Film characterization and mechanistic studies of fluorosilane plasmas: From film chemistry to radical-surface reactions

The effects of plasma parameters, including rf power (P), substrate temperature, and feed gas concentrations were studied in inductively coupled rf plasmas. A variety of gas phase, gas-surface, and surface analysis techniques were used to provide a complete study of SiF4 and SiF₄/H ₂ plasma systems resulting in elucidation of gas and gas-surface interface reactions responsible for silicon etching and fluorinated silicon film deposition. From these data, three plasma types are defined. Type 1 plasmas result in silicon etching. Type 2 systems neither etch nor deposit, and plasmas resulting in net deposition are defined as Type 3. Gas phase and surface reactions to describe these three plasma types are proposed.