YAG Laser Deposition Research Articles

Pulsed laser deposition of tungsten carbide thin films on silicon (100) substrate

A method of synthesizing tungsten carbide (WC) thin films by a pulsed YAG laser deposition is investigated. WC thin films are deposited on silicon (100) substrates by using WC5%Co alloy targets. Glancing angle X-ray diffraction shows that the strong peaks of W 2C appear at the substrate temperature of 500°C. Beside the strong peaks of W 2C, weak peaks of WC and W 3Co 3C appear at the substrate temperature of 650°C. Auger electron spectroscopy shows that the almost stoichiometric WC films are deposited at the methane gas pressure of 1.0 Pa. Morphological features of the samples have been obtained by employing the technique of scanning electron microscopy. X-ray photoelectron spectroscopy has been used to obtain structural and compositional information about the samples.

CdS thin film deposition by CW Nd:YAG laser

We report cumulative results on CW Nd:YAG laser deposition of CdS thin films. Films are characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, transmission electron microscopy, ultraviolet through visible light transmission, and Raman measurements. Films deposited at 400 °C or higher manifest a pure hexagonal CdS phase, and films deposited at 200 °C or lower contain both cubic and hexagonal phases.

Imaging and gasdynamic modeling of pulsed laser film deposition plumes

Optical multichannel emission spectroscopy and intensified charge-coupled device (ICCD) imaging have been applied to real-time, in situ gas-phase species identification during the pulsed excimer or Nd:YAG laser deposition of various ceramic thin films. A plume gasdynamic expansion model has been developed and used to predict the outer-edge plume front locations for comparison with those observed in the ICCD images. Good agreement was found between the model and ICCD images, with plume temperatures indicated by the model to be typically between 10,000 and 50,000 K. The systems studied include PbZr0.53Ti0.47O3 (PZT), BaTiO3 , AlN, and BN. When high laser fluences were used, ICCD imaging also revealed strong evidence for interactions between the laser and the near-surface plume. Plume particulates were also noted at long times following the laser pulse.

Energy-gap variations in thin laser-deposited Cu(In, Ga) Se 2 films

Thin CuIn x Ga 1 − x Se 2 (0 ≤ x ≤ 1) (CIGS) films were produced by Nd:YAG-laser deposition onto glass substrates. The absorption coefficients and fundamental transition energies of highly oriented CIGS thin films were determined using interferential reflectivity and transmission in the range 400–1700 nm. The energy gaps observed in thin laser-deposited CIGS films near and above the fundamental absorption edge exhibit a nonlinear composition dependence.

Effects of r.f. bias on cubic BN film synthesis by pulsed Nd: YAG laser deposition

A method of synthesizing cubic boron nitride (cBN) films by pulsed Nd:YAG laser deposition was investigated. BN films were deposited on heated (650 °C) Si( 100) substrates using hexagonal BN (hBN) targets. Argon gas was mixed with the reactant nitrogen gas and an r,f. power was applied to the substrate in order to generate a negative d.c. self-bias and enhance the synthesis of the cBN phase. The deposited films were characterized by Fourier transform infrared (FTIR) measurements and Auger electron spectroscopy. FTIR absorption spectroscopy showed that argon ion bombardment with r.f. bias played an important role in the formation of cBN films. Measurements of the optical emission spectrum were performed to estimate the processing plasma state.

Fabrication of CDS Thin Films Using Continuous Wave Laser Evaporation

ABSTRACTWe report new results on continuous wave Nd: YAG laser deposition of Cadmium Sulfide (CdS) thin films. Substrates were soda-lime silicate (SLS) glass, silica glass, silicon, alumina, and copper coated formvar sheets. As-deposited films were characteristically mixtures of cubic and hexagonal phases. X-ray diffraction analysis reveals that two different grain size groups are present. As revealed by SEM micrographs, films had smooth surface morphology. Transmission electron microscopy analysis reveals that grain sizes were extremely small. Also, semiconductive behavior was noted.

パルスYAGレーザデポジション法による窒化ボロン薄膜作製

パルスYAGレーザデポジション法による窒化ボロン薄膜作製

Nanocrystalline YBa 2Cu 4O 8c-oriented films prepared by Nd:YAG laser deposition

Single phase YBa 2Cu 4O 8 films were obtained by Nd:YAG pulsed laser deposition and subsequent annealing. STM / SEM characterization reveal that these films consist of strongly c-oriented nano-sized grains. The observed rather low critical current [ J c (5 K, H = 0) ≃ 1 s ̇ 10 3A/cm 2 ] make these films promising for fast response low field sensor applications.

Magnetism and structure of YBaCuO superconducting films deposited in unusual geometries using Nd:YAG laser

High quality YBa/sub 2/Cu/sub 3/O/sub 7- delta / thin films have been fabricated by pulsed Nd:YAG laser deposition using an unusual off-axis target-substrate geometry. In this geometry, one can eliminate the deposition of laser droplets. The films are free of particles and have smooth surfaces. The critical temperature (T/sub c/) of these films is in the range of 87-90 K, which is as high as that of on-axis deposited films. From the X-ray rocking curve measurement and the magnetization measurement, no significant differences were found between the on-axis and off-axis laser deposited films.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Continous wave Nd:YAG laser deposition of CdS thin films

We report new results on continuous wave Nd:YAG laser deposition of CdS thin films. As-deposited films have optically smooth surfaces and uniform thicknesses. X-ray diffraction measurements indicate that the as-deposited films on glasses are highly oriented with respect to the C-axis. Raman spectrum measurements revealed several longitudinal-optical modes in the films.

CW Nd:YAG Laser Deposition of CdS Thin Films

ABSTRACTThere are two phases of CdS, wurtzite (hexagonal) and zincblende (cubic). To the best of our knowledge there is no report on the growth of large single crystal cubic CdS. Although there have been reports on the vapor deposition of cubic dominated CdS thin films, physical measurements were limited. Substrate material has been considered as the primary factor in attaining the cubic dominated CdS thin films. We report new results on CW Nd:YAG laser deposition of CdS thin films at various temperatures. X-ray diffraction patterns show that the films deposited at 200°C have a dominant cubic phase, those at 400°C being hexagonal. Optical transmission measurements reveal room temperature absorption edges of 515nm and 500nm for films deposited at 200°C and 400°C, respectively. Transmission electron microscopy further reveals differences in crystal structure of the two films. Raman spectra of the cubic film is similar to that of the hexagonal film.