A review of microelectronic film deposition using direct and remote electron-beam-generated plasmas

Soft-vacuum-generated electron beams employed to create a large-area plasma for assisting chemical vapor deposition (CVD) of thin films are reviewed. The electron-beam plasma is used directly, where electron-impact dissociation of feedstock gases plays a dominant role, and indirectly in a downstream afterglow, where electron-impact dissociation of feedstock reactants plays no role. Photodissociation and metastable atom-molecule reactions dominate in the downstream afterglow. The transmitted beam spatial-intensity profiles are quantified from initial generation at a slotted line-shaped cold cathode through acceleration in the cathode sheath and propagation in the ambient gas. The vacuum ultraviolet (VUV) output spectrum and VUV generation efficiency from electron-beam-excited plasmas are measured. The properties of films deposited by direct electron-beam-generated plasma-assisted CVD and downstream afterglow CVD are reviewed and compared to conventional plasma-assisted CVD films