Kinetic-Energy-Enhanced Neutral Etching

A review is presented of the emerging field of neutral-species kinetic-energy-enhanced etching of silicon. As the gate oxide thickness of metal oxide semiconductor field-effect transistors (MOSFET) is decreased to dimensions of 50 Å or less, the potentially damaging effects of high-kinetic-energy ions in plasma processing become important. New methods are required to remove material in a more refined, selective manner. In this review, the motivations for studies of neutral-species enhanced-kinetic-energy etching are described. Currently available sources of neutral reactive species with enhanced kinetic energies of 1-10 eV are discussed, and published experimental and theoretical investigations of enhanced-kinetic-energy neutral etching are reviewed. Problems associated with neutral species etching are also considered, and some possible future developments in the field are summarized.