Development of a distributed ferromagnetic enhanced inductively coupled plasma source for plasma processing

Abstract

A low frequency (~100 kHz) distributed ferromagnetic enhanced inductively coupled plasma (FMICP) source with a separate supply of argon and chlorine into the main discharge chamber is proposed in order to obtain a large volume of dense (1010−1012 cm-3) uniform plasma at low pressures (1−100 mTorr). Argon is activated by FMICP sources in U-shaped tubes and diffuses into the main chamber, mixing with chlorine. The Ar/Cl2 mixture is also activated in the main discharge chamber by vortex alternating electric fields circulating in U-tubes and in the chamber. A separate supply of Ar into the side FMICP sources and Cl2 directly into the main chamber can significantly enhance the power transfer efficiency into the main discharge chamber to be used for plasma etching of 450 mm wafers.