Experimental study of spatial nonuniformities in 100 MHz capacitively coupled plasma using optical probe

Journal Article · Thu May 15 04:00:00 EDT 2008 · Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films

DOI:https://doi.org/10.1116/1.2899413· OSTI ID:21123906

Volynets, V N; Ushakov, A G; Sung, D; Tolmachev, Y N; Pashkovsky, V G; Lee, J B; Kwon, T Y; Jeong, K S ^[1]

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1. Mechatronics and Manufacturing Technology Center, Samsung Electronics Co. Ltd., 416 Maetan-3 dong, Yeongtong-Gu, Suwon, Gyeonggi-Do 443-742 (Korea, Republic of)

Plasma spatial nonuniformities in the 100 MHz rf driven capacitively coupled reactor used for reactive ion etching of 300 mm substrates were experimentally studied using a linear scanning optical emission spectroscopy probe. Radial profiles of plasma emission intensity were measured both in argon and fluorocarbon-containing gas mixtures in the pressure interval of 10-80 mTorr and the rf power range of 500-1250 W. It was demonstrated that the plasma emission profiles strongly depend on the working gas composition and pressure. The profiles have a bell-like shape at pressures about 10 mTorr for all gases. As the pressure increases, the profile shape becomes more complex with the central and peripheral peaks, and the amplitudes of the peaks strongly depend on the working gas composition. It is suggested that the emission profiles show plasma spatial nonuniformities that can influence the etching rate profiles obtained with such systems. According to the existing theoretical models, the most probable reasons for these plasma nonuniformities are charged particle radial diffusion at low pressures (about 10 mTorr), as well as the standing wave and skin and edge effects at higher pressures. Using the experimental emission profiles, the working conditions have been found that allow one to achieve the most uniform plasma for discharges in argon and fluorocarbon-containing gas mixtures.

• OSTI ID: 21123906
• Journal Information: Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films, Journal Name: Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films Journal Issue: 3 Vol. 26; ISSN 0734-2101; ISSN JVTAD6
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ARGON
BOUNDARY LAYERS
EMISSION
EMISSION SPECTROSCOPY
ETCHING
HIGH-FREQUENCY DISCHARGES
IONS
MHZ RANGE 01-100
MIXTURES
PEAKS
PLASMA
PRESSURE RANGE MEGA PA 10-100
PROBES
SKIN EFFECT