Energetic neutral fluxes towards surfaces in a magnetically enhanced reactive ion etch-like reactor

Abstract

In very large scale integrated microelectronics fabrication magnetically enhanced reactive ion etch (MERIE) reactors are established for many dry etch processes of conducting or dielectric materials. Angularly and energetically resolved distributions of the surfaces incident particles (ions and neutrals) as well as the fluxes of ions and neutrals play an essential role for feature scale profile evolution. The focus of this work is set on the calculation of the neutral to ion fluxes ratio. Therefore the MERIE reactor’s boundary sheath is simulated by the technology-oriented computer aided design simulation tool hybrid plasma sheath model (HPSM). HPSM consists of a self-consistent coupling of a fluid dynamical part to a Monte Carlo part. The sheath and presheath regions are described in one unified model. Energetic neutrals impinging the surface can be monitored in addition to the positive ion species. Simulations with parameters in the range of about 100 mTorr, rf voltages of a few 100 V, magnetic fields of about 90 G, and plasma powers of about 1000 W are presented. The simulations show that the flux of the energetic neutrals compared to the flux of the ions is not neglectable and that the neutral flux makes an important contribution to the energy budget of the surface impinging particles.