Pulsed Laser Crystallization of Amorphous Silicon Films: Effects of Substrate Temperature and Laser Shot Density

1992 ◽  
Vol 258 ◽  
Author(s):  
R. I. Johnson ◽  
G. B. Anderson ◽  
S. E. Ready ◽  
D. K. Fork ◽  
J. B. Boyce
Keyword(s):  
Grain Size ◽  
Pulsed Laser ◽  
Laser Shot ◽  
Substrate Bias ◽  
Laser Crystallization ◽  
Film Properties ◽  
X Ray ◽  
Laser Fluences ◽  
High Laser ◽  
Current Report

ABSTRACTA recent report on pulsed laser crystallization of a-Si thin films concluded that substrate bias temperatures up to 400°C in combination with laser fluences below 500 mJ/cm2 had little effect on grain size and transport properties. The current report describes the effects of substrate bias temperature up to 500°C and laser fluence up to 540 mJ/cm2 on grain size, mobility and Si (111) x-ray peak intensities. Results indicate that substrate bias temperatures above 400°C, in combination with high laser shot densities and large laser beam spot energies (> 500 mJ/cm2), are a factor in Improving these film properties.

Growth of Textured Nanocrystalline Cobalt Ferrite Thin Films by Pulsed Laser Deposition

2008 ◽  
Vol 8 (8) ◽  
pp. 4135-4140 ◽  
Author(s):  
Lakshmikanta Aditya ◽  
A. Srivastava ◽  
S. K. Sahoo ◽  
P. Das ◽  
C. Mukherjee ◽  
...  
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Pulsed Laser Deposition ◽  
Cobalt Ferrite ◽  
Pulsed Laser ◽  
Grazing Incidence ◽  
Orientation Distribution ◽  
Laser Deposition ◽  
X Ray ◽  
Ferrite Thin Films

Cobalt ferrite thin films have been deposited on fused quartz substrates by pulsed laser deposition at various substrate temperatures, TS (25 °C, 300 °C, 550 °C and 750 °C). Single phase, nanocrystalline, spinel cobalt ferrite formation is confirmed by X-ray diffraction (XRD) for TS ≥ 300 °C. Conventional XRD studies reveal strong (111) texturing in the as deposited films with TS ≥ 550 °C. Bulk texture measurements using X-ray orientation distribution function confirmed (111) preferred orientation in the films with TS ≥ 550 °C. Grain size (13–16 nm for TS ≥ 300 °C) estimation using grazing incidence X-ray line broadening analysis shows insignificant grain growth with increasing TS, which is in good agreement with grain size data obtained from transmission electron microscopy.

DEPOSITION OF TiAlV THIN FILMS BY PULSED LASER AND DC MAGNETRON SPUTTERING: STRUCTURAL, COMPOSITIONAL AND ELECTROCHEMICAL CORROSION STUDY

2019 ◽  
Vol 27 (08) ◽  
pp. 1950188
Author(s):  
A. ALKHAWWAM ◽  
B. ABDALLAH ◽  
A. K. JAZMATI ◽  
M. TOOTANJI ◽  
F. LAHLAH
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Corrosion Test ◽  
Pulsed Laser ◽  
Electrochemical Corrosion ◽  
Target Material ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
Film Properties ◽  
X Ray

In this work, TiAlV thin films have been prepared on two different types of substrates: silicon and stainless steel (SS304) by two deposition methods: Pulsed Laser Deposition (PLD) and DC magnetron sputtering. Different techniques have been employed in order to characterize film properties such as: Scanning Electron Microscopy (SEM) equipped with Energy Dispersive X-ray (EDX), X-ray diffraction (XRD), microhardness and corrosion test. EDX analysis showed that the deposited films are slightly different from that of the target material Ti6Al4V alloy. The measured microhardness values are about 11.7[Formula: see text]GPa and 4.7[Formula: see text]GPa for films prepared by PLD and DC magnetron sputtering, respectively. Corrosion test indicated that the corrosion resistance of the two TiAlV films deposited on SS304 substrates in (0.9% NaCl) physiological normal saline medium was significantly improved compared with the SS304 substrates. These attractive results could permit applications of our films in the medical implants fabrication.

Properties of DLC Films Produced by Pulsed Laser Induced Arc Deposition

2005 ◽  
Vol 475-479 ◽  
pp. 3901-3904
Author(s):  
Na-na Jiang ◽  
Tian Min Shao ◽  
Da Rong Chen
Keyword(s):  
Pulsed Laser ◽  
Substrate Bias ◽  
Film Properties ◽  
Spectra Analysis ◽  
Substrate Bias Voltage ◽  
Arc Voltage ◽  
Atomic Force ◽  
Pre Treatment ◽  
Arc Deposition ◽  
Si Wafer

Diamond like carbon (DLC) films were prepared on Si wafer, using laser induced arc deposition (Laser arc) technique. Results of Raman Spectra analysis showed that the as-deposit films were amorphous, having obvious sp3 structure. Meanwhile, surface topography and micro-tribological properties were investigated by using Atomic Force Microscope and Nano-Scratch Tester. Influences of arc voltage, substrate bias voltage, target materials and substrate pre-treatment methods upon the film structures and film properties were studied.

