Enhancement of piezoelectric properties of lithium niobate thin films by different annealing parameters

Piezoelectric materials with useful properties find a wide range of applications including opto- and acousto- electronics. Lithium niobate in the form of a thin film is one of those promising materials and has a potential to improve ferroelectric random access memories devices, optical waveguides or acoustic delay lines by virtue of its physical characteristics, e.g. electro-optic coefficient, acoustic velocity, refractive indices etc. The key challenge to overcome is lithium nonstoichiometry as it leads to the appearance of parasite phases and thus aggravates physical and structural properties of a film. According to literature data, in order to obtain microcrystalline piezoelectric phase in previously amorphous films a set of methods is used. In our case we tried to synthesize LN films using congruent target and non-heated silicon substrate and then attain the piezoelectric phase by different annealing parameters. Afterwards LN films were compared to the ones synthesized on the silicon substrate with an additional buffer layer of platinum. Samples were studied by scanning probe microscope. Self-polarization vectors were defined. Based on domain structure images, the histograms of distribution of piezoresponse signals were built.

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Laser-Assisted Etching of Lithium Niobate

MRS Proceedings ◽

10.1557/proc-126-251 ◽

1988 ◽

Vol 126 ◽

Author(s):

Glennis J. Orloff ◽

Steven L. Bernasek ◽

Gary L. Wolk ◽

R. J. Coyle

Keyword(s):

Experimental Data ◽

Chemical Analysis ◽

Lithium Niobate ◽

Rate Equation ◽

Electron Spectroscopy ◽

Optical Waveguides ◽

Etch Rate ◽

Auger Electron ◽

Important Process ◽

Electro Optic

ABSTRACTLaser-assisted dry etching of lithium niobate, LiNbO3, as well as other electro-optic materials could be an industrially important process in the fabrication of optical waveguides. In this investigation, an excimer laser (ArF; 193nm) was used to conduct etching reactions using nitrogen trifluoride, NF3. Enhancement of etching was observed by comparing the etch rate for a gas assisted process with that of a purely photoablative process. Chemical analysis of the etched features via Auger electron spectroscopy and correlation of a simple rate equation with the experimental data revealed that lasersurface interactions are responsible for the laser-assisted etching process.

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Epitaxially induced secondary grain growth in Ti:LiNbO3 optical waveguides

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100154093 ◽

1989 ◽

Vol 47 ◽

pp. 424-425

Author(s):

M. A. McCoy

Keyword(s):

Electron Microscopy ◽

Solid Solution ◽

Transmission Electron Microscopy ◽

Refractive Index ◽

Lithium Niobate ◽

Grain Growth ◽

Optical Waveguides ◽

Waveguide Devices ◽

Transmission Electron ◽

Electro Optic

Lithium niobate (LiNbO3) is one of the most promising materials for use in hybrid optical waveguide devices because of its high electro-optic coefficient and its availability as large single crystals. Optical waveguides in LiNbO3 are most commonly made by Ti indiffusion in which strips of Ti metal (between 10 and 100 nm thick) are deposited on a single crystal LiNbO3 substrate. The device is then heated to temperatures around 1000°C typically for 6 hours. During this time, the Ti diffuses into the LiNbO3 to form a Ti-rich LiNbO3 solid solution. This solid solution has a higher refractive index than the substrate and forms the waveguide region. Factors controlling the indiffusion process, however, are not very well understood and very little is known about the microstructural changes which occur during Ti indiffusion. In this study, the microstructure of Ti:LiNbO3 optical waveguides was examined as a function of time and temperature using transmission electron microscopy (TEM).

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Исследование пьезоэлектрического резонанса в стехиометрических кристаллах LiNbO-=SUB=-3-=/SUB=- в области высоких температур и проводимости

Физика твердого тела ◽

10.21883/ftt.2019.07.47837.375 ◽

2019 ◽

Vol 61 (7) ◽

pp. 1277

Author(s):

М.Н. Палатников ◽

В.А. Сандлер ◽

Н.В. Сидоров ◽

О.В. Макарова

Keyword(s):

Relaxation Time ◽

Dielectric Properties ◽

Lithium Niobate ◽

High Temperatures ◽

Piezoelectric Materials ◽

Conductivity Relaxation ◽

Static Conductivity ◽

Piezoelectric Resonators ◽

Wide Range ◽

Conductivity Relaxation Time

In order to establish conditions of lithium niobate based piezoelectric resonators application at high temperatures and high conductivity in a wide range of temperatures (~ 300 – 850К) we have researched piezoelectric, ferroelectric, dielectric properties and ion conductivity of near-stoichiometric LiNbO3stoich crystals. We have revealed that piezo-resonance is observed in LiNbO3stoich in a certain temperature range ΔТ (correspondingly, in certain static conductivity relaxation time Δtau_V range) and frequencies range Δomega_R provided that tau_V-1<<omegaR. Such patterns are probably applicable not only to LiNbO3stoich crystals, but also to other piezoelectric materials.

