Structural and optical transformations by laser irradiation of InSb-based thin films

The effect of 647 nm Kr-ion laser irradiation on small, 1 μm diameter regions of (In0.43Sb0.57)0.87Ge0.13 and In0.43Sb0.57 amorphous as-deposited thin alloy films was determined. Laser irradiation times of 50 ns-20 μs produced three distinct reflectivity states which differed from the original as-deposited values for both alloys. Both alloys exhibited an amorphous state of increased reflectivity after short pulse (∼100 ns to ∼500 ns) laser irradiation which has not been previously observed. Slightly longer pulses caused surface corrugations to form in these high reflectivity regions. The formation of corrugations was consistent with stress relaxation. Further laser annealing caused crystallization and decreased reflectivity. The addition of Ge increased the minimum time to crystallize by one order of magnitude, inhibited the precipitation of pure Sb crystals, and caused crystallites to nucleate at the spot edge rather than from the center of the spot. Optical, microstructure, and electrical changes were correlated. SEM and TEM showed that regions of similar reflectivity could result from significantly different microstructures.

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Laser Irradiation of InSb:Ge Thin Films

MRS Proceedings ◽

10.1557/proc-152-129 ◽

1989 ◽

Vol 152 ◽

Author(s):

K. A. Rubin ◽

C. Ortiz ◽

J. Solis ◽

K. Roche

Keyword(s):

Thin Films ◽

Laser Irradiation ◽

Laser Annealing ◽

Ion Irradiation ◽

Short Pulse ◽

Amorphous State ◽

Alloy Films ◽

Ion Laser

ABSTRACTThe effect of 647nm Kr-ion laser and 514.5 nm Ar-ion irradiation on 1 and 7 μm diameter regions, respectively, of (In43Sb57)87 Ge13 thin alloy films was determined. Laser irradiation times of 50ns - 20μs produce different reflectivity states. An amorphous state of increased reflectivity with respect to the as-deposited amorphous state was produced only with the smaller beam after short pulse (∼100ns to ∼500ns) laser irradiation. Slightly longer pulses caused formation of surface corrugations. The corrugation morphology occurred in the nanosecond regime both in air and vacuum. Further laser annealing caused crystallization and decreased reflectivity. The crystallization microstructures were random cellular for the irradiation in air. Irradiation in vacuum produced three, distinct concentric structures.

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Monitoring explosive crystallization phenomenon of amorphous silicon thin films during short pulse duration XeF excimer laser annealing using real-time optical diagnostic measurements

Thin Solid Films ◽

10.1016/j.tsf.2006.05.046 ◽

2006 ◽

Vol 515 (4) ◽

pp. 1651-1657 ◽

Cited By ~ 27

Author(s):

Chil-Chyuan Kuo ◽

Wen-Chang Yeh ◽

Jia-Bin Chen ◽

Jeng-Ywan Jeng

Keyword(s):

Thin Films ◽

Amorphous Silicon ◽

Pulse Duration ◽

Laser Annealing ◽

Short Pulse ◽

Excimer Laser Annealing ◽

Short Pulse Duration ◽

Silicon Thin Films ◽

Optical Diagnostic ◽

Explosive Crystallization

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LASER-INDUCED PROCESS OF BINARY ALLOYING OF Ge–Se

Surface Review and Letters ◽

10.1142/s0218625x99000251 ◽

1999 ◽

Vol 06 (02) ◽

pp. 219-223

Author(s):

S. K. BHADRA ◽

T. BANDYOPADHYAY ◽

A. K. MAITI ◽

K. GOSWAMI

Keyword(s):

Thin Films ◽

Optical Absorption ◽

Composite Film ◽

Laser Irradiation ◽

Laser Fluence ◽

Optical Absorption Spectra ◽

Compound Formation ◽

Argon Ion Laser ◽

Ion Laser ◽

Argon Ion

Thin films of chalcogenides are synthesized by CW argon ion laser irradiation of separate Ge/Se and Se/Te film sandwiches according to near stoichiometric proportions. The compound formation and crystalline transition of amorphous Se film are characterized by observing photomicrographs and optical absorption spectra. The composite film of bilayer Ge/Se does not form compounds but deposits as separate elements under equivalent laser fluence.

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Phase Transition of GeSbTe Thin Films Induced by Thermal Treatment and Laser Irradiation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.750-752.1048 ◽

2013 ◽

Vol 750-752 ◽

pp. 1048-1051

Author(s):

Jing Chen ◽

Fei Yang ◽

Ling Xu ◽

Liang Tong ◽

Jun Xu ◽

...

Keyword(s):

Thin Films ◽

Laser Irradiation ◽

Irradiation Time ◽

Amorphous State ◽

Annealing Treatment ◽

Electron Beam Evaporation ◽

Nitrogen Atmosphere ◽

Face Centered Cubic ◽

Si Substrates ◽

Fcc Phase

GeSbTe (GST) thin films were deposited on Si substrates using electron beam evaporation system and then annealed in nitrogen atmosphere at different temperatures. X-ray diffraction (XRD) and Atomic Force Microscope (AFM) measurements were used to characterize as-deposited and annealed films. Annealing treatment was found to induce changes in microstructure, surface roughness, grain size and so on, indicating that with the increase of annealing temperature, the amorphous state of GST materials change first to face-centered-cubic (fcc) phase state and finally to the stable hexagonal (hex) state. Amorphous Ge1Sb2Te4film will crystallize under laser irradiation. With increasing irradiation time or irradiation power, the degree of crystallization increases. The Raman spectra of thin film shows three peaks after laser irradiation, the peaks can be attributed to the key vibrations which were caused by crystallization. With the irradiation time increases, the peaks shift.

