BCxNy films were characterized as a potential pore sealing layer for low κ dielectrics. The changes in chemical bonding were studied as a function of growth temperature to aid in understanding the variation in electrical performance of these films.
Thermal chemical vapor deposition of BCxNy using dimethylamine borane and ethylene
were deposited on porous methylsilsesquioxane substrates at 335 °C and 1 Torr. BCxNy
was able to seal the porous interface with a thickness of 3.9 nm for both blanket and
patterned substrates. BCxNy films deposited over a temperature range of 300-400 °C with
dimethylamine borane and either ethylene or ammonia coreactant gas were characterized.
Films deposited with ethylene became more concentrated in B at the expense of C with
increasing temperature. These films favored C-B intermixing over C-C and B-B bonding
at higher temperature. H was detected in the form of B-H and C-H bonds. Films
deposited with ammonia became concentrated in N at the expense of B, and favored B-N
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bonding at higher temperatures. H was found in the films as B-H, C-H, and N-H bonds.
The amount of H in the films decreased with increasing growth temperature for both
ethylene and ammonia coreacted films. The valence band offset of C-rich films increased
from 0.17 ± 0.22 eV to 0.32 ± 0.22 eV when deposited at 300°C and 400 °C. For the Nrich
films, the valence band offset shifted from 0.26 ± 0.28 at 300 °C to -0.15 ± 0.24 eV
at the same deposition conditions. High temperature annealing from 400-800 °C in
forming gas caused all BCxNy films to decrease in thickness up to 30%. At the same time,
the index of refraction increased, and likely, the dielectric constant. X-ray photoelectron
spectroscopy revealed little change in the constituent bonding, suggesting that volatile –H
containing species were removed during the annealing process. / text
| Identifer | oai:union.ndltd.org:UTEXAS/oai:repositories.lib.utexas.edu:2152/ETD-UT-2010-12-2144 |
| Date | 14 February 2011 |
| Creators | Ahearn, Wesley James |
| Source Sets | University of Texas |
| Language | English |
| Detected Language | English |
| Type | thesis |
| Format | application/pdf |
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