NOVEL MICROWAVE PLASMA REACTOR FOR DIAMOND SYNTHESIS

Numerical simulations were performed to predict the performance of mic rowave plasma reactors with various reactor geometries. The simulation s include the calculation of the electric field distribution using the finite integration theory and the determination of the plasma density distribution based on a breakdown field algorithm. One reactor geomet ry with a cavity having the shape of a rotational ellipsoid turned out to be very promising. The electric field within this cavity exhibits two pronounced maxima at the two focal points of the ellipsoid. By cou pling microwave energy into one maximum via an antenna, large electric field strengths can be generated in the counter maximum. This effect has been used to excite intense discharges that are very stable, spati ally extended, homogeneous, and free from wall contact. These discharg es were employed for the chemical vapor deposition of large area diamo nd wafers. (C) 1998 American Institute of Physics. [S0003-6951(98)0181 0-5].