Diagnostics of chlorine inductively coupled plasmas. Measurement of electron temperatures and electron energy distribution functions

Abstract

The goal of the study that begins with this paper is the creation of a base set of parameters (densities and temperatures or energy distributions of all charged and neutral species) in a chlorine transformer-coupled plasma, measured with the same commercial plasma source over an extensive range of pressure and power. Electron temperatures Te and electron energy distribution functions (EEDFs) are reported as a function of pressure (1–20 mTorr) and power (10–1000 W) during slow etching of SiO2-covered Si wafers. Te values are obtained both by trace rare gases optical emission spectroscopy and Langmuir probe methods. EEDFs are obtained with the Langmuir probe. A zero-dimensional (global) model with revised rate coefficients is used to compute Te from both minimum (pressure, total plasma density, gas temperature, and wall recombination coefficient) and maximum (all experimentally measured parameters necessary to calculate Te) sets of input parameters.