Surface loss rates of H and Cl radicals in an inductively coupled plasma etcher derived from time-resolved electron density and optical emission measurements

Journal Article · Mon Mar 15 00:00:00 EDT 2010 · Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films

DOI:https://doi.org/10.1116/1.3330766· OSTI ID:22051149

Curley, G A; Gatilova, L; Guilet, S; Bouchoule, S; Gogna, G S; Sirse, N; Karkari, S; Booth, J P ^[1]

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1. Laboratoire de Photonique et de Nanostructures (LPN)-CNRS, Route de Nozay, Marcoussis 91460 (France)

A study is undertaken of the loss kinetics of H and Cl atoms in an inductively coupled plasma (ICP) reactor used for the etching of III-V semiconductor materials. A time-resolved optical emission spectroscopy technique, also referred to as pulsed induced fluorescence (PIF), has been combined with time-resolved microwave hairpin probe measurements of the electron density in a pulsed Cl{sub 2}/H{sub 2}-based discharge for this purpose. The surface loss rate of H, k{sub w}{sup H}, was measured in H{sub 2} plasma and was found to lie in the 125-500 s{sup -1} range ({gamma}{sub H} surface recombination coefficient of {approx}0.006-0.023), depending on the reactor walls conditioning. The PIF technique was then evaluated for the derivation of k{sub w}{sup Cl}, and {gamma}{sub Cl} in Cl{sub 2}-based plasmas. In contrast to H{sub 2} plasma, significant variations in the electron density may occur over the millisecond time scale corresponding to Cl{sub 2} dissociation at the rising edge of the plasma pulse. By comparing the temporal evolution of the electron density and the Ar-line intensity curves with 10% of Ar added in the discharge, the authors show that a time-resolved actinometry procedure using Ar as an actinometer is valid at low to moderate ICP powers to estimate the Cl loss rate. They measured a Cl loss rate of {approx}125-200 s{sup -1} (0.03{<=}{gamma}{sub Cl}{<=}0.06) at 150 W ICP power for a reactor state close to etching conditions. The Cl surface loss rate was also estimated for high ICP power (800 W) following the same procedure, giving a value of {approx}130-150 s{sup -1} ({gamma}{sub Cl}{approx}0.04), which is close to that measured at 150 W ICP power.

• OSTI ID: 22051149
• Journal Information: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films, Vol. 28, Issue 2; Other Information: (c) 2010 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1553-1813
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CHLORINE
DISSOCIATION
ELECTRIC DISCHARGES
ELECTRON DENSITY
EMISSION SPECTROSCOPY
ETCHING
FLUORESCENCE
HYDROGEN
ICP MASS SPECTROSCOPY
MICROWAVE RADIATION
OXYGEN
RADICALS
RECOMBINATION
SEMICONDUCTOR MATERIALS
SPUTTERING
TIME RESOLUTION
WALL EFFECTS