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 both 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. Rather, photodissociation and metastable atom-molecule reactions dominate in the downstream afterglow. To better understand electron-beam-created plasmas using a slotted ring cathode, the transmitted beam spatial intensity profiles have been quantified from initial generation at a slotted line-shaped cold cathode through acceleration in the cathode sheath and propagation in the ambient gas. To better understand the role of photodissociation in downstream plasma-assisted CVD, the VUV output spectrum and VUV generation efficiency from electron-beam-excited plasmas have been measured. The properties of films deposited via both direct electron-beam-generated plasma-assisted CVD and downstream afterglow CVD are reviewed and compared to conventional plasma assisted CVD films