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Excimer (XeCl) Laser Annealing of PbZr0.4Ti0.6O3 Thin Film at Low Temperature for TFT FeRAM Application

MRS Proceedings ◽

10.1557/proc-830-d3.6 ◽

2004 ◽

Vol 830 ◽

Cited By ~ 1

Author(s):

W. X. Xianyu ◽

H. S. Cho ◽

J. Y. Kwon ◽

H.X. Yin ◽

T. Noguchi

Keyword(s):

Thin Film ◽

Thin Films ◽

Energy Density ◽

Laser Irradiation ◽

Excimer Laser ◽

Laser Annealing ◽

Laser Energy ◽

Perovskite Phase ◽

Hysteresis Loops ◽

Xecl Laser

ABSTRACTIn this study, we successfully produced PbZr0.4Ti0.6O3 (PZT (40/60)) thin films with high crystallinity and high remnant polarization (Pr) at low process temperatures using pulsed excimer (XeCl) laser irradiation. In our experiments, amorphous PZT films were prepared on Pt/Ti/SiO2/Si substrates by a sol-gel method. A two-step process was used to crystallize the amorphous thin films: the films were annealed at 550°C for 10 min to initiate the nucleation of the PZT perovskite phase, and then annealed with an excimer laser heating at 400°C in a 120 Torr nitrogen gas atmosphere. Laser energy density was varied from 150 to 750 mJ/cm2 per pulse. x-ray diffraction (XRD) patterns show that 150–200 mJ/cm2 range multi-shot excimer laser irradiation drastically improved the crystallinity of the PZT perovskite phase, and FESEM photographs show that the PZT thin film has uniform-sized crystal grains. The ferroelectric properties were found to depend on the laser energy density and shot number. Before the laser annealing, the films show hysteresis loops with low Pr and the loops do not saturate. After laser annealing, the films show highly saturated hysteresis loops, with the Pr increasing from 2.2 μC/cm2 to 23.0 μC/cm2. We also propose a new technology for fabrication of thin film transistor (TFT)-driven FeRAM devices on arbitrary insulator substrate such as on glass.

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Stress Relaxation and the Formation of Silicides in the Process of the Crystallization of NI-NB Films on SI

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100088804 ◽

1991 ◽

Vol 49 ◽

pp. 898-899

Author(s):

N. Rozhanski ◽

V. Lifshitz

Keyword(s):

Thin Films ◽

Stress Relaxation ◽

Integrated Circuits ◽

Direct Evidence ◽

Alloy Film ◽

Diffusion Barriers ◽

Effective Barrier

Thin films of amorphous Ni-Nb alloys are of interest since they can be used as diffusion barriers for integrated circuits on Si. A native SiO2 layer is an effective barrier for Ni diffusion but it deformation during the crystallization of the alloy film lead to the appearence of diffusion fluxes through it and the following formation of silicides. This study concerns the direct evidence of the action of stresses in the process of the crystallization of Ni-Nb films on Si and the structure of forming NiSi2 islands.

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Microstructure of YBa2Cu3O7-x thin films deposited by dc sputtering

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100152835 ◽

1989 ◽

Vol 47 ◽

pp. 172-173

Author(s):

O. Eibl ◽

G. Gieres ◽

H. Behner

Keyword(s):

Thin Films ◽

Cross Sections ◽

Intermediate Layer ◽

Amorphous State ◽

Critical Currents ◽

Dc Sputtering ◽

State Process ◽

Diffraction Patterns ◽

Film Substrate ◽

Substrate Temperatures

The microstructure of high-Tc YBa2Cu3O7-X thin films deposited by DC-sputtering on SrTiO3 substrates was analysed by TEM. Films were either (i) deposited in the amorphous state at substrate temperatures < 450°C and crystallised by a heat treatment at 900°C (process 1) or (ii) deposited at around 740°C in the crystalline state (process 2). Cross sections were prepared for TEM analyses and are especially useful for studying film substrate interdiffusion (fig.1). Films deposited in process 1 were polycristalline and the grain size was approximately 200 nm. Films were porous and the size of voids was approximately 100 nm. Between the SrTiO3 substrate and the YBa2Cu3Ox film a densly grown crystalline intermediate layer approximately 150 nm thick covered the SrTiO3 substrate. EDX microanalyses showed that the layer consisted of Sr, Ba and Ti, however, did not contain Y and Cu. Crystallites of the layer were carefully tilted in the microscope and diffraction patterns were obtained in five different poles for every crystallite. These patterns were consistent with the phase (Ba1-XSrx)2TiO4. The intermediate layer was most likely formed during the annealing at 900°C. Its formation can be understood as a diffusion of Ba from the amorphously deposited film into the substrate and diffusion of Sr from the substrate into the film. Between the intermediate layer and the surface of the film the film consisted of YBa2Cu3O7-x grains. Films prepared in process 1 had Tc(R=0) close to 90 K, however, critical currents were as low as jc = 104A/cm2 at 77 K.

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