Promoting secondary nucleation using methane modulations during diamond chemical vapor deposition to produce smoother, harder, and better quality films

2003 ◽  
Vol 18 (2) ◽  
pp. 296-304 ◽  
Author(s):  
N. Ali ◽  
V.F. Neto ◽  
J. Gracio
Keyword(s):  
Growth Rate ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Plasma Cvd ◽  
Secondary Nucleation ◽  
Microwave Plasma Cvd ◽  
Hot Filament Cvd ◽  
Hot Filament

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.

Morphology of Diamond Films Grown by DC Plasma Jet CVD

1989 ◽  
Vol 162 ◽  
Author(s):  
Kazuaki Kurihara ◽  
Ken-Ichi Sasaki ◽  
Motonobu Kawarada ◽  
Nagaaki Koshino
Keyword(s):  
Growth Rate ◽  
Microwave Plasma ◽  
Diamond Films ◽  
High Growth ◽  
Plasma Jet ◽  
High Growth Rate ◽  
Plasma Cvd ◽  
Dc Plasma ◽  
Synthesis Conditions ◽  
Microwave Plasma Cvd

ABSTRACTIt is well known that diamond films synthesized from the gas phase have well defined crystal habits which are affected strongly by synthesis conditions. Though there have been many studies of the morphologies of diamond films synthesized by microwave plasma CVD [1,2,3], there have been relatively few reports on the morphologies of these films grown using new high growth rate techniques such as DC plasma jet CVD [4]. Morphology control is very important to keep flat surface, when producing thick diamond films by high growth rate techniques. In this paper we report our investigation of the morphology and growth of diamond films synthesized by DC plasma jet CVD.

scholarly journals A Brief Review on Recent Development of Carbon Nanotubes by Chemical Vapor Deposition

2021 ◽  
Vol 4 (2) ◽  
pp. 68-71
Author(s):  
S. A. Razak ◽  
N. N. Nordin ◽  
M. A. Sulaiman ◽  
M. Yusoff ◽  
M. N. Masri
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Arc Discharge ◽  
Synthesis Method ◽  
Chemical Vapor ◽  
Plasma Cvd ◽  
Microwave Plasma Cvd ◽  
Discharge Laser

Development of carbon nanotubes was done by several methods like arc discharge, laser ablation, silane solution, flame synthesis method but the standard or famous technique using chemical vapor deposition (CVD). CVD is one of the approaches to develop CNT, due to easy control of the reaction course and high purity of the obtained materials. Various type of CVD present like thermal CVD, plasma enhanced CVD, or microwave plasma CVD. These kinds of types give the different advantage and drawbacks to the production of CNT and its preparations.

Nitrogen and Bias Effect on Homoepitaxial Diamond Growth by Hot-Filament Chemical Vapor Deposition

2010 ◽  
Vol 443 ◽  
pp. 510-515 ◽  
Author(s):  
Hung Yin Tsai ◽  
Chih Cheng Chang ◽  
Chih Wei Wu
Keyword(s):  
Growth Rate ◽  
Chemical Vapor Deposition ◽  
Diamond Film ◽  
Vapor Deposition ◽  
Diamond Films ◽  
Chemical Vapor ◽  
High Growth ◽  
High Growth Rate ◽  
High Quality ◽  
Hot Filament

The development of homoepitaxial films for advanced device applications has been studied, but high growth rate and diamond film quality have not yet been explored. In the current study, high quality homoepitaxial diamond films were grown on type Ib (100) HPHT synthetic diamond substrate by hot-filament chemical vapor deposition. The reactant gases were mixed by CH4 and H2 with small amounts of N2 (500 to 3000 ppm). Besides, a bias system was used to assist diamond film deposition. The pyramidal crystals on diamond surface can be suppressed and high quality diamond film of FWHM (Full Width at Half Maximum) = 10.76 cm-1 with high growth rate of 8.78 ± 0.2 μm/ hr was obtained at the condition of adding 1000 ppm nitrogen. At the bias voltage of -150 V, the pyramidal crystals can also be suppressed and high quality diamond film of FWHM = 10.19 cm-1 was obtained. With nitrogen addition above 2000 ppm, diamond film was partly doped and some sp2 structures appeared. These homoepitaxial diamond films were characterized by optical microscopy and micro-Raman spectroscopy.

High efficiency deposition of diamond film by hot filament chemical vapor deposition

1996 ◽  
Vol 11 (12) ◽  
pp. 2957-2960 ◽  
Author(s):  
Yan Chen ◽  
Qijin Chen ◽  
Zhangda Lin
Keyword(s):  
Growth Rate ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Gas Flow ◽  
Film Growth ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Reaction Chamber ◽  
Deposition Area ◽  
Hot Filament

A new designed reaction chamber with new relative distribution of filament and substrates has been adopted in order to increase the deposition area of diamond films and thus increase the deposition efficiency in conventional hot filament chemical vapor deposition (HFCVD) systems. The relatively small reaction chamber was cuboid shaped (50 × 25 × 25 mm3) and composed of molybdenum wafers. It was established in the vacuum chamber. A tungsten filament was hung up vertically in the center of the small chamber and parallel to the gas flow path. At the four inner sides of the reaction chamber, four Si(100) substrates (30 × 10 × 0.5 mm3) were installed to grow diamond films. The deposition results indicate that uniform diamond films can be obtained on the four substrates, and the film growth rate is the same at both ends of the substrates. The diamond film growth rate was about 1−2 μm/h, which is similar to those of the conventional HFCVD method. Thus, the deposition area and efficiency can be increased four times in the case without the filament number, gas flow rate, and power consumption.

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