Effect of Annealing Temperature on Two-Step Method of GaN Films

2012 ◽  
Vol 629 ◽  
pp. 9-13
Author(s):  
Mei Liu ◽  
Xue You Xu ◽  
Bao Yuan Man ◽  
De Min Kong
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Annealing Temperature ◽  
Laser Energy ◽  
Pulsed Laser ◽  
Nitrogen Atmosphere ◽  
Laser Source ◽  
Step Method ◽  
Experimental Conditions ◽  
Force Microscopy

GaN thin films have been deposited on Si (111) substrates by pulsed laser deposition (PLD) of a GaN target in nitrogen atmosphere. An Nd: YAG pulsed laser with a wavelength of 1064 nm was used as a laser source. The results indicate that the GaN thin films deposited only by PLD are amorphous. By annealing in an NH3 atmosphere, the quality of the GaN thin films is improved, and the crystallzinity GaN thin films were obtained. The influence of annealing temperature on the crystallinity, structure, surface morphology and optical properties of GaN films have been examined by X-ray diffraction (XRD), atomic force microscopy (AFM) and infrared spectrum. In our experimental conditions, the GaN thin films deposited by PLD with a laser energy of 250 mJ, growth temperature of 800 °C and annealed at 1000 °C have the best surface morphology and crystalline quality.

Influence of Post Growth Annealing on the Optical Properties of Gallium Nitride Films Grown by Pulsed Laser Deposition

2012 ◽  
Vol 1432 ◽  
Author(s):  
M. Baseer Haider ◽  
M. F. Al-Kuhaili ◽  
S. M. A. Durrani ◽  
Imran Bakhtiari
Keyword(s):  
Thin Films ◽  
Gallium Nitride ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Nitrogen Atmosphere ◽  
Laser Deposition ◽  
Optical Measurements ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force

Abstract:Gallium nitride thin films were grown by pulsed laser deposition. Subsequently, post-growth annealing of the samples was performed at 400, and 600 oC in the nitrogen atmosphere. Surface morphology of the as-grown and annealed samples was performed by atomic force microscopy, surface roughness of the films improved after annealing. Chemical analysis of the samples was performed using x-ray photon spectroscopy, stoichiometric Gallium nitride thin films were obtained for the samples annealed at 600 oC. Optical measurements of the samples were performed to investigate the effect of annealing on the band gap and optical constants the films.

Effect of Annealing Temperature on Surface Morphology of Lanthanum Phosphate (LaPO4) Nanostructures Thin Films

2012 ◽  
Vol 626 ◽  
pp. 302-305 ◽  
Author(s):  
A.Z. Zainurul ◽  
M. Rusop ◽  
Saifollah Abdullah
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Surface Morphology ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Coating Process ◽  
Force Microscopy ◽  
Lanthanum Phosphate ◽  
Atomic Force ◽  
Eds Analysis

LaPO4 particles with different morphologies and sizes have been successfully synthesized via sol-gel spinned coating process. The aim of this paper is to investigate the effect of annealing on the morphology and formation of LaPO4 on thin films. Physical structural properties of LaPO4 was investigated using atomic force microscopy (AFM-XE100). EDS analysis was done to check on the formation of LaPO4.

XRD study on the effect of the deposition condition on pulsed laser deposition of ZnO films

Open Physics ◽  
2008 ◽  
Vol 6 (3) ◽  
Author(s):  
Bao Man ◽  
Hong Xi ◽  
Chuan Chen ◽  
Mei Liu ◽  
Jing Wei
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Deposition Temperature ◽  
Laser Energy ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Crystalline Quality ◽  
Zno Thin Films ◽  
Laser Source ◽  
Zno Films

AbstractUsing a pulsed laser deposition (PLD) process on a ZnO target in an oxygen atmosphere, thin films of this material have been deposited on Si(111) substrates. An Nd: YAG pulsed laser with a wavelength of 1064 nm was used as the laser source. The influences of the deposition temperature, laser energy, annealing temperature and focus lens position on the crystallinity of ZnO films were analyzed by X-ray diffraction. The results show that the ZnO thin films obtained at the deposition temperature of 400°C and the laser energy of 250 mJ have the best crystalline quality in our experimental conditions. The ZnO thin films fabricated at substrate temperature 400°C were annealed at the temperatures from 400°C to 800°C in an atmosphere of N2. The results show that crystalline quality has been improved by annealing, the optimum temperature being 600°C. The position of the focusing lens has a strong influence on pulsed laser deposition of the ZnO thin films and the optimum position is 59.5 cm from the target surface for optics with a focal length of 70 cm.

