DETERMINATION OF THE EMISSION CHARACTERISTICS OF EVAPORATION SOURCES AND OF THE THICKNESS AND COMPOSITION OF MIXED LAYERS

Methods are developed for determining the emission characteristics of enclosed evaporation sources with small apertures and for calculating the composition and thickness of mixed layers by controlling the conde nsation rates with quartz crystal monitors. For describing the emissio n characteristics of the sources the cos(n) law is used and a method f or determining n is presented. A procedure for calculating the composi tion and thickness of mixed layers at each point of stationary substra tes by measuring the condensation rates is described and the calculate d characteristics of the layers are experimentally confirmed by means of analytical, electron dispersive spectroscopy and profilometrical an alyses. The procedure is quits simple and does not require knowing the temperature dependence of the vapor pressure of the evaporated substa nces. It can be used for characterizing all layers obtained by evapora tion from one or more sources as well as for selecting the experimenta l conditions for obtaining layers of desired composition and thickness . (C) 1998 American Vacuum Society.