ICMCTF 2012! - CD-Lab Application Oriented Coating Development

PVD is a challenging task. The present work demonstrates a fast and semiquantitative
method for evaluating the coating homogeneity over a large
substrate area. Thin films are deposited using three different PVD
techniques of cathodic arc, DC-sputtering, and High Power Pulsed
Magnetron Sputtering (HPPMS), and compared in terms of the coating
homogeneity and the deposition rate. While the cathodic arc provides a
significantly higher deposition rate compared to the others, similar coating
distributions are achieved among these deposition techniques. The method
presented here contributes towards a fast and efficient optimization of
process parameters for PVD coatings on complex geometries.
10:20am G6-1-8 LPPS hybrid Technologies: New Thermal Spray
Processes for new emerging Energy Applications, H.-M. Hoehle (hansmichael.hoehle@sulzer.com),
Sulzer Metco Europe GmbH, Germany, M.
Gindrat, A. Barth, Sulzer Metco AG (Switzerland), Switzerland
Recent developments in hybrid low pressure thermal spray technologies,
such as Plasma Spray-Thin Film (PS-TF), PS-PVD, PS-CVD are being
increasingly used to develop functional inorganic coatings and films for
emerging high end energy applications. Such applications include
protection layers and electrolytic films in SOFC, gas tight mixed electron
and ion conducting membranes for gas separation and thin functional layers
in photo-voltaic applications. This paper provides a brief overview of the
status of developments of several high end emerging energy applications.
Beside the applications the basics of these technologies will be described.
10:40am G6-1-9 Development of metal strip cooling equipment for
demands of high-rate vacuum coating, J.-P. Heinß (jenspeter.heinss@fep.fraunhofer.de),
P. Lang, Fraunhofer FEP, Germany
Metal strip coating is developing continuously and opens steadily new
application fields. Solar heat and thin film photovoltaic are actual examples.
From economical reasons the electron beam evaporation is predestined to fit
the mass throughput and in the near past a lot of successful developments
became known. Fraunhofer FEP is engaged in developments of vacuum
coating as well as in additional and ambient processes.
High-rate vacuum depositions demand in few cases an effective cooling
concept for scooping out their potential. Otherwise substrate or layer
temperature exhibits the limiting factor. The technical challenge consists in
realizing an effective heat transfer process under high vacuum conditions
and was unsolved up to now. Therefore new cooling equipment for vacuum
metal strip coating was developed. A description of adapted principles and
developed design will be presented. The heat transfer coefficient was
extended outgoing from common cooling drum with 50 up to 200 W/m 2 K
for the new designed cooling equipment. We demonstrate several
dependencies for the heat transfer coefficient and also first results of
adaption of cooling equipment during electron beam deposition of steel
strip.
The increased cooling efficiency opens new technical capabilities:
utilization of very high deposition rates, deposition of thin metal strips and
foils, increase of layer thickness, defining of strip temperature during
deposition up to keeping it constant during high-rate deposition. We discuss
these different performances also in connection with economical
consequences.
11:00am G6-1-10 Multiple frequency coupled plasmas for enhanced
control of PVD processes, S. Bienholz (bienholz@aept.rub.de), E.
Semmler, P. Awakowicz, Ruhr-Universität Bochum, Germany
Capacitively coupled plasmas are widely used in PVD processes over
several years. Classical single radio frequency capacitively coupled plasmas
for PVD processes are nowadays replaced by high rate DC-Magnetron
sputter coaters. Nevertheless, both techniques do not allow a separate
control of ion flux and its energy distribution at the target, which limits the
control range of sputter processes. A possibility to overcome this
constriction consists of exciting the plasma at two or even more different
radio frequencies simultaneously. Whereas high electron densities and
therefore a high ion flux can be achieved by using a very high frequency
(VHF) excitation, a lower frequency (HF) excitation gives a certain control
over the ion bombarding energy at the target. In this contribution we discuss
the possibility of tuning electrical discharge quantities by using multiple
excitation frequencies. Especially, the influence of the relative phase
between one frequency and its second harmonic on the target voltage
waveform and the self bias voltage is investigated, as well as the effect on
relevant plasma quantities. Langmuir probe measurements and optical
emission spectroscopy are performed to fully characterize the plasma. It is
shown, that multiple frequencies capacitively coupled plasmas give an
independent control over ion flux and the ion bombarding energy at the
target over a wide range. The experiments show, that capacitively coupled
multiple frequency plasmas are a promising complement to existing PVD
processes. The authors would like to acknowledge the funding provided by
the ''Deutsche Forschungsgemeinschaft'' within the frame of the SFB-TR 87
and the ''Ruhr University Bochum Research School''.
135 Friday Morning, April 27, 2012