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T. Frischmuth, M. Schneider, Th. Grille, U. Schmid:
"FT-IR analysis of high temperature annealing effects in a-SiC:H thin films";
Talk: SPIE Microtechnologies 2017, Barcelnoa, Spanien; 05-08-2017 - 05-10-2017; in: "Proc. SPIE 10246, Smart Sensors, Actuators, and MEMS VIII", SPIE, (2017), ISSN: 1996-756x; Paper ID 102460R, 6 pages.

Hydrogenated amorphous SiC (a-SiC:H) is an attractive material for MEMS applications where high robustness or
operation in harsh environments is targeted. In previous publications, it was demonstrated, that the properties of a-SiC:H
thin films can be tailored over a wide range by changing the auxiliary table excitation power of a dual plasma source
deposition process using an inductively coupled plasma-enhanced chemical vapour deposition system. In this work, the
annealing behavior of dual plasma source deposited a-SiC:H thin films under argon atmosphere is investigated by using
Fourier transform infrared (FT-IR) spectroscopy for chemical analysis. All investigated layers show a decrease of
hydrogen containing bonds (X-Hx) and an increase of Si-C bonds with increasing annealing temperature in the FT-IR
spectrum. This behaviour is directly linked to the effusion of hydrogen from the thin films at elevated temperatures. In
addition, films deposited at higher auxiliary plasma power show more X-Hx and less Si-C bonds, indicating a higher
hydrogen amount in those films. All layers shrink with increasing annealing temperature due to the effusion of hydrogen
with a stronger shrink at higher PT values caused by the increased hydrogen amount. This shrink also leads to a
densification of the thin films.

Hydrogenated amorphous SiC (a-SiC:H) is an attractive material for MEMS applications where high robustness or
operation in harsh environments is targeted. In previous publications, it was demonstrated, that the properties of a-SiC:H
thin films can be tailored over a wide range by changing the auxiliary table excitation power of a dual plasma source
deposition process using an inductively coupled plasma-enhanced chemical vapour deposition system. In this work, the
annealing behavior of dual plasma source deposited a-SiC:H thin films under argon atmosphere is investigated by using
Fourier transform infrared (FT-IR) spectroscopy for chemical analysis. All investigated layers show a decrease of
hydrogen containing bonds (X-Hx) and an increase of Si-C bonds with increasing annealing temperature in the FT-IR
spectrum. This behaviour is directly linked to the effusion of hydrogen from the thin films at elevated temperatures. In
addition, films deposited at higher auxiliary plasma power show more X-Hx and less Si-C bonds, indicating a higher
hydrogen amount in those films. All layers shrink with increasing annealing temperature due to the effusion of hydrogen
with a stronger shrink at higher PT values caused by the increased hydrogen amount. This shrink also leads to a
densification of the thin films.

http://dx.doi.org/10.1117/12.2266844