Pulsed Laser Deposition of Laterally Graded X-Ray Optical Multilayers on Substrates of Technical Relevance

1995 ◽  
Vol 382 ◽  
Author(s):  
R. Dietsch ◽  
TH. Holz ◽  
R. Krawietz ◽  
H. Mai ◽  
B. SchÖneich ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Thickness Distribution ◽  
Pulsed Laser ◽  
Single Layer ◽  
Thin Film Deposition ◽  
Optical Quality ◽  
Film Deposition ◽  
Laser Deposition ◽  
Emission Characteristic ◽  
X Ray

ABSTRACTPulsed Laser Deposition (PLD) is used for the preparation of Ni/C, W/C, and Mo/Si multilayers having X-ray optical quality. For the synthesis of layer stacks involving a uniform or a graded thickness distribution across 4"-wafers the conventional thin film deposition equipment of PLD has been modified. This modification provides a precise spatial control of the plasma plume orientation in the deposition chamber. With this arrangement the emission characteristic of the plasma source can be computer controlled and the desired coating profile can be tailored across an extended substrate via a stepper-motor-driven target manipulator.Thus film thickness uniformity (δts < 2%) is obtained on substrates up to 4" diameter even for smaller target-substrate distances. For laterally graded Ni and C individual layers linear thickness gradients of dts/dx = 3.2 × 10−8 were confirmed over the total substrate length by spectroscopic ellipsometry. The parameters deduced from single layer deposition were applied for the synthesis of laterally graded Ni/C multilayers. A mean value of the gradient of the stack period thickness dt/dx = 6.2 × 10−8 confirmed by X-ray reflectometry (nominal value: dt0 /dx = 6.4×10−8 ) characterizes precision and reproducibility of the coating process.

Pulsed Laser Deposition History and Laser-Target Interactions

MRS Bulletin ◽  
1992 ◽  
Vol 17 (2) ◽  
pp. 30-36 ◽  
Author(s):  
Jeff Cheung ◽  
Jim Horwitz
Keyword(s):  
Thin Film ◽  
Laser Beam ◽  
Pulsed Laser Deposition ◽  
Mechanical Energy ◽  
Pulsed Laser ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Laser Deposition ◽  
Small Branch ◽  
The Impact

The laser, as a source of “pure” energy in the form of monochromatic and coherent photons, is enjoying ever increasing popularity in diverse and broad applications from drilling micron-sized holes on semiconductor devices to guidance systems used in drilling a mammoth tunnel under the English Channel. In many areas such as metallurgy, medical technology, and the electronics industry, it has become an irreplaceable tool.Like many other discoveries, the various applications of the laser were not initially defined but were consequences of natural evolution led by theoretical studies. Shortly after the demonstration of the first laser, the most intensely studied theoretical topics dealt with laser beam-solid interactions. Experiments were undertaken to verify different theoretical models for this process. Later, these experiments became the pillars of many applications. Figure 1 illustrates the history of laser development from its initial discovery to practical applications. In this tree of evolution, Pulsed Laser Deposition (PLD) is only a small branch. It remained relatively obscure for a long time. Only in the last few years has his branch started to blossom and bear fruits in thin film deposition.Conceptually and experimentally, PLD is extremely simple, probably the simplest among all thin film growth techniques. Figure 2 shows a schematic diagram of this technique. It uses pulsed laser radiation to vaporize materials and to deposit thin films in a vacuum chamber. However, the beam-solid interaction that leads to evaporation/ablation is a very complex physical phenomenon. The theoretical description of the mechanism is multidisciplinary and combines equilibrium and nonequilibrium processes. The impact of a laser beam on the surface of a solid material, electromagnetic energy is converted first into electronic excitation and then into thermal, chemical, and even mechanical energy to cause evaporation, ablation, excitation, and plasma formation.

Low Temperature Growth of Oriented Gallium Nitride using Pulsed Laser Deposition

1995 ◽  
Vol 395 ◽  
Author(s):  
Robert Leuchtner ◽  
W. Brock ◽  
Y. Li ◽  
L. Hristakos
Keyword(s):  
Pulsed Laser Deposition ◽  
Film Growth ◽  
Ambient Pressure ◽  
Pulsed Laser ◽  
Target Material ◽  
Deposition Process ◽  
Film Deposition ◽  
Laser Deposition ◽  
Metal Target ◽  
X Ray

