Characterization of homoepitaxial diamond films by Electron microscopy

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).

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Comparative fractography of chemical vapor and combustion deposited diamond films

Journal of Materials Research ◽

10.1557/jmr.1990.2572 ◽

1990 ◽

Vol 5 (11) ◽

pp. 2572-2588 ◽

Cited By ~ 10

Author(s):

H. A. Hoff ◽

A. A. Morrish ◽

J. E. Butler ◽

B. B. Rath

Keyword(s):

Electron Microscopy ◽

Diamond Films ◽

Stacking Faults ◽

Chemical Vapor ◽

Polycrystalline Diamond ◽

Ambient Atmosphere ◽

Transmission Electron ◽

Controlled Environments ◽

Inherent Strength ◽

Low Pressures

Polycrystalline diamond films of several thicknesses have been fractured by manual bending and examined by scanning electron microscopy. These films have been deposited in controlled environments at low pressures by chemical vapor deposition and in ambient atmosphere with an oxygen-acetylene torch. Fracture surfaces in the low pressure depositions exhibit cleavage steps across the grains. These surfaces, independent of thickness, are primarily transgranular, attesting to the inherent strength of the deposits. However, the ambient deposited diamond has primarily intergranular fracture indicative of weak grain boundaries. Internal defects, observed with transmission electron microscopy, such as twins, stacking faults, and dislocations, occur generally in both types of deposition with no apparent preference for location or type of deposition.

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Microstructure of polycrystalline diamond film

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100176678 ◽

1990 ◽

Vol 48 (4) ◽

pp. 708-709

Author(s):

M. G. Burke ◽

R. E. Witkowski ◽

R. T. Blackham

Keyword(s):

Electron Microscopy ◽

Diamond Film ◽

Microwave Plasma ◽

Plasma Deposition ◽

Analytical Electron Microscopy ◽

Diamond Films ◽

Chemical Vapor ◽

Polycrystalline Diamond ◽

Optical Systems ◽

Power Sources

Diamond films have attracted considerable attention for use in a wide variety of industrial and commercial applications, particularly as coatings. Diamond coatings will enhance the performance of electro-optical systems, space-based photovoltaic power sources, packages for power electronic devices, and wear-limited processing equipment. These films are generally grown via plasma deposition or chemical vapor deposition techniques using a mixture. To characterize the as-grown diamond films, a variety of techniques including transmission electron microscopy are utilized. For this study, films were grown in a 1.5 kW ASTeX High Pressure Microwave Plasma Source equipped with an austenitic stainless steel, quartz lined reaction chamber. The plasma was a mixture of 0.5 or 2.0% CH4 in H2 at a reactor pressure of 30-50 mm Hg. During deposition, the substrate was heatea to ∼900-950°C. It has been reported that variations in the growth conditions will markedly affect the microstructure of the diamond film; several film morphologies have been observed. The quality of the substrate also exerts a strong effect on the nucleation of the diamond. In this on-going study, the influence of film thickness on the microstructure of polycrystalline diamond films has been characterized by analytical electron microscopy.

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CHARACTERISTICS OF HF CVD DIAMOND THIN FILMS ON CEMENTED CARBIDES

Surface Review and Letters ◽

10.1142/s0218625x07009529 ◽

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.

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Improvement in Gate Dielectric Quality of Ultra Thin a: SiN:H MNS Capacitor by Hydrogen Etching of the Substrate

MRS Proceedings ◽

10.1557/proc-716-b4.8 ◽

2002 ◽

Vol 716 ◽

Author(s):

Parag C. Waghmare ◽

Samadhan B. Patil ◽

Rajiv O. Dusane ◽

V.Ramgopal Rao

Keyword(s):

Silicon Nitride ◽

Gate Dielectric ◽

Substrate Surface ◽

Scaling Limit ◽

Tunneling Current ◽

Chemical Vapor ◽

Poor Performance ◽

State Density ◽

Direct Tunneling Current

AbstractTo extend the scaling limit of thermal SiO2, in the ultra thin regime when the direct tunneling current becomes significant, members of our group embarked on a program to explore the potential of silicon nitride as an alternative gate dielectric. Silicon nitride can be deposited using several CVD methods and its properties significantly depend on the method of deposition. Although these CVD methods can give good physical properties, the electrical properties of devices made with CVD silicon nitride show very poor performance related to very poor interface, poor stability, presence of large quantity of bulk traps and high gate leakage current. We have employed the rather newly developed Hot Wire Chemical Vapor Deposition (HWCVD) technique to develop the a:SiN:H material. From the results of large number of optimization experiments we propose the atomic hydrogen of the substrate surface prior to deposition to improve the quality of gate dielectric. Our preliminary results of these efforts show a five times improvement in the fixed charges and interface state density.

