Channeling Investigation of the Lattice Location of Ti in Ti-Implanted Optical Waveguides in LiNbO3

1988 ◽  
Vol 100 ◽  
Author(s):  
Ch. Buchal ◽  
S. Mantl ◽  
D. K. Thomas
Keyword(s):  
Optical Waveguides ◽  
Solid Phase ◽  
Lattice Location ◽  
Solid Phase Epitaxy ◽  
X Rays ◽  
Ion Channeling

ABSTRACTIon channeling of 3 MeV He ions has been employed to investigate the lattice location of Ti in Ti implanted optical waveguides in LiNbO3 after Solid Phase Epitaxy. Particle-Induced X-rays (PIXE) from Ti at 4.5 keY (K∝) and Nb at 2.2 keV (L∝β) and 16.6 keV (K∝) have been detected and analyzed simultaneously.All scans yield similar behaviour of the Ti and the Nb signals. This provides clear evidence, that within well annealed implanted waveguides the Ti4+ and the Nb5+ ions occupy equivalent lattice positions.

Optical Waveguide Formation by Ion Implantation of Ti or Ag

1988 ◽  
Vol 100 ◽  
Author(s):  
D. B. Poker ◽  
D. K. Thomas
Keyword(s):  
Ion Implantation ◽  
Concentration Profile ◽  
Optical Waveguides ◽  
Annealing Temperature ◽  
Solid Phase ◽  
Effective Means ◽  
Complete Removal ◽  
Solid Phase Epitaxy ◽  
Annealing Temperatures ◽  
Residual Damage

ABSTRACTIon implantation of Ti into LINbO3 has been shown to be an effective means of producing optical waveguides, while maintaining better control over the resulting concentration profile of the dopant than can be achieved by in-diffusion. While undoped, amorphous LiNbO3 can be regrown by solid-phase epitaxy at 400°C with a regrowth velocity of 250 Å/min, the higher concentrations of Ti required to form a waveguide (∼10%) slow the regrowth considerably, so that temperatures approaching 800°C are used. Complete removal of residual damage requires annealing temperatures of 1000°C, not significantly lower than those used with in-diffusion. Solid phase epitaxy of Agimplanted LiNbO3, however, occurs at much lower temperatures. The regrowth is completed at 400°C, and annealing of all residual damage occurs at or below 800°C. Furthermore, the regrowth rate is independent of Ag concentration up to the highest dose implanted to date, 1 × 1017 Ag/cm2. The usefulness of Ag implantation for the formation of optical waveguides is limited, however, by the higher mobility of Ag at the annealing temperature, compared to Ti.

GROWTH AND CHARACTERIZATION OF EPITAXIAL Si/CoSi2 AND Si/CoSi2/Si HETEROSTRUCTURES

1985 ◽  
Vol 56 ◽  
Author(s):  
B.D. HUNT ◽  
N. LEWIS ◽  
E.L. HALL ◽  
L.G. JTURNER ◽  
L.J. SCHOWALTER ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Growth Temperature ◽  
Molecular Beam ◽  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
Cross Sectional ◽  
Reactive Deposition ◽  
Ion Channeling ◽  
Formation Method

AbstractThin (<200Å), epitaxial CoSi2 films have been grown on (111) Siwafers in a UHV system using a variety of growth techniques including solid phase epitaxy (SPE), reactive deposition epitaxy (RDE), and molecular beam epitaxy (MBE). SEN and TEN studies reveal significant variations in the epitaxial silicide surface morphology as a function of the sillciqd formation method. Pinhole densities are generally greater than 107 cm-2, although some reduction can be achieved by utilizing proper growth techniques. Si epilayers were deposited over the CoSi2 films inthe temperature range from 550ºC to 800ºC, and the reesuulttinng structures have been characterized using SEM, cross—sectional TEN, and ion channeling measurements. These measurements show that the Si epitaxial quality increases with growth temperature, although the average Si surface roughness and the CoSi2 pinhole density also increase as the growth temperature is raised.

scholarly journals Formation of Buried Epitaxial Si-Ge Alloy Layers in Si Crystal by High Dose Ge ION Implantation

