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

A new method of deposition of diamond films with the use of supersonic gas flows activated by a microwave discharge is implemented for the first time. The operation principle of the proposed gas-discharge system is similar to that of a microwave electrothermal thruster. A mixture of hydrocarbons and hydrogen is used as a plasma-forming gas. It is demonstrated that the proposed method allows the plasma-forming gas to be used at pressures far above the upper limit of the pressure range of modern microwave plasma systems for chemical vapor deposition of diamond films (approximately 40 000 Pa).