreated with the two-step etching method. Some characteristics as morphology, texture, adhesion, and chemical quality of the diamond coatings on WC/Co alloy substrates were investigated by means of X-ray diffractometer (XRD), scanning electron microscope (SEM), hardness tester, and Raman spectrum. The results indicate that increasing the Co content from 0.12% to 3.22% within the etching depth of 5–10 μm caused a morphology transformation from prism diamond to spherical diamond, and a texture one from a {111} orientation to a {110} orientation. The Raman spectrum shows that the spherical diamond film contains more non-diamond phases (graphite, amorphous carbon, diamond-like carbon, etc.) and has lower chemical quality of diamond films. The diamond coated grain sizes became about four to five times smaller when the deposition temperatures on the substrate surface were reduced from 900°C to 800°C. Compared with the spherical diamond films, the prism diamond films exhibit better adhesion on the WC–Co substrates. It is also observed that the microcrystalline orientation diamond thin films with grain sizes of 1–3 μm on WC–Co substrate were formed under the circumstances of lower deposition temperature and higher gas pressure, and the microcrystalline growth mechanism of diamond thin films with a preferential orientation on WC/Co alloy is discussed.

Characterization of homoepitaxial diamond films by Electron microscopy

1991 ◽  
Vol 49 ◽  
pp. 880-881
Author(s):  
D.P. Malta ◽  
S.A. Willard ◽  
R.A. Rudder ◽  
G.C. Hudson ◽  
J.B. Posthill ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Surface Defects ◽  
Substrate Surface ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Large Degree ◽  
Rf Plasma ◽  
Semiconducting Diamond

Semiconducting diamond films have the potential for use as a material in which to build active electronic devices capable of operating at high temperatures or in high radiation environments. A major goal of current device-related diamond research is to achieve a high quality epitaxial film on an inexpensive, readily available, non-native substrate. One step in the process of achieving this goal is understanding the nucleation and growth processes of diamond films on diamond substrates. Electron microscopy has already proven invaluable for assessing polycrystalline diamond films grown on nonnative surfaces.The quality of the grown diamond film depends on several factors, one of which is the quality of the diamond substrate. Substrates commercially available today have often been found to have scratched surfaces resulting from the polishing process (Fig. 1a). Electron beam-induced current (EBIC) imaging shows that electrically active sub-surface defects can be present to a large degree (Fig. 1c). Growth of homoepitaxial diamond films by rf plasma-enhanced chemical vapor deposition (PECVD) has been found to planarize the scratched substrate surface (Fig. 1b).

The observation of nano-voids in Au thin films

1987 ◽  
Vol 45 ◽  
pp. 366-367
Author(s):  
William Krakow
Keyword(s):  
Thin Films ◽  
Melting Point ◽  
Present Author ◽  
Stacking Faults ◽  
Damage Threshold ◽  
Ionic Species ◽  
Rare Gases ◽  
Chain Defects ◽  
Vacancy Chains ◽  
Au Thin Films

It has long been known that defects such as stacking faults and voids can be quenched from various alloyed metals heated to near their melting point. Today it is common practice to irradiate samples with various ionic species of rare gases which also form voids containing solidified phases of the same atomic species, e.g. ref. 3. Equivalently, electron irradiation has been used to produce damage events, e.g. ref. 4. Generally all of the above mentioned studies have relied on diffraction contrast to observe the defects produced down to a dimension of perhaps 10 to 20Å. Also all these studies have used ions or electrons which exceeded the damage threshold for knockon events. In the case of higher resolution studies the present author has identified vacancy and interstitial type chain defects in ion irradiated Si and was able to identify both di-interstitial and di-vacancy chains running through the foil.

Electron microscopic characterization of diamond thin films and substrates for diamond heteroepitaxial growth

1989 ◽  
Vol 47 ◽  
pp. 592-593
Author(s):  
J.B. Posthill ◽  
R.P. Burns ◽  
R.A. Rudder ◽  
Y.H. Lee ◽  
R.J. Markunas ◽  
...  
Keyword(s):  
Thin Films ◽  
Wide Band ◽  
Deposition Process ◽  
Heteroepitaxial Growth ◽  
Electron Microscopic ◽  
Wide Band Gap ◽  
Lattice Matching ◽  
Different Types ◽  
Diamond Thin Films

Because of diamond’s wide band gap, high thermal conductivity, high breakdown voltage and high radiation resistance, there is a growing interest in developing diamond-based devices for several new and demanding electronic applications. In developing this technology, there are several new challenges to be overcome. Much of our effort has been directed at developing a diamond deposition process that will permit controlled, epitaxial growth. Also, because of cost and size considerations, it is mandatory that a non-native substrate be developed for heteroepitaxial nucleation and growth of diamond thin films. To this end, we are currently investigating the use of Ni single crystals on which different types of epitaxial metals are grown by molecular beam epitaxy (MBE) for lattice matching to diamond as well as surface chemistry modification. This contribution reports briefly on our microscopic observations that are integral to these endeavors.

