Spectroscopy Diagnosis Of Argon And Carbon Tetrafluoride Microwave Plasmas

Low pressure radio frequency Ar/CF4 plasma is often used to study plasma etching and that has got very comprehensive data analysis. The research on microwave discharge is rare, especially diagnosing electron temperature and the density of some special particles by spectroscopy. In order to understand the discharge characteristics and complex physical and chemical reaction process in Ar/CF4 microwave plasma, the plasma was diagnosed by emission spectroscopy and tunable diode laser absorption spectroscopy. The variation trend about electron temperature and F atom concentration was measured by emission spectroscopy with the microwave power, pressure and gas proportion changes; the variation trend about the density of Ar metastable state 1S5, 1S3 and gas temperature was measured by tunable diode laser absorption spectroscopy with the microwave power and pressure. This paper has come to the following conclusions:(1) The electron temperature was calculated and compared by Fermi-Dirac distribution model and Corona model. Electron temperature increase slowly with power increase, the value is about 0.8 eV by Fermi-Dirac distribution model and about 0.7 eV by Corona model; electron temperature decrease quickly with pressure and Ar proportion increase, and the value of electron temperature calculated by this two model become more closer.(2) Using Ar as tracer gas, the variation trend about F atom concentration was measured. The density of F atom increase with power and pressure increase.(3) According to Lambert-Beer, the density of Ar 1S5, 1S3 was measured. The density of Ar 1s5 is about 1016 m-3, which ten times more 1s3, and they decrease with power and pressure increase.(4) According to the doppler broadening of 1S3 absorption line, the gas temperature was measured. The gas temperature is from 1600 K to 2600 K, and increase with power and pressure increase.