Synthesis of Diamonds from the Microwave Plasma with the Use of Supersonic Gas Flows

Ребров, А. К.; Isupov, M. V.; Litvintsev, A. Yu.; Burov, V. F.

doi:10.1134/s0021894418050012

Cited by 13 publications

(8 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A common feature of this approach is the creation of a plasma cloud above the substrate, from which active fragments participating in the formation of diamond crystals diffuse to the surface. The MPCVD method was further developed in [4][5][6] for the deposition of diamond structures using a microwave discharge to activate gases. The use of jet supersonic plasma expansion opens up the possibility of activating the initial gas mixture in the discharge chamber in a wide range of specific mass fluxes to the substrate without the pressure in the deposition chamber affecting this process.…”

Section: Introductionmentioning

confidence: 99%

Effective cooling of substrates with low thermal conductivity under conditions of gas-jet MPCVD diamond synthesis

Emel’yanov

Plotnikov

Тимошенко

et al. 2021

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

The paper presents the results of an experimental study of heating molybdenum and silicon substrates under the conditions of gas-jet deposition of diamond structures using the precursor gases of a microwave discharge to activate. A cooled substrate holder using a metal melt to improve heat removal by reducing the thermal resistance between the substrate and the substrate holder has been developed. The use of the melt allowed lowering the temperature of the silicon substrate under the conditions of gas-jet deposition to a level that ensures the preservation of its structure. The developed substrate holders were used to carry out gas-jet synthesis of diamond structures on molybdenum and silicon substrates.

show abstract

Section: Introductionmentioning

confidence: 99%

Effective cooling of substrates with low thermal conductivity under conditions of gas-jet MPCVD diamond synthesis

Emel’yanov

Plotnikov

Тимошенко

et al. 2021

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

show abstract

“…One of the promising directions in the development of chemical vapor deposition (CVD) [1][2][3] is the use of a microwave discharge to activate the mixture. The possibility of focusing the plasma potentially allows controlling the position and intensity of the discharge by changing the geometry of the resonance chamber.…”

Section: Introductionmentioning

confidence: 99%

Numerical investigation of energy transfer efficiency from microwave radiation to plasma in a cylindrical resonant cavity

Hrebtov

Bobrov

2021

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

The paper presents a simplified numerical model of the hydrogen plasma generation process in a microwave resonant cavity. The model assumes electroneutrality and the prescribed electron temperature of the plasma, thus significantly reducing the computational cost. This allows for the parametric study in a wide range of operating pressures end electric field magnitudes (at a frequency of 2.45GHz). The prescribed model allows finding the effective range of operating pressures for the plasma generation. At low pressures, the collision rate is too low to effectively absorb all the emitted energy while at high pressures the electron conductivity drops which also reduces the absorption efficiency.

show abstract

“…From that cloud active molecular fragments diffuse to the surface of the substrate [1]. However, a new deposition method has recently emerged, in which active fragments formed in a plasma cloud flow from a resonant chamber into a vacuum deposition chamber in form of a supersonic jet [2]. This method allows the use of plasma at very high pressures.…”

mentioning

confidence: 99%

“…In this paper, we present the results of optimization of the geometrical parameters of the resonant chamber achieved by means of numerical simulation. A baseline chamber design was chosen to mimic an experimental setup from [2].…”

mentioning

confidence: 99%

“…First experimental results on the diamond deposition with using analyzed external nozzle configurations have been positive and encouraging. These tests with setup from [2] showed that such modification (either cone or hemisphere) increased a working temperature inside the chamber significantly and made the discharge more stable even for higher pressures (up to 300 torr. and more).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Numerical simulation of the activation process of supersonic gas flows by a microwave discharge.

Bobrov

Hrebtov

Ребров

2019

Proceedings 17th International Conference on Microwave and High Frequency Heating

View full text Add to dashboard Cite

Supersonic gas flows activated by microwave discharge are commonly used to obtain thrust for spacecraft. When using a mixture of hydrocarbons and hydrogen as a working gas, the proposed method generates high-speed plasma streams with a high concentration of radicals, allowing it to be used for efficient deposition of diamond films . To optimize diamond synthesis processes, it is necessary to study the effect of various system parameters (geometrical dimensions, radiation power, pressure and others). This abstract presents a numerical simulation of the formation of high-speed gas flow activated by a microwave discharge. The conjugate problem of hydrodynamics and plasma dynamics was solved in the continuum approximation, taking into account impact ionization and thermal dissociation, due to microwave heating of the gas. The simulations were carried out in an axisymmetric formulation. The region of plasma flow formation was a cylindrical chamber (radius 5 cm, height 7 cm). At this stage, hydrogen was chosen as the working gas. The flow outlet is a hole at the center of the lower boundary with fixed pressure of 2 torr. The gas entered the domain at a constant flow rate of 20 l/min through the openings in side wall along its normal. Such flow rate sustained the mean pressure in the chamber at the level 200 torr. Microwave radiation was injected by a coaxial port located above the plasma chamber. The geometrical dimensions of the resonant chamber were selected in order to form the maximum of the electric field intensity over the gas outflow region (total deposited power 1000W). The distributions of velocity, temperature, and concentrations of all components of the hydrogen plasma were estimated. Optimal characteristics of the system were found to reach a high mole fraction of atomic hydrogen, necessary diamond deposition.

show abstract

Synthesis of Diamonds from the Microwave Plasma with the Use of Supersonic Gas Flows

Cited by 13 publications

References 10 publications

Effective cooling of substrates with low thermal conductivity under conditions of gas-jet MPCVD diamond synthesis

Effective cooling of substrates with low thermal conductivity under conditions of gas-jet MPCVD diamond synthesis

Numerical investigation of energy transfer efficiency from microwave radiation to plasma in a cylindrical resonant cavity

Numerical simulation of the activation process of supersonic gas flows by a microwave discharge.

Contact Info

Product

Resources

About