Dry-etching properties of TiN for metal/high-k gate stack using BCl{sub 3}-based inductively coupled plasma

Journal Article · Sun Nov 15 04:00:00 EST 2009 · Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films

DOI:https://doi.org/10.1116/1.3244567· OSTI ID:22053545

Kim, Dong-Pyo; Xue, Yang; Woo, Jong-Chang; Um, Doo-Seung; Kim, Chang-Il ^[1]

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1. School of Electrical and Electronics Engineering, Chung-Ang University, 221 Heuksok-Dong, Dongjak-Gu, Seoul 156-756 (Korea, Republic of)

The etch rate of TiN film and the selectivities of TiN/SiO{sub 2} and TiN/HfO{sub 2} were systematically investigated in Cl{sub 2}/BCl{sub 3}/Ar plasmas as functions of Cl{sub 2} flow rate, radio-frequency (rf) power, and direct-current (dc) bias voltage under different substrate temperatures of 10 and 80 degree sign C. The etch rate of TiN films increased with increasing Cl{sub 2} flow rate, rf power, and dc-bias voltage at a fixed substrate temperature. In addition, the etch rate of TiN films at 80 degree sign C were higher than that at 10 degree sign C when other plasma parameters were fixed. However, the selectivities of TiN/SiO{sub 2} and TiN/HfO{sub 2} showed different tendencies compared with etch-rate behavior as a function of rf power and dc bias voltage. The relative-volume densities of Ar (750.0 nm), Cl (725.2 nm), and Cl{sup +} (386.6 nm) were monitored with an optical-emission spectroscopy. When rf power increased, the relative-volume densities of all studied particles were increased. X-ray photoelectron spectroscopy was carried out to detect nonvolatile etch by-products from the surface, and nonvolatile peaks (TiCl{sub x} bonds) in Ti 2p and Cl 2p were observed due to their high melting points. Based on the experimental results, we can conclude that the TiN etch is dependent on the substrate temperature when other plasma parameters are fixed. This can be explained by the enhanced chemical pathway with the assistance of ion bombardment.

• OSTI ID: 22053545
• 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: 6 Vol. 27; ISSN 1553-1813
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BORON CHLORIDES
CHLORINE
EMISSION SPECTROSCOPY
ETCHING
FLOW RATE
HAFNIUM OXIDES
LUMINESCENCE
MELTING POINTS
PLASMA
PROCESSING
RADIOWAVE RADIATION
SILICON OXIDES
SUBSTRATES
SURFACES
THIN FILMS
TITANIUM NITRIDES
X-RAY PHOTOELECTRON SPECTROSCOPY