Properties of plasma in shielded dual-spiral antenna ICP system

Abstract

Summary form only given, as follows. The plasma properties have been investigated in an experimental system utilizing an external dual-spiral antenna coupled to the plasma through a dielectric window and a structured electrostatic shield. The Langmuir probe (LP), microwave interferometer (MWI) and self-excited electron resonance spectroscopy (SEERS) technique were used to study properties of produced plasma. The ICP RF power used in this study was in range up to 5 kW (13.56 MHz) and argon pressures from 2 to 15 Pa. At these conditions high density plasma (above 1012 cm/sup -3/ and electron temperature of 2 eV) has been produced due to strong inductive coupling of antenna to plasma. Spatial properties of plasma parameters (ne(i), Te, Vp and Vf) vs. ICP power and argon pressure and using electrostatic shield at different electrical condition were measured and compared to RF field simulations. The hysteresis of L to H-mode conversion was observed. Potential application of dual-spiral antenna for ionized PVD and feasibility of monitoring an ionized PVD process by SEERS technique were investigated. The extended application of SEERS technique was proven for ICP including Cu in discharge chemistry. The effect and efficiency of an inductive coupling using various electrostatic shield internal structures were simulated and verified by experiment. The results of computer simulation of antenna parameters were in good correlation with experimental results and used as predictive tool for new antenna designs.