Microstructure of CuInS2 films prepared by sulfuration of Cu–In–O films

1993 ◽  
Vol 8 (3) ◽  
pp. 545-550 ◽  
Author(s):  
Takahiro Wada ◽  
Takayuki Negami ◽  
Mikihiko Nishitani
Keyword(s):  
Grain Size ◽  
Deposition Temperature ◽  
Single Phase ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Chalcopyrite Structure ◽  
Microstructural Properties ◽  
X Ray ◽  
Gas Atmosphere ◽  
Scanning Electron

Polycrystalline CuInS2 thin films are prepared by sulfuration of Cu–In–O films. The Cu–In–O films are deposited from a sintered Cu2In2O5 target by using a pulsed laser deposition (PLD) method. Then, the Cu–In–O films are converted into CuInS2 films by means of a subsequent annealing in an H2S gas atmosphere. The characteristics of the films are determined by using an x-ray diffractometer (XRD), an energy dispersive x-ray spectrometer (EDX), and a scanning electron microscope (SEM). The effects of the deposition and sulfuration temperatures of the Cu–In–O films on the structural and microstructural properties of CuInS2 films are examined experimentally. Single-phase CuInS2 films with a chalcopyrite structure are obtained when Cu–In–O films are sulfurated at a temperature higher than 400 °C. Grain size of CuInS2 is larger when a lower deposition temperature and a higher sulfuration temperature of Cu–In–O films are employed.

scholarly journals Analysis of Direct Optical Ablation and Sequent Thermal Ablation for the Ultrashort Pulsed Laser Photo-Thermal Micromachining

Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1151
Author(s):  
Chang-Wei Xiong ◽  
Ching-Yen Ho ◽  
Dong-Kai Qiao
Keyword(s):  
Laser Fluence ◽  
Thermal Effects ◽  
Thermal Ablation ◽  
Pulsed Laser ◽  
Processing Quality ◽  
Laser Fluences ◽  
High Laser ◽  
High Laser Fluences ◽  
Ultrashort Pulsed Laser ◽  
Residual Heat

An ultra-fast pulsed laser for materials processing can obtain submicrometer- to nanometer-sized parts or patterns (precision or accuracy) because the heat cannot diffuse in time for an ultra-fast pulsed duration, and this causes a threshold of ablation in multi-photoabsorption. The optical and thermal effects significantly affect the processing quality of an ultrashort pulsed laser for materials. This study utilizes a Laplace transform method to display the optical and thermal effects on the temperature field and the ablated depth of an ultrashort pulsed laser processing of materials. The results reveal that If an ultrafast pulsed laser-induced heat can keep the irradiated region above the evaporated temperature until the thermal diffusion occurs in the lattice of materials, thermal ablation occurs. The optical ablation can get a better processing quality due to less thermal diffusion. This study theoretically elucidates that the depth of optical ablation approximates the product of an optical absorption length and the logarithm of the ratio of laser fluence to laser fluence threshold. It has also been shown that the optical and thermal ablation, respectively, occur in low and high laser fluence because the optical ablation depends directly on the main source of the incident ultrashort pulsed laser. However, the thermal ablation is determined by the residual heat directly from the incident ultrashort pulsed laser after the optical ablation. The increase rate of the ablated depth per pulse with laser fluence is actually lower at high laser fluences than that at low laser fluences because the thermal ablation using the residual heat directly from the incident ultrashort pulsed laser is governed at high laser fluences. This study will provide the closed-form of a solution that elucidate the direct optical ablation and sequent thermal ablation for the ultra-fast pulsed laser photo-thermal processing.

Growth of TiO2 Thin Films by Pulsed Laser Evaporation

1990 ◽  
Vol 191 ◽  
Author(s):  
Ming Y. Chen ◽  
P. Terrence Murray
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Pulsed Laser ◽  
Grazing Incidence ◽  
Ex Situ ◽  
Laser Evaporation ◽  
Tio2 Thin Films ◽  
Film Properties ◽  
X Ray

ABSTRACTThin films of TiO2 have been grown by pulsed laser evaporation. The films were analyzed by in-situ Auger and x-ray photoelectron spectroscopy as well as by ex-situ grazing incidence xray diffraction. Films grown at room temperature and at a pressure of 5×10minus; 3 Torr were oxygen deficient. Films grown at 500°C and higher were found to be stoichiometric TiO2.The effect of substrate temperature and evaporation conditions on film properties will be discussed.