scholarly journals Emergence and Evolution of Crystallization in TiO2 Thin Films: A Structural and Morphological Study

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1409
Author(s):  
Ofelia Durante ◽  
Cinzia Di Giorgio ◽  
Veronica Granata ◽  
Joshua Neilson ◽  
Rosalba Fittipaldi ◽  
...  
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Transition Metal Oxides ◽  
Annealing Temperature ◽  
Morphological Properties ◽  
Degree Of Crystallinity ◽  
Tio2 Thin Films ◽  
Force Microscopy ◽  
Heat Treated ◽  
Complementary Techniques

Among all transition metal oxides, titanium dioxide (TiO2) is one of the most intensively investigated materials due to its large range of applications, both in the amorphous and crystalline forms. We have produced amorphous TiO2 thin films by means of room temperature ion-plasma assisted e-beam deposition, and we have heat-treated the samples to study the onset of crystallization. Herein, we have detailed the earliest stage and the evolution of crystallization, as a function of both the annealing temperature, in the range 250–1000 °C, and the TiO2 thickness, varying between 5 and 200 nm. We have explored the structural and morphological properties of the as grown and heat-treated samples with Atomic Force Microscopy, Scanning Electron Microscopy, X-ray Diffractometry, and Raman spectroscopy. We have observed an increasing crystallization onset temperature as the film thickness is reduced, as well as remarkable differences in the crystallization evolution, depending on the film thickness. Moreover, we have shown a strong cross-talking among the complementary techniques used displaying that also surface imaging can provide distinctive information on material crystallization. Finally, we have also explored the phonon lifetime as a function of the TiO2 thickness and annealing temperature, both ultimately affecting the degree of crystallinity.

Influence of Momentary Annealing on the Nanoscale Surface Morphology of Room Temperature Pulsed Laser Deposited NiO(111) Epitaxial Thin Films on Atomically Stepped Sapphire (0001) Substrates

2013 ◽  
Vol 1507 ◽  
Author(s):  
Ryosuke Yamauchi ◽  
Geng Tan ◽  
Daishi Shiojiri ◽  
Nobuo Tsuchimine ◽  
Koji Koyama ◽  
...  
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Room Temperature ◽  
Pulsed Laser ◽  
Film Surface ◽  
Transient State ◽  
Epitaxial Thin Films ◽  
Flat Surfaces ◽  
Surface Nanostructure ◽  
Atomically Flat

ABSTRACTWe examined the influence of momentary annealing on the nanoscale surface morphology of NiO(111) epitaxial thin films deposited on atomically stepped sapphire (0001) substrates at room temperature in O2 at 1.3 × 10−3 and 1.3 × 10−6 Pa using a pulsed laser deposition (PLD) technique. The NiO films have atomically flat surfaces (RMS roughness: approximately 0.1–0.2 nm) reflecting the step-and-terrace structures of the substrates, regardless of the O2 deposition pressure. After rapid thermal annealing (RTA) of the NiO(111) epitaxial film deposited at 1.3 × 10−3 Pa O2, a periodic straight nanogroove array related to the atomic steps of the substrate was formed on the film surface for 60 s. In contrast, the fabrication of a transient state in the nanogroove array formation was achieved with RTA of less than 1 s. However, when the O2 atmosphere during PLD was 1.3 × 10−6 Pa, random crystal growth was observed and resulted in a disordered rough surface nanostructure after RTA.

