AVS 46th International Symposium
    Plasma Science and Technology Division Thursday Sessions
       Session PS-ThM

Paper PS-ThM7
Inorganic Plasma Low-k Materials - Aurora 2.7 -

Thursday, October 28, 1999, 10:20 am, Room 609

Session: Plasma-Surface Interactions II
Presenter: N. Matsuki, ASM Japan K.K.
Authors: N. Matsuki, ASM Japan K.K.
Y. Morisada, ASM Japan K.K.
Y. Naito, ASM Japan K.K.
A. Matsunoshita, ASM Japan K.K.
Correspondent: Click to Email
Methyl-SiO and Phenyl Methyl-SiO interlayer dielectric (ILD) films with dielectric constants in the 2.6 to 3.0 range were successfully obtained by PE-CVD method. Precursors used to deposit these low-k films were Dimethyldimethoxysilane Si (CH@sub 3@)@sub 2@(OCH@sub 3@)@sub 2@ and Phenylmethyldimethoxysilane Si (C@sub 6@H@sub 5@) (CH@sub 3@)(OCH@sub 3@)@sub 2@, respectively. Reaction gases consisting one of these precursors and some additive gas such as He or H@sub 2@ were introduced into the Eagle-10 reaction chamber with conventional parallel plate electrodes. These films were deposited in 400 @super o@C plasma process without an anneal step. Residence time of gas molecules in the reaction space was prolonged to enhance disintegration and polymerization in the gas phase. FT-IR data suggest that these plasma low-k films have stable Si-O network structure incorporating hydrocarbons (-CH3 or -C6H5), thus avoiding Si-OH formation. TDS and TGA data show these films have high thermal stability up to 500 @super o@C. The dielectric constant did not increase after a pressure cooker test at 120 @super o@C and RH 100% for an hour. The leakage current was found to be 10@super -9@ (A/cm@super 2@) at 2 MV/cm. The surface roughness was less than 5 nm (1µm film, P-V). The CMP rate was less than 5 nm/min using Cu CMP slurry at a Cu polishing speed of 300 nm/min. Thus, it appears that these stable low-k films have ideal properties for Cu damascene metallization insulation layers.