Abstract: Ta-Al-N thin films on Si wafer were prepared by RF reactive magnetron sputtering in a
N2/Ar ambient. Then the stacked structures of Cu/Ta-Al-N/Si were prepared and annealed at
temperatures varied from 400°C to 900°C for 5 minutes in a N2 ambient tube. Four-point probe (FPP)
sheet resistance measurement, Atomic force microscope (AFM), Scanning electron
microscope(SEM), Alpha-Step IQ Profilers and X-ray Diffraction(XRD) were used to investigate the
composition, morphology and the diffusion barrier properties of the thin films. The results show that
with the increasing of Al component, the surface of Ta-Al-N thin-films became finer, the sheet
resistance became higher, and after annealing at 800°C/300S FA, Cu diffusion through Ta-Al-N
barrier didn’t not occurred. Results show that Ta-Al-N thin-films could act as diffusion barrier for
new generation integrated circuits due to its excellent high temperature properties.
Abstract: Orthorhombic Bi2S3 (bismuthinite) nanorods and nanowires were synthesized by the
solventless thermolysis of bismuth alkylthiolate precursors. Reactions producing high aspect ratio
nanowires were carried out in air at 225°C with the presence of a capping ligand species, octanoate.
Nanorods with a lower aspect ratio were produced by the same approach with the addition of
elemental sulfur at a lower temperature (~160°C). Current density –Voltage characterization of the
devices under illumination with 500 W Xenon lamp showed the photovoltaic performance. Both the
nanorods and the nanowires hybrid with the polymer show the improved photovoltaic performance
than polymer only. As far as we know, we are the first to apply Bi2S3 nanorods and nanowires to solar
cells with the structure of ITO/PEDOT:PSS/MDMO-PPV:Bi2S3/Al.
Abstract: The practical uses of soft magnetic composite(SMC) for an electrical motor is presented in
this paper. SMC allows obtaining improved stator and core shapes as well as totally new design
concepts such as claw pole motor. However, a major disadvantage of soft magnetic composites was
their weak strength. In this study, spark plasma sintering (SPS) was utilized to improve the strength
of SMC. Advantages of the SPS process over other conventional sintering process are the faster
heating and cooling rates ensured and higher pressure applied during the sintering procedure. This
allows obtaining high strength products in short periods of time to meet with industrial application
without insulation destruction. This paper introduces the development of high strength soft magnetic
composite motor core and examples of practical application for industries. The result showed that the
SPS process increased the fracture strength, about 1.3 to 1.7 times, of SMC compare to the
conventional compaction. Also we derive method to reduce the iron loss in the SPS sintering process
using control forming temperature. As the forming temperature decreased from 500°C to 300°C,
reduction of iron-loss was obtained from 192W/kg to 21W/kg by using SPS sintering process.
Moreover, with increased the SPS sintering process pressure value from 250MPa to 800MPa which is
the conventional compaction condition and decreased forming temperature to 200°C, iron-loss was
measured. The results showed that iron-loss was obtained 11.42W/kg and it was similar value of
conventional compaction results.
Abstract: Diamond coatings on pure titanium substrates are of interest for tribological and
biomedical implants. However, due to the different thermal expansion coefficients of the two
materials, the complex nature of the interlayer formed during diamond deposition, and the difficulty
in achieving very high nucleation density, it is hard to deposit adherent thin diamond layers on
titanium. The aim of the present research was to successfully produce smooth and well adherent
nanocrystalline diamond (NCD) film on a pure Ti substrate using the microwave plasma chemical
vapor deposition (MWPCVD) method. The influence of Argon addition to CH4/H2 plasma on the
crystallinity, morphology and growth of the diamond film deposited by MWPCVD was investigated
using field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), Xray
diffraction (XRD) and Raman spectroscopy.
Abstract: SiO2 coatings and double layer films of SiO2/Si3N4 have been designed and prepared on
sapphire (α-Al2O3) by radio frequency magnetron reactive sputtering in order to improve the optical
and mechanical properties of infrared windows of sapphire. The transmission of the coated and
uncoated sapphire in the wavelength range from 2.5 to 6.7um was determined. Surface morphology
and roughness of coated and uncoated sapphire have been measured using a talysurf. The flexure
strength of coated and uncoated sapphire samples has been studied by 3-point bending tests at room
temperature and high temperatures. The results show that the coatings can improve the surface
morphology and reduce the surface roughness of sapphire substrate. What’s more, the designed single
layer of SiO2 film and two-layer of SiO2/Si3N4 films can both increase the transmission of sapphire in
mid-wave IR and strengthen sapphire at high temperatures. Coated sapphire transmits over 95% at
wavelength from 3 to 5um for the two designs. Flexure tests reveal that SiO2 coatings and SiO2/Si3N4
films increase the strength of c-axis sapphire by a factor of about 1.5 and 1.4, respectively, at 800°C.
Abstract: Amorphous Si films are generally deposited on glass by physical or chemical vapor
deposition. When annealed, they undergo crystallization through nucleation and grain growth. At
low annealing temperatures, crystallization starts near the glass substrates for pure Si films and near
metals for metal-induced crystallization. In this case, crystallites grow along the <111> directions of
c-Si nearly parallel to the film plane, that is, the directed crystallization. The directed crystallization
is likely to develop the <110> or <111> orientation, which means the <110> or <111> directions
are along the film thickness direction. As the annealing temperature increases, equiaxed
crystallization tends to increase, which in turn increases random orientation. When the annealing
temperature is further increased, the <111> orientation may be obtained.
Abstract: This paper reports that Zn ion implantation to a dose of 1 × 1017 ions/cm2 was performed on
highly c-axis-orientated ZnO thin films deposited on Si (100) substrates by the sol-gel technique.
After ion implantation, the as-implanted ZnO films were annealed in argon ambient at different
temperatures from 300−500 oC. The effects of ion implantation and post-implantation annealing on
the structural and luminescent properties of the ZnO films were investigated by x-ray diffraction,
photoluminescence (PL). Results show that the intensities of (002) peak and photoluminescence (PL)
were evidently decreased by Zn ion implantation. The recovery of (002) peak and photoluminescence
occurs at ~300oC.
Abstract: Carbon doped TiO2 and pure TiO2 thin films were prepared by atmospheric metal organic
chemical vapor deposition (MOCVD) method. Both pure TiO2 and carbon doped TiO2 films are in
anatase structure. X-ray photoelectron spectra (XPS) of the carbon doped TiO2 film indicate carbon
atoms occupy oxygen sites and form Ti-C bonds in TiO2 lattice. In UV-VIS absorption spectra, it can
be found that the carbon doped TiO2 film has a red-shifted absorption edge compared with the pure
TiO2 film. In the photocatalytic decomposition experiment of Rh.B, carbon doped TiO2 exhibited
remarkably visible light activity.
Abstract: This paper discusses the effect of plating condition on the mechanical properties and
residual stress of electroplated Cu film. The inlaid copper structure was fabricated on silicon wafer
where silicon oxide was thermally grown. Seed layer was deposited by sputtering method followed by
copper electro-deposition. Copper was electrodeposited with IBM paddle type electroplating machine
Residual stress, hardness, elastic modulus, and surface roughness of electroplated copper film were
investigated at various organic additives in plating solution and current types with a nanoindenter and
a surface profilometer. The dishing amounts in chemical mechanical polishing (CMP) was also
investigated at various additives. The results show that, in the case of residual stress, the copper film
deposited at higher additive or PC current result in lower residual stress. The additives do not
significantly affect the mechanical properties of Cu deposit.