1991 ◽  
Vol 235 ◽  
Author(s):  
Kin Man Yu ◽  
Ian G. Brown ◽  
Seongil Im
Keyword(s):  
Ion Implantation ◽  
Single Crystal ◽  
Lattice Mismatch ◽  
Solid Phase ◽  
Metal Vapor ◽  
Ion Source ◽  
Vacuum Arc ◽  
High Dose ◽  
Solid Phase Epitaxy ◽  
Ion Channeling

ABSTRACTWe have synthesized single crystal Si1−xGex alloy layers in Si <100> crystals by high dose Ge ion implantation and solid phase epitaxy. The implantation was performed using the metal vapor vacuum arc (Mevva) ion source. Ge ions at mean energies of 70 and 100 keV and with doses ranging from 1×1016 to to 7×1016 ions/cm2 were implanted into Si <100> crystals at room temperature, resulting in the formation of Si1−xGex alloy layers with peak Ge concentrations of 4 to 13 atomic %. Epitaxial regrowth of the amorphous layers was initiated by thermal annealing at temperatures higher than 500°C. The solid phase epitaxy process, the crystal quality, microstructures, interface morphology and defect structures were characterized by ion channeling and transmission electron microscopy. Compositionally graded single crystal Si1−xGex layers with full width at half maximum ∼100nm were formed under a ∼30nm Si layer after annealing at 600°C for 15 min. A high density of defects was found in the layers as well as in the substrate Si just below the original amorphous/crystalline interface. The concentration of these defects was significantly reduced after annealing at 900°C. The kinetics of the regrowth process, the crystalline quality of the alloy layers, the annealing characteristics of the defects, and the strains due to the lattice mismatch between the alloy and the substrate are discussed.

Heteroepitaxial Growth of Strontium Titanate on Lanthanum Aluminate Using the Metallo-Organic Decomposition Technique.

1993 ◽  
Vol 317 ◽  
Author(s):  
Gabriel Braunstein ◽  
Gustavo R. Paz-Pujalt ◽  
James F. Elman
Keyword(s):  
Solid Phase ◽  
Precursor Solution ◽  
Solid Phase Epitaxy ◽  
Heteroepitaxial Growth ◽  
Potential Influence ◽  
Ion Channeling ◽  
Random Nucleation ◽  
Lanthanum Aluminate ◽  
Organic Precursors ◽  
Organic Decomposition

ABSTRACTWe demonstrate the heteroepitaxial growth of thin films of SrTiO3 prepared by the method of Metallo-organic decomposition on LaAlO3 substrates. The SrTiO3 films are prepared by spin coating and thermal decomposition of a solution of Metallo-organic precursors on single-crystal, <100> oriented, LaAK>3 substrates. Subsequent heat treatment at 1100 – 1200 °C for 1 h results in the epitaxial alignment of the SrTiO3 films with respect to the LaAlO3 substrate.The degree of alignment of the films appears to depend on their thickness, with thinner films showing better alignment (as determined by ion-channeling measurements). This behavior is interpreted as a result of the competition between solid-phase epitaxy and random nucleation, observed during the crystallization of films prepared by Metallo-organic decomposition. However, since thinner films have been prepared by dilution of the precursor solution, there is also the possibility that the concentration of the precursor solution may influence the crystallization behavior of the films.The potential influence of the precursor formulation on the crystallization mechanism is discussed.

Synthesis of Dislocation Free Siy(SnxC1−x)1−y Alloys by Molecular Beam Deposition and Solid Phase Epitaxy

1993 ◽  
Vol 298 ◽  
Author(s):  
Gang He ◽  
Mark D. Savellano ◽  
Harry A. Atwater
Keyword(s):  
Molecular Beam ◽  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
Pure Silicon ◽  
Ion Channeling ◽  
Transmission Electron ◽  
Molecular Beam Deposition ◽  
Beam Deposition

AbstractSynthesis of strain-compensated single-crystal Siy(SnxC1-x)1-y alloy films on silicon (100) substrates has been achieved with compositions of tin and carbon greatly exceeding their normal equilibrium solubility in silicon. Amorphous SiSnC alloys were deposited by molecular beam deposition from solid sources followed by thermal annealing. In situ monitoring of crystallization was done using time-resolved reflectivity. Good solid phase epitaxy was observed for Si0.98Sn0.01C0.01, at a rate about 20 times slower than that of pure silicon. Compositional and structural analysis was done using Rutherford backscattering, electron microprobe, ion channeling, x-ray diffraction, and transmission electron microscopy.

