ICMCTF 2012! - CD-Lab Application Oriented Coating Development

FP-24 Effect of hydrogen addition on the residual stress of cubic boron
nitride thin film deposited by UBM sputtering method, J.-S. Ko, J.K.
Park, Korea Institute of Science and Technology, Republic of Korea, J.-Y.
Huh, Unaffiliated, Y.J. Baik (yjbaik@kist.re.kr), Korea Institute of Science
and Technology, Republic of Korea
The effect of hydrogen addition on the formation of cubic boron nitride thin
film was investigated, especially focusing on the behavior of the residual
stress of the film. The films were deposited by UBM (unbalanced
magnetron sputtering) method. A boron nitride target of 3” diameter was
used as a sputtering source, which was connected with 13.56 MHz RF
(radio-frequency) electric power supply. The substrate holder was placed at
7.5 cm under the target and 200 KHz electric power supply was used as a
substrate bias power supply. Either Si or Si wafer with nanocrystalline
diamond thin film on it was used as a substrate. The chamber was evacuated
down to 10 -6 torr and a mixed gas of Ar-10% nitrogen was flowed into the
chamber during deposition. The hydrogen was added to the mixed gas up to
5 sccm while maintaining the total gas flow rate at 20 sccm. The deposition
pressure was maintained at 2 or 4 mtorr. The electric power of the target
was 500 W and the substrate self bias voltage was -60 V. The residual stress
was calculated by Stoney equation by using the curvatures of thin Si strip of
(3 x 40) mm 2 measured during deposition. FTIR, SEM, TEM as well as
RBS were used to analyze the phase, structure and composition.
It was observed that the residual stress was decreased with the increase of
the hydrogen flow, while the cBN fraction was also decreased. The rate of
the decrease, however, has shown different behavior. The former was faster
than the latter at the initial stage of the added hydrogen amount, which
implies that a little addition of the hydrogen could lessened the residual
stress of the film to a much degree with only a trivial decrease of the cBN
fraction. The reason of this behavior was discussed with the incorporation
of Ar atoms into the film and its effect on the formation of the residual
stress.
This research was supported by a grant from the Fundamental R&D
Program for Core Technology of Materials funded by the Ministry of
Knowledge Economy, Republic of Korea.
FP-25 Behavior of cubic boron nitride thin film formation according to
the deposition pressure, E.S. Lee, J.K. Park, Korea Institute of Science
and Technology, Republic of Korea, T.Y. Seong, Korea University,
Republic of Korea, Y.J. Baik (yjbaik@kist.re.kr), Korea Institute of Science
and Technology, Republic of Korea
The formation of cBN is known to be affected mainly by ion energy and
flux. During sputtering process, both the ion energy and the ion flux are a
function of substrate bias voltage and a mean free path of ions. In this study,
the effect of deposition pressure on the formation was investigated to see
the role of the mean free path length in the cBN formation. The films were
deposited by UBM (unbalanced magnetron sputtering) method. A boron
nitride target of 3” diameter was used as a sputtering source, which was
connected with 13.56 MHz RF (radio-frequency) electric power supply. The
substrate holder was placed at 7.5 cm under the target and 200 KHz electric
power supply was used as a substrate bias power supply. Either Si or Si
wafer with nanocrystalline diamond thin film on it was used as a substrate.
The chamber was evacuated down to 1.2 x 10-6 Torr and a mixed gas of
Ar-10% nitrogen was flowed at 20 sccm into the chamber during
deposition. The deposition pressure was varied from 2 to 20 mTorr. For the
system we used, the mean free path length was calculated to be around the
range of the target to the substrate distance. The electric power of the target
was 500 W and the substrate selfbias voltage was varied from -20 to -120
V. FTIR, SEM as well as TEM were used to analyze the phase and
structure.
The formation of the cBN phase was affected both by the substrate bias
voltage and the deposition pressure. There appeared a critical pressure
above which only a hBN phase formed. With increasing the substrate bias
voltage, the critical pressure increased. The cBN content in the FTIR
spectrum was not varied in the range under the critical pressure. The critical
substrate bias voltage was also increased with increasing deposition
pressure. This behavior was discussed with a view point of ion energy and
ion flux ratio relation curve for the cBN formation.
