In Situ Fhir Spectroscopic Detection of Adsorbed Species on Sapphire Substrates in a Diamond ECR-Pacvd System

1997 ◽  
Vol 502 ◽  
Author(s):  
F. Shahedipour ◽  
S. Zhu ◽  
H. W. White
Keyword(s):  
Electron Cyclotron Resonance ◽  
Microwave Plasma ◽  
Hydrogen Plasma ◽  
Chemical Vapor ◽  
Diamond Deposition ◽  
Diamond Nucleation ◽  
Sapphire Substrates ◽  
Film Synthesis ◽  
Deposition Conditions

ABSTRACTIn situ Fourier Transform Infrared Reflection Absorption Spectroscopy (FTIRRAS) has been used to study the adsorbed plasma species on sapphire substrate throughout the nucleation and deposition stages under diamond deposition conditions. The focus of this work has been on one of the most fundamental questions in the area of diamond film synthesis that concerns the gas species (precursors) responsible for diamond nucleation and growth especially on foreign substrates. It is experimentally shown here that the most probable precursor for diamond nucleation in methane-hydrogen plasma are methyl radicals.Diamond deposition on randomly oriented sapphire substrates has been successfully achieved under low pressure- low temperature deposition conditions using an electron cyclotron resonance microwave plasma assisted chemical vapor deposition (ECR-PACVD) system. The deposited thin films were characterized by Raman spectroscopy, and scanning electron microscopy.

Improvement in the Sensitivity of the Response of Diamond Thin Films to X-Ray

2007 ◽  
Vol 336-338 ◽  
pp. 1718-1721 ◽  
Author(s):  
Xiao Ming Liao ◽  
Jun Guo Ran ◽  
Li Gou ◽  
Jin Zhang ◽  
Bao Hui Su ◽  
...  
Keyword(s):  
Microwave Plasma ◽  
Hydrogen Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
High Sensitivity ◽  
Post Treatment ◽  
X Ray ◽  
Microwave Plasma Cvd ◽  
Higher Sensitivity

Due to some inferior performance of Chemical Vapor Deposition (CVD) diamond dosimeters, their applications are somewhat limited. The quality of diamond films was improved using Microwave Plasma CVD (MWPCVD) by the modified processes such as cyclic deposition and in-situ plasma post-treatment. The simple radiation dosimeters were fabricated in a sandwich configuration. Influence of purity and orientation of the diamond films on the sensitivity of the dosimeters was studied. The results indicate that the radiation dosimeters have high sensitivity to X-ray and the response of the devices is linear with the X-ray flux. The higher the purity of films is, the higher the resistivity and sensitivity are. The dosimeter based on [100] film has higher sensitivity than that based on [111] film. The dosimeter based on films prepared by cyclic deposition has higher sensitivity than that based on films prepared by the conventional deposition. The characterization of the response to X-ray also shows that in-situ oxygen plasma post-treatment leads to the higher sensitivity of dosimeters compared with in-situ nitrogen, hydrogen plasma post-treatments.

Diamond nucleation on unscratched silicon substrates coated with various non-diamond carbon films by microwave plasma-enhanced chemical vapor deposition

1995 ◽  
Vol 10 (1) ◽  
pp. 165-174 ◽  
Author(s):  
Z. Feng ◽  
M.A. Brewer ◽  
K. Komvopoulos ◽  
I.G. Brown ◽  
D.B. Bogy
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Hydrogen Plasma ◽  
Chemical Vapor ◽  
Carbon Films ◽  
Nucleation Density ◽  
Silicon Substrates ◽  
Hard Carbon ◽  
Diamond Nucleation

The efficacy of various non-diamond carbon films as precursors for diamond nucleation on unscratched silicon substrates was investigated with a conventional microwave plasma-enhanced chemical vapor deposition system. Silicon substrates were partially coated with various carbonaceous substances such as clusters consisting of a mixture of C60 and C70, evaporated films of carbon and pure C70, and hard carbon produced by a vacuum are deposition technique. For comparison, diamond nucleation on silicon substrates coated with submicrometer-sized diamond particles and uncoated smooth silicon surfaces was also examined under similar conditions. Except for evaporated carbon films, significantly higher diamond nucleation densities were obtained by subjecting the carbon-coated substrates to a low-temperature high-methane concentration hydrogen plasma treatment prior to diamond nucleation. The highest nucleation density (∼3 × 108 cm−2) was obtained with hard carbon films. Scanning electron microscopy and Raman spectroscopy demonstrated that the diamond nucleation density increased with the film thickness and etching resistance. The higher diamond nucleation density obtained with the vacuum are-deposited carbon films may be attributed to the inherent high etching resistance, presumably resulting from the high content of sp3 atomic bonds. Microscopy observations suggested that diamond nucleation in the presence of non-diamond carbon deposits resulted from carbon layers generated under the pretreatment conditions.

