Development of a probe-type optical absorption spectroscopic system for spatially resolved CF2 density measurement in inductively coupled C4F8/Ar plasmas

Abstract

A spatially resolvable optical probe is developed for the measurement of absolute CF2 radical density in inductively coupled plasmas using the broadband ultraviolet absorption spectroscopic method. The probe-type system is implemented inside a low-pressure inductively coupled plasma chamber and is built using a series of optical fibers, feedthroughs, collimators, and an ultraviolet light emitting diode. Using the CF2 A(0, v2′, 0) ← X(0, 0, 0) absorption spectra, the spatial profile of CF2 density in the remote region of an inductively coupled C4F8/Ar plasma is investigated. The CF2 density is found to decrease from 4.06 × 1013 cm−3, around the chamber center, to 2.66 × 1013 cm−3, near the chamber wall. The spatial profile of the measured CF2 density, layer thickness, and composition of deposited films are compared. Plasma properties such as electron temperature and ion density are also discussed.

Importance of higher‐level excited species in argon remote plasma sources: Numerical modeling with consideration of detailed chemical reaction pathways

“…These studies have mainly been of an experimental nature in a pressure range from a few to tens of mTorr. [4][5][6][7][8][9][10][11][12][13] However, only a few experiments have been carried out in the Torr regime. [14][15][16][17] Although the pressure in several remote inductively coupled plasma (ICP) chambers is reported as typically being in the range of 0.01−1 Torr, the gas pressure in the RPS chamber is generally higher than expected because of the structure of RPS systems.…”