This research was supported by a grant from the Fundamental R&D
Program for Core Technology of Materials funded by the Ministry of
Knowledge Economy, Republic of Korea
FP-26 Effect of moisture adsorption inside the chamber on the
formation of cubic boron nitride thin film, E.S. Lee, J.K. Park, Korea
Institute of Science and Technology, Republic of Korea, T.Y. Seong,
Unaffiliated, Y.J. Baik (yjbaik@kist.re.kr), Korea Institute of Science and
Technology, Republic of Korea
It was reported previously that minor addition of either the oxygen or the
hydrogen had inhibited the formation of cBN during the PVD process. It is,
thus, expected that the moisture adsorbed inside the deposition chamber
could have a harmful effect on the deposition of the cBN film. Such
possibility was investigated in this study. The chamber was open to the
atmosphere before deposition for 1 h under the moisture content of about
30%. Then it was evacuated down to 3.5x 10-6 Torr. It took 30 min to
arrive the pressure and then a mixed gas of Ar-10% nitrogen at 20 sccm was
flown and the deposition process was started. The films were deposited by
UBM (unbalanced magnetron sputtering) method. A boron nitride target of
3” diameter was used as a sputtering source, which was connected with
13.56 MHz RF (radio-frequency) electric power supply. The substrate
holder was placed at 7.5 cm under the target and 200 KHz electric power
supply was used as a substrate bias power supply. Either Si or Si wafer with
nanocrystalline diamond thin film on it was used as a substrate. The
deposition pressure was 4mTorr. We deposited the films for 30 min. Then,
the sample was changed via load lock chamber and the chamber was
evacuated again down to 1.2 x 10 -6 Torr with baking the chamber. The
baking was done by heating the substrate heater whose temperature was
adjusted between room temperature and 500 �. It took 90 min to arrive the
base pressure. It is believed that little moisture was involved into the
chamber during this stage. We compared the FTIR spectra of these samples
to see the effect of moisture contamination.
The first deposited sample has shown that only a hBN phase formed in the
film. The cBN phase began to appear as the deposition batch proceeded.
The number of batch forming the cBN phase was smaller as the baking
temperature increased. The baking time also affected the formation of the
cBN content. We measured the OES (optical emission spectra) during
deposition and compared them from batch to batch to find the possible
indicator of cBN formation. The variation of the intensity of main emission
peak with the number of the batch was shown and their relation with the
cBN formation was discussed.
This research was supported by a grant from the Fundamental R&D
Program for Core Technology of Materials funded by the Ministry of
Knowledge Economy, Republic of Korea
FP-27 Precise modulation of pore diameter of porous anodic alumina
templates by hybrid pulse periods at room temperature, C.K. Chung
(ckchung@mail.ncku.edu.tw), H.C. Chang, S.L. Li, M.W. Liao, National
Cheng Kung University, Taiwan
In the applications of photonic crystal, optic, and photovoltaic, highly
ordered porous anodic aluminum oxide (AAO) is one of famous nanotemplates
as etching mask for pattern transfer and synthesis of
nanocomposite materials. The AAO structural characteristics i.e., pore size
and thickness affected the optical and optoelectronic properties sensitively.
In this article, we proposed a novel synthesis, namely hybrid pulse
anodization (HPA) combined with positive (V+) and negative (V−) voltage
in one pulse period, to fabricate effectively AAO templates using aluminum
foils in 0.5 M oxalic acid at room temperature which is different from
conventional direct-current anodization at low temperature 0~10 °C. The
objective of our research was to study the influence of principal factors,
such as pulse period and applied voltage, on modulating pore diameter (<
100 nm) precisely by HPA. Many researchers demonstrated that the
relationship between voltage and interpore distance was positive. Therefore,
HPA at suitable voltage with different pulse period could produced various
pore diameters, because modulating V− time attracts more or less hydrogen
ions for dissolution of electrolyte/oxide interface. High electrolyte
temperature provides much Joule’s heat for accelerating chemical reaction
of surface, too. It was found that such a method could control mean pore
diameters with difference of about 10 nm. The morphology of surface was
investigated by field-emission scanning electron microscopy for pore size
distribution and regularity analysis. Furthermore, we designed a statistical
experiment using analysis of variance to quantify the effects of these factors
mentioned above on pore diameter variation.
FP-28 Transparent Anti-fingerprint Protective Coatings Prepared by
Duplex Plasma Polymerization, S.W. Chang, Feng Chia University,
Taiwan, C.M. Chen (harlem@pidc.org.tw), Feng Chia University; Plastic
Industry Development Center, Taiwan, J.L. He, Feng Chia University,
Taiwan
Polymeric materials have been widely used as flexible substrates and
housing parts of modern electronic wares. However, their low hardness and
scratch resistance must be improved by additional protective surface
coatings, which require not only mechanical durability but also additional
functions such as surface hydrophobicity, oleophobicity as well as antifingerprint
performance. To satisfy these, a power modulated plasma
polymerization technique was designed to synthesize a transparent
compositional gradient coating on polycarbonate (PC) substrate. Firstly, a
constant flow rate of tetramethyldisiloxane (TMDSO) precursor was
introduced where higher plasma power was employed to deposit a hard H-
C-Si-O bottom layer. The plasma power was then decreased meanwhile
admitting increased fluoromethane (CF4) gas flow as the second precursor to
obtain a top layer with low surface energy. The hard bottom layer acts as a
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