Papers by Valentin Craciun
Report on Alternative Buffer Layer Technologies - Year II
Transparent and conducting indium tin oxide thin films grown by pulsed laser deposition at low temperatures
OPTOELECTRONICS AND ADVANCED MATERIALS-RAPID COMMUNICATIONS
ABSTRACT
Thin Solid Films, 2004
Very thin HfO films were deposited directly on Si substrates by the pulsed laser deposition techn... more Very thin HfO films were deposited directly on Si substrates by the pulsed laser deposition technique in a wide range of 2 substrate temperatures and oxygen pressures to investigate the kinetics of the interfacial layer formation. Angle-resolved X-ray photoelectron spectroscopy (XPS) investigations showed that the interfacial layer formed between the Si substrate and the deposited oxide contains a mixture of HfO and SiO without any strong evidence to support the formation of a silicate-type 2 2 compound. X-Ray reflectivity measurements showed that the mass density of the interfacial layer is higher than that of pure SiO , while spectroscopic ellipsometry measurements showed that the refractive index is higher than that of pure SiO , therefore 2 2 corroborating the XPS results.
Growth of dense SiC films on Si at medium temperatures by pulsed laser deposition
Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 2001
Thin SiC films were grown on (100) Si substrates by the pulsed laser deposition technique at medi... more Thin SiC films were grown on (100) Si substrates by the pulsed laser deposition technique at medium temperatures. The influence of the substrate temperature, from 550 to 700 °C, and of the laser repetition rate upon film composition and optical properties has been investigated. Using a 2.5 J/cm2 laser fluence and a 10 Hz repetition rate, dense and finely crystalline SiC films exhibiting very good optical properties and containing less than 2% oxygen were grown at a substrate temperature of only 700 °C.
Application of ultraviolet radiation to minimize interfacial layer formation during the growth of alternate high-k gate dielectrics on Si
MRS Proceedings, 2001
ABSTRACTYttrium oxide and barium strontium titanate (BST) thin films were grown directly on Si su... more ABSTRACTYttrium oxide and barium strontium titanate (BST) thin films were grown directly on Si substrates by the pulsed laser deposition (PLD) technique. Because the optimum oxygen pressure during PLD process is of the order of 10 mTorr, some of the oxygen atoms are trapped inside the grown films and contribute to the growth of a silicon oxide interfacial layer. The use of an UV source during the growth resulted in the reduction of the optimum oxygen pressure and, as a consequence, the amount of trapped oxygen and thickness of the interfacial layer. In addition to that, UV radiation influenced the film morphologies and electrical properties. A further reduction of the interfacial layer was obtained on substrates that were exposed prior to deposition to NH3 for short periods of time under UV radiation.
Letter Growth of ZnO thin films on GaAs by pulsed laser deposition
ABSTRACT
Influence of LiMn2O4 film and particle morphology on electrochemical properties of Li ion rechargeable batteries
Reference LTP-CONF-2000-001View record in Web of Science Record created on 2005-01-12, modified o... more Reference LTP-CONF-2000-001View record in Web of Science Record created on 2005-01-12, modified on 2016-08-08
Low temperature growth of smooth indium tin oxide films by ultraviolet assisted pulsed laser deposition
Journal of Optoelectronics and Advanced Materials
ABSTRACT
Proceedings of the EMRS 2011 Spring Meeting Symposium D: Synthesis, Processing and Characterization of Nanoscale Multi Functional Oxide Films III Preface
Thin Solid Films
Symposium on Advances in Laser and Lamp Processing of Functional Materials
<title>Self-aligned synthesis of titanium silicide by multipulse excimer laser irradiation</title>
Advanced Techniques for Integrated Circuit Processing, 1991
ABSTRACT
Investigation of pulsed laser annealing (PLA) and rapid thermal annealing (RTA) of CIGS films and solar cells
Conference Record of the Thirty-first IEEE Photovoltaic Specialists Conference, 2005.
Studies of the effect of pulsed laser annealing (PLA) and rapid thermal annealing (RTA) on Cu(In,... more Studies of the effect of pulsed laser annealing (PLA) and rapid thermal annealing (RTA) on Cu(In,Ga)Se2 (CIGS) films and devices under various annealing conditions are reported in this paper. Several characterizations were carried out before and after each annealing. The results show that both of these two techniques could positively benefit the CIGS film properties and device performance.
