Open AccessReal time sensor for monitoring oxygen in radio–frequency plasma applications
Author(s) -
Vladimir Milosavljević,
Ronan Faulkner,
M. B. Hopkins
Publication year - 2007
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.15.013913
Subject(s) - actinometer , plasma , argon , spectrometer , trace gas , optics , inductively coupled plasma , materials science , buffer gas , radio frequency , plasma diagnostics , physics , atomic physics , laser , computer science , telecommunications , quantum mechanics , meteorology
Real time closed loop control of plasma assisted semiconductor manufacturing processes has received significant attention in recent years. Therefore we have developed and tested a customized optical sensor based on buffer gas (argon) actinometry which has been used to determine relative densities of atomic and molecular oxygen in an Ar/O(2) radio-frequency ICP chamber. The operation and accuracy of our optical sensor compared favorably with a high resolution commercial spectrometer but at lower cost and exhibited improved actinometric performance over a low resolution commercial spectrometer. Furthermore, threshold tests have been performed on the validity of buffer gas based actinometry in Ar/O(2) ICP plasmas where Ar is no longer a trace gas through Xe actinometry. The plasma conditions for which this customized optical sensor can be used for closed loop control have been established.