Surface morphology, growth rate and quality of diamond films synthesized in hot filament CVD system under various methane concentrations

2011 ◽  
Vol 257 (20) ◽  
pp. 8420-8426 ◽  
Author(s):  
M. Ali ◽  
M. Ürgen
2000 ◽  
Vol 14 (03) ◽  
pp. 89-93
Author(s):  
SIJIN HAN ◽  
RONGCHUAN FANG ◽  
NAIGUI SHANG ◽  
YUAN LIAO ◽  
DEFEN LE ◽  
...  

The porphyritic texture of diamond films synthesized by hot filament CVD (HFCVD) is reported for the first time. The porphyritic texture has two distinct crystal habits, where phenocrysts are set in a matrix of fine grains. The morphology and quality of films were investigated by scanning electron microscopy and Raman spectroscopy. A growth model employing secondary nucleation and growth illuminates the growth mechanism of this unusual texture. We also compare the similarity and difference between Wild's and our results on the spherical shape of a multiple faceted particle, which is formed by multiple twinning.


2003 ◽  
Vol 18 (2) ◽  
pp. 296-304 ◽  
Author(s):  
N. Ali ◽  
V.F. Neto ◽  
J. Gracio

In this paper, we present results obtained from a comparison study relating to the deposition of diamond films using two processes, namely, time-modulated chemical vapor deposition (TMCVD) and conventional CVD. Polycrystalline diamond films were deposited onto silicon substrates using both hot-filament CVD and microwave plasma CVD systems. The key feature of TMCVD is that it modulates methane (CH4) flow during diamond CVD, whereas in conventional CVD the CH4 flow is kept constant throughout the deposition process. Films grown using TMCVD were smoother, harder, and displayed better quality than similar films grown using constant CH4 flow during CVD. The advantage of using TMCVD is that it promotes secondary nucleation to occur on existing diamond crystals. Pulsing CH4, consecutively, at high and low concentrations allows the depositing film to maintain its quality in terms of diamond-carbon phase. Films grown under constant CH4 flow during diamond CVD displayed a columnar growth mode, whereas with the time modulated films the growth mode was different. The mechanism of film growth during TMCVD is presented in this paper. The growth rate of films obtained using the hot filament CVD system with constant CH4 flow was higher than the growth rate of time modulated films. However, using the microwave-plasma CVD system, the effect was the contrary and the time-modulated films were grown at a higher rate. The growth rate results are discussed in terms of substrate temperature changes during TMCVD.


2011 ◽  
Vol 697-698 ◽  
pp. 454-457 ◽  
Author(s):  
T. Zhang ◽  
Jian Guo Zhang ◽  
Bin Shen ◽  
Fang Hong Sun

The substrate temperature has great influence on the growth rate and quality of diamond films by hot filament chemical vapor deposition (HFCVD). In order to deposit polycrystalline diamond films of uniform thickness over large areas and improve the growth rate of diamond films, the substrate temperature uniformity need to be further improved. Thus three-dimensional finite volume simulation has been developed to predict substrate temperature distribution, and optimize the deposition parameters like the size and arrangement of filaments which have a profound effect on the substrate temperature. Based on the simulation results, the optimum parameters of diamond deposition are found. Subsequently, experiments of depositing diamond films on silicon (100) wafers are done when the deposition parameters are fixed at optimum values gained from the simulation results. According to the results of scanning electron microscopy (SEM) and Raman spectroscopy, the thickness and quality of diamond films are homogeneous, which validate that the simulated deposition parameters are conducive to fabricate the high quality diamond films.


1996 ◽  
Vol 423 ◽  
Author(s):  
A. V. Khomich ◽  
V. I. Polyakov ◽  
P. I. Perov ◽  
V. P. Varnin ◽  
I. G. Teremetskaya ◽  
...  

AbstractThe effect of annealing in air on internal structure and optical properties of hot filament CVD nanocrystalline diamond films was investigated. Oxidation of the films lead to selective removal of intercrystallite layers with formation of highly porous structure with characteristic dimensions of several nanometers. Dramatic changes in optical transmission and Raman spectra were also observed. The origin of the two Raman spectrum maxima at 1140 and 500 cm−1 is discussed. Hydrogen absorption and desorption processes in porous diamond were studied.


1996 ◽  
Vol 423 ◽  
Author(s):  
Dong-Gu Lee ◽  
Rajiv K. Singh

AbstractWe have developed a method for <111> oriented diamond film synthesis using micron-sized diamond particles. Different size of diamond powders were electrophoretically seeded on silicon substrates using diamond suspensions in organic solvents (acetone, methanol, and ethanol). Diamond suspension in acetone was found to be the best for obtaining uniform diamond seeding by electrophoresis. The thickness of diamond seeded films was changed by varying the applied voltage to observe the effect on the orientation of diamond particles. Then diamond films were deposited by the hot filament chemical vapor deposition (HFCVD) process. A preferred orientation with <111> direction normal to the substrate was obtained for monolayer coatings. The surface morphology, crystal orientation, and quality of diamond films were investigated using scanning electron microscopy, x-ray diffractometry, and Raman spectroscopy.


1989 ◽  
Vol 28 (Part 2, No. 7) ◽  
pp. L1282-L1285 ◽  
Author(s):  
Yasutaka Takata ◽  
Kunishige Edamatsu ◽  
Toshihiko Yokoyama ◽  
Kazuhiko Seki ◽  
Masanao Tohnan ◽  
...  

2010 ◽  
Vol 16 (4-6) ◽  
pp. 127-135 ◽  
Author(s):  
Frederik Klauser ◽  
Doris Steinmüller-Nethl ◽  
Reinhard Kaindl ◽  
Erminald Bertel ◽  
Norbert Memmel

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