Noninvasive method to measure the electron temperature in radio frequency capacitively coupled plasmas

Abstract

The electron temperature Te is a key plasma parameter in both industrial plasma processes and fundamental laboratory research. A noninvasive method to measure Te in current and next-generation semiconductor plasma processes is urgently required for fine-tuning the processing result and virtual metrology based on the plasma monitoring. In this Letter, we propose a noninvasive method for obtaining Te in radio frequency capacitively coupled plasma (CCP) by measuring the floating potential and substrate potential. The Te obtained using this simple method was compared with the results measured by a floating Langmuir probe in both pure Ar and Ar/He mixture CCPs, and they showed good agreement.