Operation characteristics of an ICP plasma source

Summary form only given, as follows. The operation characteristics of an inductively-coupled plasma source have been measured by several different measurement techniques: Langmuir probe, 36 GHz heterodyne interferometer, optical emission spectroscopy and plasma impedance probe. The Ar plasma is generated by exciting a planar inductive coil with 13.56 MHz RF power which is coupled into the 400 mm diameter plasma chamber through a quartz window. Measurements have been made for two different size of antenna: 150 mm and 270 mm with window sizes 200 mm and 320 mm, respectively. The tip of the Langmuir probe is isolated from the bias and measurement electronics by an inductor to force the probe tip to follow the AC plasma floating potential. The 36 GHz heterodyne interferometer employs two free running Gunn oscillators and the phase change was measured by a 70 MHz quadrature mixer. The measurement results have been used to calibrate the Langmuir probe. The RF power absorbed by the plasma was measured by the plasma impedance probe placed between the antenna and matching network. Spatial variations of optical emission from the plasma for different operation conditions have also been measured by a monochrometer/CCD system with an optical fiber head.