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Examination of the material properties and performance of thin-diamond film cutting tool inserts produced by arc-jet and hot filament chemical vapor deposition

Journal of Materials Research ◽

10.1557/jmr.1996.0221 ◽

1996 ◽

Vol 11 (7) ◽

pp. 1765-1775 ◽

Cited By ~ 17

Author(s):

James M. Olson ◽

Michael J. Dawes

Keyword(s):

Wear Resistance ◽

Chemical Vapor Deposition ◽

Diamond Film ◽

Vapor Deposition ◽

Cutting Tool ◽

Diamond Films ◽

Chemical Vapor ◽

Polycrystalline Diamond ◽

And Performance ◽

Hot Filament

Thin diamond film coated WC-Co cutting tool inserts were produced using arc-jet and hot-filament chemical vapor deposition. The diamond films were characterized using SEM, XRD, and Raman spectroscopy to examine crystal structure, fracture mode, thickness, crystalline orientation, diamond quality, and residual stress. The performance of the tools was evaluated by comparing the wear resistance of the materials to brazed polycrystalline diamond-tipped cutting tool inserts (PCD) while machining A390 aluminum (18% silicon). Results from the experiments carried out in this study suggest that the wear resistance of the thin diamond films is primarily related to the grain boundary strength, crystal orientation, and the density of microdefects in the diamond film.

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The effect of pressure on growth rate and quality of diamond films prepared by microwave plasma chemical vapor deposition

Acta Physica Sinica ◽

10.7498/aps.56.7183 ◽

2007 ◽

Vol 56 (12) ◽

pp. 7183

Author(s):

物理学报

Keyword(s):

Growth Rate ◽

Chemical Vapor Deposition ◽

Vapor Deposition ◽

Microwave Plasma ◽

Diamond Films ◽

Chemical Vapor ◽

Plasma Chemical ◽

Plasma Chemical Vapor Deposition ◽

Effect Of Pressure

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Optical Characterization of Chemical Vapor Deposited Large-grained Polycrystalline Diamond Films by Raman and Infrared Spectroscopy

ACTA PHOTONICA SINICA ◽

10.3788/gzxb20114010.1509 ◽

2011 ◽

Vol 40 (10) ◽

pp. 1509-1513

Author(s):

顾利萍 GU Li-ping ◽

唐春玖 TANG Chun-jiu

Keyword(s):

Infrared Spectroscopy ◽

Diamond Films ◽

Chemical Vapor ◽

Polycrystalline Diamond ◽

Optical Characterization ◽

Chemical Vapor Deposited ◽

Raman And Infrared Spectroscopy

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THE DEPOSITION AND CONTROL OF SELF ASSEMBLED SILICON NANO ISLANDS ON CRYSTALLINE SILICON

International Journal of High Speed Electronics and Systems ◽

10.1142/s0129156408005862 ◽

2008 ◽

Vol 18 (04) ◽

pp. 901-910

Author(s):

RAGNAR KIEBACH ◽

ZHENRUI YU ◽

MARIANO ACEVES-MIJARES ◽

DONGCAI BIAN ◽

JINHUI DU

Keyword(s):

Electron Microscopy ◽

Integrated Circuit ◽

Crystalline Silicon ◽

Substrate Surface ◽

Chemical Vapor ◽

High Density ◽

Transmission Electron ◽

Pressure Chemical ◽

And Control ◽

Circuit Technology

The formation of nano sized Si structures during the annealing of silicon rich oxide (SRO) films was investigated. These films were synthesized by low pressure chemical vapor deposition (LPCVD) and used as precursors, a post-deposition thermal annealing leads to the formation of Si nano crystals in the SiO 2 matrix and Si nano islands ( Si nI ) at c-Si /SRO interface. The influences of the excess Si concentration, the incorporation of N in the SRO precursors, and the presence of a Si concentration gradient on the Si nI formation were studied. Additionally the influence of pre-deposition substrate surface treatments on the island formation was investigated. Therefore, the substrate surface was mechanical scratched, producing high density of net-like scratches on the surface. Scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) were used to characterize the synthesized nano islands. Results show that above mentioned parameters have significant influences on the Si nIs . High density nanosized Si islands can epitaxially grow from the c-Si substrate. The reported method is very simple and completely compatible with Si integrated circuit technology.

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