Characteristics of
Low-k Film Deposited by Plasma-Enhanced CVD Using a Liquid BCB Source
Suehiro Sugitani,
Hideaki Matsuzaki, and Takatomo Enoki
NTT Photonics
Laboratories, NTT Corporation
3-1, Morinosato
Wakamiya, Atsugi-shi, Kanagawa, 243-0198
E-mail:
sugitani@aecl.ntt.co.jp, Tel: +81-46-240-2312
Keywords: BCB, CVD, interlayer film, low dielectric
constant, interconnect
Abstract
Characteristics of organic
film deposited by plasma-enhanced CVD at low temperature below 250 °C using a
liquid source of BCB were investigated and compared with standard spin-coated
BCB. Uniform thin organic film was successfully deposited on 3-inch wafer with
thickness uniformity of 3%. Dielectric constant, breakdown voltage, and
moisture absorption of the film deposited by CVD are similar to spin-coated
BCB. It was found from FT-IR measurement, however, that the film deposited by
CVD has fewer Si atoms than spin-coated BCB and therefore it can be etched by
RIE using only O2 gas. The step-coverage of the film deposited by CVD is
conformal and considered advantageous for ultra-fine structures.