ABSTRACTOriented GaN has been successfully grown at low substrate temperatures (∼480°C) on a- and r-planes of sapphire, using the pulsed laser deposition process. We have examined the effects of several deposition parameters on film growth, including substrate temperature (∼50–500°C), ambient pressure (1×10−3 – 10 torr of NH3), and target material (Ga or GaN). The film deposition rate was typically ∼3–4 μm/hr. Film characterization was performed using x-ray diffraction (XRD), optical microscopy, x-ray photoelectron spectrometry (XPS), and atomic force microscopy (AFM). In the case of the Ga metal target, a plasma (∼500V) between the target and substrate was necessary to promote formation of the GaN phase. The ammonia ambient enhanced the nitrogen content in the films compared to vacuum deposition. In general, the GaN target yielded better quality films (smaller rocking curve widths and smoother film morphology) compared to the Ga metal target. These results suggest that pulsed laser deposition is a promising approach to fabricating high quality films of this potentially important semiconducting material.

scholarly journals Molybdenum thin films via pulsed laser deposition technique for first mirror application

2012 ◽  
Vol 30 (4) ◽  
pp. 559-567 ◽  
Author(s):  
A.T.T. Mostako ◽  
Alika Khare
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Optical Quality ◽  
Laser Deposition ◽  
X Ray ◽  
Interferometric Technique ◽  
Atomic Force ◽  
Deposition Parameters ◽  
Uv Visible

AbstractMirror like Molybdenum thin films on SS substrate in vacuum (10−3Pa) and in Helium environment has been achieved by Pulsed Laser Deposition (PLD) Technique. The PLD thin films of Molybdenum have been characterized by using X-ray Diffraction (XRD) pattern, Scanning Electron Microscope (SEM), Atomic Force Microscope (AFM) and Energy Dispersive X-ray (EDX). The specular reflectivity was recorded with Fourier Transform Infra-Red spectrometer and UV-Visible spectrometer. The optical quality of the thin films was tested via interferometric technique. At the optimum deposition parameters, the crystal orientation was in Mo(110) phase. The FIR-UV-Visible reflectivity of the mirror was found to be closed to that of the polished bulk Molybdenum and Stainless Substrate (SS) substrate.

Surface and Microstructural Characterization of Homoepitaxial Silicon Grown by Pulsed Laser Deposition

2000 ◽  
Vol 616 ◽  
Author(s):  
J.S. Pelt ◽  
R. Magahñ;a ◽  
M.E. Ramsey ◽  
E. Poindexter ◽  
S. Atwell ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Microstructural Characterization ◽  
Thin Film Deposition ◽  
High Energy ◽  
Film Deposition ◽  
Laser Deposition ◽  
Reliable Technique ◽  
Transmission Electron ◽  
Substrate Temperatures

AbstractThere is a great deal of interest in thin film deposition techniques which can achieve good crystal quality at low substrate temperatures. Pulsed laser deposition (PLD), well-known as a reliable technique for fabrication of high critical temperature superconductor thin films, has a number of characteristics which may make it suitable for such applications. In particular, PLD is characterized by a relatively large average species energy, which can be controlled by the laser fluence at the target. This paper describes the growth of silicon on silicon films using PLD over substrate temperatures between 500 and 700 °C, and in-situ characterization using reflection high-energy electron diffraction (RHEED). Transmission electron microscopy confirms the growth of single crystal oriented films, and atomic force microscopy indicates smooth films with an rms surface roughness of less than 2 Å

Fabrication of Micro Single Chamber Solid Oxide Fuel Cell Using Photolithography and Pulsed Laser Deposition

2015 ◽  
Vol 12 (2) ◽  
Author(s):  
Man Yang ◽  
Zhigang Xu ◽  
Salil Desai ◽  
Dhananjay Kumar ◽  
Jag Sankar
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Solid Oxide ◽  
Laser Deposition ◽  
Oxide Fuel ◽  
Single Chamber

This paper focuses on the fabrication of micro-coplanar interdigitated single chamber solid oxide fuel cell (μ-SC-SOFC) using a combination of micropatterning technique and thin-film deposition technology. Photolithography was used to generate the micro-interdigitated photoresist patterns on the substrates. Pulsed laser deposition (PLD) method was used to deposit thin films of microstructured electrolytes yttrium stabilized zirconia (YSZ) and electrodes (anode: YSZ + NiO and cathode: lanthanum strontium ferrous cobalt (LSCF)). Process parameters were optimized to obtain consistent functional microstructure and crystal morphology. This research shows good potential for combinatorial manufacturing methods to fabricate high quality and repeatable micro fuel cell components.

Sign in / Sign up

Export Citation Format

Share Document