Atomic oxygen characterisation in a RIE O2/Ar discharge using Laser-Induced Fluorescence and Mass Spectrometry

摘要

Reported on here are absolute atomic oxygen density variations with various plasma control parameters such as RF power and gas pressure using two-photon absorption laser induced fluorescence (TALIF) and mass spectrometry. These diagnostics provide a benchmark measurement to validate radical density estimation using OES (Actinometry) which in some cases prove be an unreliable measurement due to imprecise rate constants and misinterpretation of spectral emission lines. In IC manufacturing, process variation is largely related to the control of the oxygen radical density which can drift due to a change in wall condition or wafer loading affects. The results discussed in this work focus on identifying and monitoring such process variation in conjunction with real time control strategies with a view to improve the repeatability of industrial plasma processes.