Microwave interferometer applied to pulsed oxygen plasma

Summary form only given. The propagation of microwaves through pulsed RF oxygen plasma with no external magnetic field has been studied both analytically and experimentally. An analytical model describing the effect of collisions on reflection, transmission, and absorption coefficients of the plasma has been applied to this pulsed RF plasma source. A 290-kHz, 330-J pulsed RF power source has been used to create plasma from oxygen gas that was puffed into the vacuum chamber (base pressure 5×10^-5 torr). The pulsed RF power was coupled to the plasma by a one-turn coil with a width of 10 cm wrapped around the glass vacuum chamber at one end. An X-band (9.2-GHz) microwave interferometer has been employed to investigate the electron number density of the pulsed RF oxygen plasma. The average electron density (≃10¹² cm^-3) of the oxygen plasma has been obtained from the detected signal of the microwave interferometer by counting the number of fringes. The microwave interferometer has been calibrated with Langmuir probe data, so that the microwave-, interferometer can then be used in monomer plasmas for deposition of plasma polymerized thin films