Broad fast neutral molecule beam sources for industrial-scale beam-assisted deposition

A new beam-assisted deposition technique is presented featuring fast neutral molecule beams being used instead of conventional ion beams. As compared with ions the neutral beams ensure better treatment stability, reliability, eliminate damage.,, of conductive films with unipolar arcs and substantially reduce the number of beam-induced defects in semiconductors and dielectrics. Fast molecules are being produced as a result of the primary ion beam interaction with slow gas molecules in a charge transfer collision chamber. Acceleration-deceleration of primary ions in two positive space charge layers separated from each other with one accelerating grid allows the beam current density up to 10 mA/cm(2) at any energy of accelerated particles beginning from 10 eV up to several keV. Due to generation of the ion emitter using a cold cathode glow discharge with electrostatic electron confinement, beams of any reactive gas molecules are available. By changing the shape of the accelerating grid and of the electrostatic trap, any beam configurations are available: converging: diverging: or highly coherent beams. Three pilot series of fast molecule sources are developed. Beam cross-section up to 10(4) cm(2) and current up to 10 A lead to industrial-scale beam-assisted deposition at 3 X 10(-4)-6 X 10(-3) mbar. Negative biasing of a target immersed in a plasma emitter of the beam source allows utilization of secondary electron emission for energy-effective heating of massive substrates and utilization of the target sputtering for metal vapor production. Both processes are inherently unavoidable but still rarely used by-processes of plasma immersion ion implantation. (C) 2002 Elsevier Science B.V. All rights reserved.