AVS 53rd International Symposium
    Plasma Science and Technology Thursday Sessions
       Session PS-ThP

Paper PS-ThP5
Electron Density and Electron Temperature of Narrow-Gap RF Plasma Polymerization System Measured by Highly-Sensitive Double Surface Wave Probe Technique

Thursday, November 16, 2006, 5:30 pm, Room 3rd Floor Lobby

Session: High Pressure Discharges and Novel Diagnostics & Sources Poster Session
Presenter: K. Kinoshita, MIRAI-ASET, Japan
Authors: K. Kinoshita, MIRAI-ASET, Japan
K. Nakamura, Chubu University, Japan
O. Hirano, Chubu University, Japan
Y. Hyodo, MIRAI-ASET, Japan
O. Kiso, MIRAI-ASRC, AIST, Japan
J. Kawahara, MIRAI-ASET, Japan
Y. Hayashi, NEC, Japan
S. Saito, Selete, Japan
H. Sugai, Nagoya University, Japan
T. Kikkawa, Hiroshima University, Japan
Correspondent: Click to Email
A plasma copolymerization technique has been developed to achieve scalability of low-k materials for two or three technology nodes of ULSIs. In-situ QMS analysis showed that multistep dissociation of the precursor monomers progressed in the plasma.@footnote 1@ Low-k property of the deposited film was lost by over dissociation. Thus, the following three points are indispensable; (a)reduction of electron density (Ne), (b)lowering electron temperature (Te), and (c)reduction of gas residence time. In this study, electron temperature was measured for actual deposition plasma by double surface wave probe technique. This technique enables to measure Ne and Te by the difference of surface wave resonance frequencies.@footnote 2@ An RF plasma CVD system for 300 mm wafer was used. A cyclosiloxane monomer with six-member ring and organic functional groups was used as a precursor monomer with helium carrier gas.@footnote 3@ While increasing precursor flow rate from 0 sccm to 10 sccm (1.7 %), Ne decreased rapidly from 5.2E10 cm@super -3@ to 1.4E10 cm@super -3@. On the other hand, Te decreased gradually from 2 eV to 0.5 eV at the flow rate from 0 sccm to 40 sccm (6.7 %), and kept constant over this flow rate range up to 100 sccm. These results indicate that Te of the plasma polymerization process was low enough even in the helium discharge. Radial distributions of Ne and Te were affected by the gas pressure change. Uniform discharge was obtained at the gas pressure of 400 Pa, and the source power of 200 W (Ne=1.5E10 cm@super -3@). To optimize plasma polymerization process, some hardware knob for uniformity control would be effective to achieve better process margins. This work was supported by NEDO. @FootnoteText@ @footnote 1@ K. Kinoshita, et al., Proc. Dry Process Symp. 2003, Tokyo, 3-1, 61 (2003).@footnote 2@ O. Hirano, et al., Abst. Spring Meeting Jpn. Soc. Appl. Phys., 25a-W-7, (2006)@footnote 3@ Y. Hayashi, et al., Proc. 2004 IEEE Int. Interconnect Technol. Conf., 12.3, (2004).