Epitaxial Growth of AlN Thin Films on Silicon and Sapphire by Pulsed Laser Deposition

1995 ◽  
Vol 395 ◽  
Author(s):  
R.D. Vispute ◽  
H. Wu ◽  
K. Jagannadham ◽  
J. Narayan
Keyword(s):  
Thin Films ◽  
Electrical Resistivity ◽  
Pulsed Laser Deposition ◽  
Laser Energy ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Breakdown Field ◽  
Transmission Electron ◽  
Uv Visible ◽  
Relationship Of

ABSTRACTAIN thin films have been grown epitaxially on Si(111) and Al2O3(0001) substrates by pulsed laser deposition. These films were characterized by FTIR and UV-Visible, x-ray diffraction, high resolution transmission electron and scanning electron microscopy, and electrical resistivity. The films deposited on silicon and sapphire at 750-800°C and laser energy density of ∼ 2 to 3J/cm2 are epitaxial with an orientational relationship of AIN[0001]║ Si[111], AIN[2 110]║Si[011] and AlN[0001]║Al2O3[0001], AIN[1 2 1 0]║ Al2O3[0110] and AIN[1010] ║ Al2O3[2110]. The both AIN/Si and AIN/Al2O3 interfaces were found to be quite sharp without any indication of interfacial reactions. The absorption edge measured by UV-Visible spectroscopy for the epitaxial AIN film grown on sapphire was sharp and the band gap was found to be 6.1eV. The electrical resistivity of the films was about 5-6×l013Ω-cm with a breakdown field of 5×106V/cm. We also found that the films deposited at higher laser energy densities ≥10J/cm2 and lower temperatures ≤650°C were nitrogen deficient and containing free metallic aluminum which degrade the microstructural, electrical and optical properties of the AIN films

Studies of Nanomechanical Properties of Pulsed Laser Deposited NbN films on Si Using Nanoindentation

2012 ◽  
Vol 1424 ◽  
Author(s):  
M. A. Mamun ◽  
A. H. Farha ◽  
Y. Ufuktepe ◽  
H. E. Elsayed-Ali ◽  
A. A. Elmustafa
Keyword(s):  
Thin Films ◽  
Pulsed Laser ◽  
Niobium Nitride ◽  
X Ray Diffraction ◽  
Si Substrate ◽  
Force Microscopy ◽  
Atomic Force ◽  
Wide Range ◽  
Pile Up ◽  
Average Modulus

ABSTRACTNanomechanical and structural properties of pulsed laser deposited niobium nitride thin films were investigated using X-ray diffraction, atomic force microscopy, and nanoindentation. NbN film reveals cubic δ-NbN structure with the corresponding diffraction peaks from the (111), (200), and (220) planes. The NbN thin films depict highly granular structure, with a wide range of grain sizes that range from 15-40 nm with an average surface roughness of 6 nm. The average modulus of the film is 420±60 GPa, whereas for the substrate the average modulus is 180 GPa, which is considered higher than the average modulus for Si reported in the literature due to pile-up. The hardness of the film increases from an average of 12 GPa for deep indents (Si substrate) measured using XP CSM and load control (LC) modes to an average of 25 GPa measured using the DCM II head in CSM and LC modules. The average hardness of the Si substrate is 12 GPa.

Pulsed Laser Deposition (PLD) Technique to Prepare Biocompatible Thin Films

2006 ◽  
Vol 49 ◽  
pp. 56-61 ◽  
Author(s):  
Joseph J. Beltrano ◽  
Lorenzo Torrisi ◽  
Anna Maria Visco ◽  
Nino Campo ◽  
E. Rapisarda
Keyword(s):  
Thin Films ◽  
Pulsed Laser ◽  
Target Material ◽  
Xrd Analysis ◽  
Spot Size ◽  
Laser Deposition ◽  
Laser Source ◽  
Medical Field ◽  
Hot Plasma ◽  
532 Nm

A Nd:YAG laser is employed to ablate different materials useful in the bio-medical field. The laser source operates in the IR (1064 nm), VIS (532 nm) and UV (355 nm) regions with a pulse duration of 3-9 ns, a pulse energy of 3-300 mJ, a spot size of 1 mm2 and a repetition rate of 1- 30 Hz. Target material of interest are Titanium, Carbon, Hydroxyapatite (HA) and Polyethylene (PE). Laser irradiation occurs in vacuum, where hot plasma is generated, and thin films are deposited on near substrates. Generally, substrates of silicon, titanium, titanium-alloys and polymers were employed. Biocompatible thin films are investigated with different surface techniques, such as IR spectroscopy, Raman spectroscopy, XRD analysis and SEM investigations. Depending of the kind of possible application, films require special properties concerning the grain size, porosity, uniformity, wetting, hardness, adhesion, crystallinity and composition. The obtained results will be presented and discussed with particular regard to HA..

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