Radiative and Electrical Properties of a Planar Magnetron Glow Discharge Device

A glow discharge with a planar cathode in a curved magnetic field is described. The device relies on gradient drift, curvature drift, and electrostatic reflection of electrons to obtain high cathodic sputtering rates at unusually low voltages and pressures. Gradient drift and curvature drift of electrons occur when the magnetic field is inhomogeneous or nonlinear, respectively. The device is characterized in the pressure range from 1.0 to 0.01 Torr. Line intensities from cathodically sputtered material are highest, and continuum background intensity lowest, at pressures less than 0.06 Torr. Design features and performance data are considered.