MRS Proceedings, 2001
ZnS:Ag phosphor particles were encapsulated with nano-meter thick films of indium tin oxide (ITO)... more ZnS:Ag phosphor particles were encapsulated with nano-meter thick films of indium tin oxide (ITO) in order to slow the degradation process of the phosphor as well as to reduce the amount of sulfur species out-gassing from the phosphor. Cathodoluminescent (CL) degradation measurements were performed at two different vacuum conditions (6.1–10-7 Torr and 1–10-5 Torr). The CL degradation curves showed that the ITO coating improved the brightness lifetime. X-ray photoelectron spectroscopy was used to determine the chemical changes on the coated and uncoated degraded particle surfaces. CL images were used to show the loss of brightness from the surface of the phosphor particles. Then energy dispersive x-ray spectroscopy was used to measure the ratio of the area under the zinc and sulfur peaks on an atomic weight %, which showed a loss in sulfur during the degradation experiments.
EMRS 2011 Fall meeting symposium on Stress, structure and stoichiometry effects on nanomaterials Preface
Applied Surface Science, 2012
<title>Surface nitride/oxynitride layers obtained by multipulse excimer laser irradiation of metal and semiconductor samples</title>
1st Intl School on Laser Surface Microprocessing, 1990
ABSTRACT
Highly conducting indium tin oxide films grown by ultraviolet-assisted pulsed laser deposition at low temperatures
Thin Solid Films, 2004
ABSTRACT
Materials Science and Engineering: B, 1993
Reactive pulsed laser deposition has been used to deposit thin TiN films on Si substrates. The la... more Reactive pulsed laser deposition has been used to deposit thin TiN films on Si substrates. The layers were stoichiometric TiN, with very low O contamination and exhibited a smooth, featureless surface. This new method can easily be applied to the growth of other important nitrides such as ZrN, Wn, HfN or the deposition of multilayer structures such as TiN-Ti on a variety of substrates.
Direct oxinitride synthesis by multipulse excimer laser irradiation of silicon wafers in a nitrogen-containing ambient environment
Journal of Applied Physics, 1990
The direct synthesis of silicon oxinitride films by multipulse excimer (λ=308 nm) laser irradiati... more The direct synthesis of silicon oxinitride films by multipulse excimer (λ=308 nm) laser irradiation in a nitrogen-containing ambient gas is reported featuring characteristics consistent with potential application in microelectronics.
Titanium silicide synthesis as an effect of cw CO2-laser irradiation
Journal of Applied Physics, 1989
The synthesis of TiSi2 was obtained by continuous wave CO2-laser scanning of a two-layer structur... more The synthesis of TiSi2 was obtained by continuous wave CO2-laser scanning of a two-layer structure of polycrystalline silicon and titanium on a silicon base. The characterization studies were performed by Rutherford backscattering, scanning electron microscopy, and four-point probe measurements. It was shown that the silicon cap layer prevents the oxidation of the titanium film and couples better the infrared laser radiation to the base due to its lower reflectivity, thus profitably enhancing processing efficiency.
Microstructure of oxidized layers formed by the low-temperature ultraviolet-assisted dry oxidation of strained Si0.8Ge0.2 layers on Si
Journal of Applied Physics, 1994
Ultraviolet-assisted low-temperature (550 °C) dry oxidation of Si0.8Ge0.2 strained layers on (100... more Ultraviolet-assisted low-temperature (550 °C) dry oxidation of Si0.8Ge0.2 strained layers on (100)Si has been studied. The oxidation rate of this material was found to be a factor of 2 greater than that of pure Si oxidation under identical irradiation conditions. Initially, the structure of the oxidized material consists of a SiO2 layer on top of a strained Si1−xGex layer with a Ge concentration significantly higher (x≳0.2) than the initial value. Increasing the oxidation time produces more SiO2 and a Si1−xGex layer further enriched with Ge. However, the oxidation rate is reduced and some of the Ge becomes trapped inside the growing SiO2 layer. For a prolonged irradiation time (≳5 h) SiGe oxidation still continues, unlike the case for pure Si, while the Ge trapped inside the SiO2 forms isolated microcrystalline regions.
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Papers by Valentin Craciun