AVS 52nd International Symposium
    Plasma Science and Technology Wednesday Sessions
       Session PS+TF-WeM

Invited Paper PS+TF-WeM1
Developments of Plasma Copolymerization Technique for Deposition of low-k Films

Wednesday, November 2, 2005, 8:20 am, Room 302

Session: Plasma Enhanced CVD and ALD
Presenter: K. Kinoshita, Mirai-Aset, Japan
Authors: K. Kinoshita, Mirai-Aset, Japan
A. Nakano, Mirai-Aset, Japan
N. Kunimi, Mirai-Aset, Japan
M. Shimoyama, Mirai-Aset, Japan
J. Kawahara, Mirai-Aset, Japan
O. Kiso, Mirai-Asrc, Aist, Japan
Y. Seino, Mirai-Asrc, Aist, Japan
Y. Takasu, Mirai-Asrc, Aist, Japan
M. Komatsu, Sumitomo Chem., Japan
K. Nakamura, Chubu University, Japan
T. Kikkawa, Hiroshima Univ., Japan
Correspondent: Click to Email
We have proposed the strategic concept of scalable low-k materials for ULSIs which can be used over two or three technology nodes.@footnote 1@ The major challenge to realize this concept is controlling the dielectric constant and mechanical strength. A plasma copolymerization technique has been developed for this purpose.@footnote 2@ Basic film properties will be determined by the matrix monomer, and modified by copolymerization with modification monomers. A narrow-gap CCP was employed to generate uniform discharge over the 300 mm wafer. A divinylsiloxane-bis-benzocyclobutene (DVS-BCB) was chosen as a starting matrix monomer. The dielectric constant of the polymerized DVS-BCB film was 2.78. Electron density of this polymerization plasma was about 1.5E10 cm@super -3@ as measured by surface wave probe technique.@footnote 3@ Modification monomers were chosen from the view points of the reactivity, the estimated dielectric constant of the monomers, and the vapor pressure. To increase film modulus, phenyl compounds with unsaturated functional groups were introduced. The copolymerization ratio corresponded to the film modulus.@footnote 4@ To reduce dielectric constant, aliphatic compound was introduced. However, copolymerization with DVS-BCB at 400 °C could not reduce the dielectric constant due to decomposition of aliphatic components. A process of low temperature deposition followed by annealing was examined with 2-dimethylvinylsiloxane-tricyclodecane (2DMVS-TCD). A dielectric constant of 2.48 was obtained by deposition at 300 °C followed by annealing at 400 °C. This work was supported by NEDO. @FootnoteText@ @footnote 1@ T. Kikkawa, Ext. Abst. ADMETA 2003: Assian session, Tokyo, 1-2, (2003) 4,@footnote 2@ J. Kawahara, et al., Technical Dig. IEDM 2003, 6-2, (2003) 143,@footnote 3@ K. Nakamura, et al., Proc. Int. Symp. Dry Process 2004, Tokyo, P-29, (2004) 169,@footnote 4@ N. Kunimi, et al., Proc. IITC2004, San Francisco, 8.5, (2004) 134.