Patent ID: 7719681
Filing Date: 2010-05-18
Classification: C23C,G01J

Abstract:
1. Apparatus for monitoring vapor flux density of a species in a vacuum chamber by electron-impact emission spectroscopy in the presence of background gas species, comprising in combination: a first chamber disposed within said vacuum chamber having opposing apertures through which said vapor flux and background gas species can enter and exit said first chamber, and an aperture through which light can emerge from said first chamber; a first source of electrons disposed within said first chamber, wherein the electrons intersect said vapor flux, and wherein the electrons have a first chosen energy effective for exciting said species in said vapor flux such that light is emitted therefrom; a first power source for providing electrical power to said first source of electrons; a second chamber disposed within said vacuum chamber having an aperture through which said background gas species can enter said second chamber, and a pair of opposing apertures through which light emerging from the aperture of said first chamber enters said second chamber, and light from said first chamber and light from said second chamber exits said second chamber; a second source of electrons disposed within said second chamber, wherein the electrons intersect said background gas species, and wherein the electrons have a second chosen energy effective for exciting said background gas species such that light is emitted therefrom; a second power source for providing electrical energy to said second source of electrons; a wavelength selection apparatus for receiving light exiting said second chamber and for selecting a chosen wavelength range therefrom; and a photodetector for detecting light having a chosen wavelength range emerging from said wavelength selection apparatus, whereby light from said second chamber and light from said first chamber are processed such that said vapor flux density of said species is monitored.