Indentation Technique to Investigate Elastic Moduli of Thin Films on Substrates

1988 ◽  
Vol 130 ◽  
Author(s):  
D. S. Stone ◽  
T. W. Wu ◽  
P.-S. Alexopoulos ◽  
W. R. Lafontaine
Keyword(s):  
Thin Film ◽  
Experimental Data ◽  
Thin Films ◽  
Closed Form ◽  
Elastic Moduli ◽  
Depth Sensing ◽  
Indentation Technique ◽  
Average Displacement ◽  
Elasticity Solutions ◽  
Poor Adhesion

AbstractClosed-form elasticity solutions are introduced, that predict the average displacement beneath square and triangular, uniformly loaded areas at the surface of a bilayer. The solutions aid in the application of depth-sensing indentation techniques for measuring thin film elastic moduli. The elasticity solutions agree closely with experimental data of Al, Si, 1 μm Al on Si, and 2 μm Cr on Si. The case of poor adhesion between the film and substrate is briefly examined.

YBa2Cu3O7 Thin Films on Polycrystalline Diamond Films with Buffer Layers

1992 ◽  
Vol 275 ◽  
Author(s):  
G. Cui ◽  
C. P. Beetz ◽  
B. A. Lincoln ◽  
P. S. Kirlin
Keyword(s):  
Thin Films ◽  
Diamond Films ◽  
Rf Sputtering ◽  
Polycrystalline Diamond ◽  
Fast Response ◽  
Buffer Layers ◽  
Multichip Modules ◽  
Ir Detectors ◽  
Ybco Films ◽  
First Time

ABSTRACTThe deposition of in-situ YBa2CU3O7-δ Superconducting films on polycrystalline diamond thin films has been demonstrated for the first time. Three different composite buffer layer systems have been explored for this purpose: (1) Diamond/Zr/YSZ/YBCO, (2) Diamond/Si3N4/YSZ/YBCO, and (3) Diamond/SiO2/YSZ/YBCO. The Zr was deposited by dc sputtering on the diamond films at 450 to 820 °C. The YSZ was deposited by reactive on-axis rf sputtering at 680 to 750 °C. The Si3N4 and SiO2 were also deposited by on-axis rf sputtering at 400 to 700 °C. YBCO films were grown on the buffer layers by off-axis rf sputtering at substrate temperatures between 690 °C and 750 °C. In all cases, the as-deposited YBCO films were superconducting above 77 K. This demonstration enables the fabrication of low heat capacity, fast response time bolometric IR detectors and paves the way for the use of HTSC on diamond for interconnect layers in multichip modules.

scholarly journals Structural and Magnetic Properties of Ni81Fe19Thin Film Grown on Si(001) Substrate via Single Graphene Layer

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Gui-fang Li ◽  
Shibin Liu ◽  
Shanglin Yang ◽  
Yongqian Du
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Vapor Deposition ◽  
Graphene Layer ◽  
Structural Investigation ◽  
Annealing Temperature ◽  
Chemical Vapor ◽  
Magnetic Thin Films ◽  
Structural And Magnetic Properties

We prepared magnetic thin films Ni81Fe19on single-crystal Si(001) substrates via single graphene layer through magnetron sputtering for Ni81Fe19and chemical vapor deposition for graphene. Structural investigation showed that crystal quality of Ni81Fe19thin films was significantly improved with insertion of graphene layer compared with that directly grown on Si(001) substrate. Furthermore, saturation magnetization of Ni81Fe19/graphene/Si(001) heterostructure increased to 477 emu/cm3with annealing temperatureTa=400°C, which is much higher than values of Ni81Fe19/Si(001) heterostructures withTaranging from 200°C to 400°C.

Dependence of Film Thickness on Properties of Al Doped ZnO Thin Films

2011 ◽  
Vol 194-196 ◽  
pp. 2305-2311
Author(s):  
Ying Ge Yang ◽  
Dong Mei Zeng ◽  
Hai Zhou ◽  
Wen Ran Feng ◽  
Shan Lu ◽  
...  
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Electrical Parameter ◽  
Substrate Surface ◽  
Rf Magnetron Sputtering ◽  
Thickness Effect ◽  
Visible Range ◽  
Glass Substrates ◽  
Doped Zno

In this study high quality of Al doped ZnO (ZAO) thin films were prepared by RF magnetron sputtering on glass substrates at room temperature in order to study the thickness effect upon their structure, electrical and optical properties. XRD results show that the films are polycrystalline and with strongly preferred (002) orientation perpendicular to substrate surface whatever the thickness is. The crystallite size was calculated by Williamson-Hall method, while it increases as the film thickness increased. The lattice stress is mainly caused by the growth process. Hall measurements revealed electrical parameter very dependent upon thickness when the thickness of ZAO film is lower than 700 nm. The resistivity decreased and the carrier concentration and Hall mobility increases as the film thickness increased. When film thickness becomes larger, only a little change in the above properties was observed. All the films have high transmittance above 90% in visible range. Red shift of the absorption edge was observed as thickness increased. The optical energy bandgap decreased from 3.41eV to 3.30 eV with the increase of film thickness.

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