In situ growth rate measurement and nucleation enhancement for microwave plasma CVD of diamond

1992 ◽  
Vol 7 (2) ◽  
pp. 257-260 ◽  
Author(s):  
B.R. Stoner ◽  
B.E. Williams ◽  
S.D. Wolter ◽  
K. Nishimura ◽  
J.T. Glass
Keyword(s):  
Growth Rate ◽  
Microwave Plasma ◽  
Hydrogen Plasma ◽  
Diamond Particle ◽  
Chemical Vapor ◽  
Processing Parameters ◽  
Ex Situ ◽  
Particle Nucleation ◽  
Cross Sectional

Laser reflection interferometry (LRI) has been shown to be a useful in situ technique for measuring growth rate of diamond during microwave plasma chemical vapor deposition (MPCVD). Current alternatives to LRI usually involve ex situ analysis such as cross-sectional SEM or profilometry. The ability to measure the growth rate in ‘real-time’ has allowed the variation of processing parameters during a single deposition and thus the extraction of much more information in a fraction of the time. In situ monitoring of growth processes also makes it possible to perform closed loop process control with better reproducibility and quality control. Unfortunately, LRI requires a relatively smooth surface to avoid surface scattering and the commensurate drop in reflected intensity. This problem was remedied by greatly enhancing the diamond particle nucleation via the deposition of an intermediate carbon layer using substrate biasing. When an unscratched silicon wafer is pretreated by biasing negatively relative to ground while in a methane-hydrogen plasma, nucleation densities much higher than those achieved on scratched silicon wafers are obtained. The enhanced nucleation allows a complete film composed of small grains to form in a relatively short time, resulting in a much smoother surface than is obtained from a film grown at lower nucleation densities.

A Comparative Study of Nucleation Enhancement Techniques for Plasma Cvd of Diamond Thin Films

1994 ◽  
Vol 349 ◽  
Author(s):  
R.J. Meilunas ◽  
A. Tobin
Keyword(s):  
Thin Film ◽  
Microwave Plasma ◽  
Chemical Vapor ◽  
Processing Parameters ◽  
Carbon Cluster ◽  
Nucleation Density ◽  
Plasma Cvd ◽  
Diamond Nucleation ◽  
Diamond Surfaces ◽  
Dc Biasing

ABSTRACTThree methods recently proposed for enhancing the nucleation density of thin film diamond on non-diamond surfaces during microwave plasma assisted chemical vapor deposition are investigated. The results of a series of nucleation and growth studies utilizing a dc biasing technique, carbon cluster (C70) thin film overlayers, and thin film metal (Fe) overlayers for diamond nucleation enhancement are presented. The influence of the substrate and plasma processing parameters under which the above nucleation enhancement effects occur has been determined for the three respective techniques.

Material Reliability of Low-Temperature Boron Deposition for PureB Silicon Photodiode Fabrication

MRS Advances ◽  
2018 ◽  
Vol 3 (57-58) ◽  
pp. 3397-3402 ◽  
Author(s):  
L.K. Nanver ◽  
K. Lyon ◽  
X. Liu ◽  
J. Italiano ◽  
J. Huffman
Keyword(s):  
High Temperature ◽  
Layer Thickness ◽  
Vapor Deposition ◽  
Dark Current ◽  
Deposition Temperature ◽  
Chemical Vapor ◽  
Silicon Photodiode ◽  
In Situ Methods ◽  
Deposition Conditions

ABSTRACTThe chemical-vapor deposition conditions for the growth of pure boron (PureB) layers on silicon at temperatures as low as 400°C were investigated with the purpose of optimizing photodiodes fabricated with PureB anodes for minimal B-layer thickness, low dark current and chemical robustness. The B-deposition is performed in a commercially-available Si epitaxial reactor from a diborane precursor. In-situ methods commonly used to improve the cleanliness of the Si surface before deposition are tested for a deposition temperature of 450°C and PureB layer thickness of 3 nm. Specifically, high-temperature baking in hydrogen, and exposure to HCl are tested. Both material analysis and electrical diode characterization indicate that these extra cleaning steps degrade the properties of the PureB layer and the fabricated diodes.

Novel in situ production of smooth diamond films

1998 ◽  
Vol 13 (7) ◽  
pp. 1735-1737 ◽  
Author(s):  
Donald R. Gilbert ◽  
Dong-Gu Lee ◽  
Rajiv K. Singh
Keyword(s):  
Electron Cyclotron Resonance ◽  
Microwave Plasma ◽  
Ion Beam ◽  
Diamond Films ◽  
Extraction Process ◽  
Pure Oxygen ◽  
Average Roughness ◽  
Process System ◽  
Unique Method

We have developed a unique method to produce smooth diamond films using a modified microwave plasma process system. This method consists of sequential in situ deposition and planarization in an electron cyclotron resonance plasma system. Diamond films were deposited to a thickness of 3.0 μm in this system at a pressure of 1.000 Torr from gas mixtures of methanol and hydrogen. Deposition was followed by planarization using a two-grid ion beam extraction process with a pure oxygen plasma at 10 mTorr. The average roughness of the diamond films so produced was as low as 30 nm, which was a factor of two lower than that of the as-deposited diamond films.

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