Advanced Ti-Implanted Optical Waveguides in LiNbO3

1986 ◽  
Vol 88 ◽  
Author(s):  
Ch. Buchal ◽  
P. R. Ashley ◽  
D. K. Thomas ◽  
B. R. Appleton
Keyword(s):  
Low Temperatures ◽  
Optical Waveguides ◽  
Crystalline State ◽  
Solid Phase ◽  
Equilibrium Phase ◽  
Planar Waveguides ◽  
Solid Phase Epitaxy ◽  
Low Loss ◽  
Versatile Technique ◽  
Channel Waveguides

ABSTRACTLiNbO3 is the best substrate for modulators and switches for integrated optics. Efficient low loss waveguides for light in LiNbO3 are formed by introducing Ti-ions into its lattice, thus increasing locally the ordinary and the extraordinary indices of refraction. We are the first to use the very versatile technique of ion-implantation to administer Ti into LiNbO3. This implantation process offers the possibility to introduce significantly more Ti into a well-defined volume than conventional diffusion techniques. During this process first an amorphous non-equilibrium phase is generated, which has to be kept at low temperatures in order to prevent segregation. Subsequent thermal treatment leads to solid phase epitaxy and restores the desired stable crystalline state. We have used this technique to fabricate excellent planar waveguides, channel waveguides and Mach-Zehnder modulators.

PZT Electro-Optic Waveguide Devices Fabricated by Solid-Phase Epitaxy

1997 ◽  
Vol 493 ◽  
Author(s):  
Keiichi Nashimoto ◽  
Shigetoshi Nakamura ◽  
Hiroaki Moriyama ◽  
Masao Watanabe ◽  
Eisuke Osakabe
Keyword(s):  
Optical Waveguides ◽  
Solid Phase ◽  
Solution Process ◽  
Propagation Loss ◽  
Metal Alkoxide ◽  
Solid Phase Epitaxy ◽  
Optical Propagation ◽  
Electro Optic ◽  
Pzt Thin Film ◽  
Conductive Substrate

ABSTRACTHigh quality epitaxial PZT optical waveguides have been grown by solid-phase epitaxy based on metal alkoxide solution process. Optical propagation loss was 4 dB/cm in epitaxial PZT thin film optical waveguides grown on SrTiO3 substrates. Epitaxial PZT optical waveguides were grown on Nb doped conductive SrTiO3 substrates, since considerable reduction in drive voltage will be expected when top electrode / optical waveguide / conductive substrate structures are realized. Propagation loss was relatively large, as compared with the structure using non-dope insulative substrates. Preliminary electrooptic deflection devices were fabricated by preparing prism electrodes on the surface of the PZT optical waveguides. Efficient deflection/switching of coupled laser beam in the PZT optical waveguides as large as 26 mrad was observed by applying 70 volts between prism electrode and Nb doped SrTiO3 substrates.

Solid-phase epitaxy of Ti-implanted LiNbO3

1989 ◽  
Vol 4 (2) ◽  
pp. 412-416 ◽  
Author(s):  
D. B. Poker ◽  
D. K. Thomas
Keyword(s):  
Optical Waveguides ◽  
Solid Phase ◽  
Complete Removal ◽  
Amorphous Region ◽  
Liquid Nitrogen Temperature ◽  
High Dose ◽  
Solid Phase Epitaxy ◽  
Complete Recrystallization ◽  
Water Saturated ◽  
Saturated Oxygen

The solid-phase epitaxy of LiNbO3 following ion implantation of Ti dopant for the purpose of producing optical waveguides has been studied. Implanting 360-keV Ti at liquid nitrogen temperature produces a highly damaged region extending to a depth of about 400 nm. This essentially amorphous region can be recrystallized epitaxially by annealing in a water-saturated oxygen atmosphere at temperatures near 400 °C. though complete removal of all irradiation-induced damage requires temperatures in excess of 600 °C. The activation energy of the regrowth is 2.0 eV for implanted fluences below 3 ⊠ 1016 Ti/cm2. At higher fluences the regrowth proceeds more slowly, and Ti dopant segregates at the regrowth interface. Complete recrystallization following high-dose implantation requires annealing temperatures in excess of 800 °C.

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