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In this thesis, two major topics are studied:The first topic is
the reduction of RC delay time with combining low dielectric
constant materials such as fluorine-doped SiO2 (SiOF) and metal
chemical vapor deposition (tungsten and titanium/titanium
nitride). Silicon dioxide doped with fluorine (SiOF) may be used
as an intermetal dielectric in multilevel metallizations due to
its lower dielectric constant as compared to SiO2. But SiOF
absorbs moisture easily which results in an increase of the
dielectric constant and the via resistance. NH3 plasma post-
treatment can improve the moisture resistance of SiOF film.For
the aluminum substrate, pre-clean of aluminum via is critical to
the selective CVD-W process. Various pre-clean solutions are
tried to clean the aluminum surface. (NH2OH)2H2SO4+surfactant
is found to be effective in removing the native metal oxide (Al2
O3) prior to tungsten depesition.Before CVD Ti/TiN deposition,
various pretreatments are also used to remove Al2O3. We have
found that dry-etching has the best capability to remove Al2O3.
The second topic is the characterization of CVD-TiN film.
Conformal TiN films have been deposited by low pressure chemical
vapor deposition (LPCVD) in a rotating disk reactor, using TiCl4
and NH3 with N2 as dilute. TiN plugs with 500* contact size
have been firstly demonstrated. No void formation is observed
in the TiN plug. This result indicates that the LPCVD-TiN has
high ability for filling very fine contact holes. In addition,
deposition rates as a function of TiCl4 flow rates are measured.
Surfac
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