The Effects of Substrate Temperature and Bias on the Structural, Mechanical and Tribological Properties of TiC films deposited by Magnetron Assisted Pulsed Laser Deposition

2001 ◽  
Vol 697 ◽  
Author(s):  
A.R. Phani ◽  
J.E. Krzanowski ◽  
J.J. Nainaparampil
Keyword(s):  
Substrate Temperature ◽  
Pulsed Laser Deposition ◽  
Tribological Properties ◽  
Room Temperature ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Indentation Hardness ◽  
Substrate Bias ◽  
X Ray ◽  
Mechanical And Tribological Properties

AbstractTitanium carbide films have been deposited using a hybrid magnetron sputtering/ pulsed laser deposition technique. One set of films was deposited at substrate temperatures ranging from room temperature to 600oC with no substrate bias, and a second set was deposited at 400°C bias voltages up to -150V. X-ray diffraction, X-ray photoelectron spectroscopy, and electron microscopy were employed for structural and compositional characterization of the films, and nano-indentation hardness testing and pin-on-disc wear tests were used to evaluate the mechanical and tribological properties. All the TiC films deposited without substrate bias were highly crystalline. The films deposited with bias had significantly reduced crystallinity and non-stoichiometric film compositions. The hardness of the TiC films increased with substrate temperature from 8 GPa at room temperature to 18 GPa at 600oC, whereas the biased films had a maximum hardness of 12 GPa. The wear test data showed significantly lower friction and longer wear life for the -150V biased film.

The Influence of Target-Substrate Bias on Pulsed Laser Deposited Yba2Cu307-6

1989 ◽  
Vol 169 ◽  
Author(s):  
D.B. Chrisey ◽  
J.S. Horwitz ◽  
K.S. Grabowski ◽  
M.E. Reeves ◽  
M.S. Osofsky ◽  
...  
Keyword(s):  
Thin Films ◽  
Pulsed Laser ◽  
Substrate Bias ◽  
Film Properties ◽  
Positive Ions ◽  
Composition Structure

AbstractWe have deposited YBa2Cu307.$ thin films onto <100> SrTi03 substrates at 700°C as a function of target‐substrate bias (0 to 300 V) in order to make use of the positive ions in the laser produced plume to assist in the deposition. The films were extensively characterized to determine differences in film properties (composition, structure, and transport). The results suggest that film properties were optimized at or near a target‐substrate bias of 100 V, although, the differences in film properties were within the margin of reproducibility.

Aluminum Nitride Thin Films Grown by Plasma-Assisted Pulsed Laser Deposition on Si Substrates

1997 ◽  
Vol 468 ◽  
Author(s):  
M. Okamoto ◽  
T. Ogawa ◽  
Y. Mori ◽  
T. Sasaki
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Laser Energy ◽  
Pulsed Laser ◽  
Atomic Ratio ◽  
Laser Deposition ◽  
X Ray ◽  
Si Substrates ◽  
High Laser ◽  
High Laser Energy

ABSTRACTThe smooth and highly oriented AlN films were obtained using pulsed laser deposition from sintered AlN target in a nitrogen ambient. The XRD investigation revealed that highly oriented AlN thin films along the c-axis (AlN (0002)) normal to the substrate were obtained both on Si(111) and on Si(100) substrates. The (0002) x-ray peak width became narrower with increasing substrate temperature. The CL investigation showed that AlN films at high laser energy density (Ed) indicated CL peak at shorter wavelength (306nm) than that at low Ed (394nm). N/Al atomic ratio in AlN films grown at high Ed also increased as comparison with the films grown at low Ed.

Aspects of microanalysis in a transmission electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 510-511
Author(s):  
R. Sinclair ◽  
B.E. Jacobson
Keyword(s):  
Grain Size ◽  
Electron Beam ◽  
Electron Microscope ◽  
Chemical Analysis ◽  
Transmission Electron Microscope ◽  
Vapor Deposition ◽  
Critical Currents ◽  
X Ray ◽  
Fine Grain ◽  
Transmission Electron

INTRODUCTIONThe prospect of performing chemical analysis of thin specimens at any desired level of resolution is particularly appealing to the materials scientist. Commercial TEM-based systems are now available which virtually provide this capability. The purpose of this contribution is to illustrate its application to problems which would have been intractable until recently, pointing out some current limitations.X-RAY ANALYSISIn an attempt to fabricate superconducting materials with high critical currents and temperature, thin Nb3Sn films have been prepared by electron beam vapor deposition [1]. Fine-grain size material is desirable which may be achieved by codeposition with small amounts of Al2O3 . Figure 1 shows the STEM microstructure, with large (∽ 200 Å dia) voids present at the grain boundaries. Higher quality TEM micrographs (e.g. fig. 2) reveal the presence of small voids within the grains which are absent in pure Nb3Sn prepared under identical conditions. The X-ray spectrum from large (∽ lμ dia) or small (∽100 Ǻ dia) areas within the grains indicates only small amounts of A1 (fig.3).

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