Evaporation rate and composition monitoring of electron beam physical vapor deposition processes

Lawrence Livermore National Laboratory (LLNL) is developing sensor and control technology to improve the quality and range of applicability of electron beam physical vapor deposition (PVD). The approach being developed uses tunable lasers to measure the density and composition of the vapor plume. This paper reviews the principles of operation of laser based sensors and discusses data from experiments in which titanium and niobium are co-vaporized. Laser data agreed well with deposited film compositions and spatial variations in deposited film cross-sections. Laser based vapor monitoring appears to have broad applicability and has the potential to extend the use of high rate electron beam PVD.