Gas temperature measurement in CF{sub 4}, SF{sub 6}, O{sub 2}, Cl{sub 2}, and HBr inductively coupled plasmas

Journal Article · Fri May 15 04:00:00 EDT 2009 · Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films

DOI:https://doi.org/10.1116/1.3106626· OSTI ID:22050985

Cunge, G; Ramos, R; Vempaire, D; Touzeau, M; Neijbauer, M; Sadeghi, N ^[1]

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1. Laboratoire des Technologies de la Microelectronique, CNRS, 17 rue des Martyrs (CEA-LETI), 38054 Grenoble Cedex 9 (France)

Neutral gas temperature (T{sub g}) is measured in an industrial high-density inductively coupled etch reactor operating in CF{sub 4}, SF{sub 6}, O{sub 2}, Cl{sub 2}, or HBr plasmas. Two laser diodes are used to deduce T{sub g} from the Doppler widths of 772.38 and 811.5 nm lines absorbed by Ar*({sup 3}P{sub 2}) metastable atoms, when a small amount of argon (5%) is added to the gas flow. With the 811.5 nm beam passing parallel to the wafer, T{sub g} near the wafer surface is obtained by laser absorption technique. With the 772.38 nm beam entering the top of the reactor perpendicular to the wafer surface, the volume averaged temperature is deduced by laser induced fluorescence technique. The volume averaged T{sub g} increases with radio frequency power and with pressure, although the temperature near the walls is only weakly dependent on gas pressure. The main effect of increasing the pressure is an enhancement of the temperature gradient between the discharge center and the wall boundary. Due to the thermal accommodation, the authors always observe a significant temperature jump between the surface and the gas in its vicinity. This gap is typically about 200 K. Gas temperatures for a wide range of pressure and rf powers are reported. These data will be useful to validate and improve numerical models of high-density reactive plasmas.

• OSTI ID: 22050985
• Journal Information: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films, Journal Name: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films Journal Issue: 3 Vol. 27; ISSN 1553-1813
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ARGON
CARBON TETRAFLUORIDE
CHLORINE
DOPPLER EFFECT
ELECTRON TEMPERATURE
ETCHING
FLUORESCENCE
GLOW DISCHARGES
HYDROBROMIC ACID
ION TEMPERATURE
LASERS
OXYGEN
PLASMA
PLASMA DENSITY
PLASMA PRESSURE
SULFUR FLUORIDES
TEMPERATURE GRADIENTS
TEMPERATURE MEASUREMENT
WALL EFFECTS