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An Integrated Photonic Electric-Field Sensor Utilizing a 1 × 2 YBB Mach-Zehnder Interferometric Modulator with a Titanium-Diffused Lithium Niobate Waveguide and a Dipole Patch Antenna

Crystals ◽

10.3390/cryst9090459 ◽

2019 ◽

Vol 9 (9) ◽

pp. 459 ◽

Cited By ~ 3

Author(s):

Jung

Keyword(s):

Lithium Niobate ◽

Electric Field ◽

Optical Waveguides ◽

Extinction Ratio ◽

Rf Power ◽

Applied Electric Field Strength ◽

Electric Field Sensors ◽

Electric Field Sensor ◽

Electro Optic ◽

Field Sensor

We studied photonic electric-field sensors using a 1 × 2 YBB-MZI modulator composed of two complementary outputs and a 3 dB directional coupler based on the electro-optic effect and titanium diffused lithium–niobate optical waveguides. The measured DC switching voltage and extinction ratio at the wavelength 1.3 μm were ~16.6 V and ~14.7 dB, respectively. The minimum detectable fields were ~1.12 V/m and ~3.3 V/m, corresponding to the ~22 dB and ~18 dB dynamic ranges of ~10 MHz and 50 MHz, respectively, for an rf power of 20 dBm. The sensor shows an almost linear response to the applied electric-field strength within the range of 0.29 V/m to 29.8 V/m.

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Nickel-Indiffusion Waveguide for TE-TM Mode Splitter in Lithium Niobate

International Journal of High Speed Electronics and Systems ◽

10.1142/s012915649700024x ◽

1997 ◽

Vol 08 (04) ◽

pp. 621-642 ◽

Cited By ~ 3

Author(s):

Way-Seen Wang ◽

Yu-Pin Liao ◽

Chih-Hua Yang

Keyword(s):

Lithium Niobate ◽

Optical Waveguides ◽

Propagation Loss ◽

Dispersion Process ◽

Tm Mode ◽

Electro Optic ◽

Dependent Polarization ◽

First Time ◽

Mode Splitter ◽

Versus Concentration

Optical waveguides fabricated by nickel indiffusion on lithium niobate are reviewed. In particular, the fabrication process, index change versus concentration, wavelength dispersion, process-dependent polarization, propagation loss, and electro-optic modulation of the nickel indiffusion waveguide are discussed. To improve the confinement of single-ordinary polarization waveguide fabricated by nickel indiffusion, a novel waveguide made by zinc and nickel indiffusion is presented for the first time. Though the measured propagation loss of the waveguide is larger, the measured output power contours are found more symmetric. Moreover, several TE-TM mode splitters using one or more nickel indiffusion waveguides for the complete mode sorting effect are discussed.

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Laser Deposited Epitaxial Oxide Heterostructures as Prototype Ferroelectric Optical Waveguides

MRS Proceedings ◽

10.1557/proc-285-355 ◽

1992 ◽

Vol 285 ◽

Cited By ~ 5

Author(s):

D. K. Fork ◽

G. B. Anderson

Keyword(s):

Lithium Niobate ◽

Optical Waveguides ◽

Pulsed Laser ◽

Frequency Doubling ◽

Deposition Process ◽

Electro Optic ◽

Out Of Plane ◽

Recent Developments ◽

Laser Sources ◽

Epitaxial Oxide

ABSTRACTThe pulsed laser deposition process is a powerful tool for investigating prototype epitaxial structures. This report outlines recent developments in epitaxial structures which may usefully serve as ferroelectric optical waveguides. Emphasis is given to structures on semiconductor substrates, motivated by hybrid optical/semiconductor integration. Earlier pulsed laser deposited structures, such as BaTiO3/MgO/GaAs (100) are discussed in conjunction with current results on Z-lithium niobate on GaAs (111)A and GaAs (111)B. BaTiO3/MgO/GaAs (100) grows with cube-on-cube crystallography. The epitaxial system z-lithium niobate on GaAs (111)A and GaAs (111)B has been demonstrated both with and without intermediate MgO (111) layers. The in-plane epitaxial relationships are LiNbO3 [110] // GaAs [211] and [211] indicating the existence of 180° boundaries in the LiNbO3 with and without the MgO layer, which grows cube-on-cube with the GaAs. Out-of-plane texture is typically 1.0° and 1.2° for the MgO and LiNbO3 layers respectively. In-plane texture is typically 2.8° and 4.5° for MgO and LiNbO3 layers respectively. These and similar epitaxial systems may be useful for monolithic electro-optic or frequency doubling applications in conjunction with semiconductor laser sources.

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Aurivillius BaBi4Ti4O15 based compounds: Structure, synthesis and properties

Processing and Application of Ceramics ◽

10.2298/pac1303097b ◽

2013 ◽

Vol 7 (3) ◽

pp. 97-110 ◽

Cited By ~ 7

Author(s):

Jelena Bobic ◽

Mirjana Vijatovic-Petrovic ◽

Biljana Stojanovic

Keyword(s):

High Temperature ◽

Bismuth Titanate ◽

Piezoelectric Materials ◽

Random Access ◽

Ferroelectric Materials ◽

Synthesis Methods ◽

Structure Synthesis ◽

Ferroelectric Random Access Memories ◽

Piezoelectric Devices ◽

Barium Bismuth

The discovery of some Aurivillius materials with high Curie temperature or fatigue-free character suggests possible applications in high temperature piezoelectric devices or non-volatile ferroelectric random access memories. Furthermore, increasing concerns for environmental issues have promoted the study of new leadfree piezoelectric materials. Barium bismuth titanate (BaBi4Ti4O15 ), an Aurivillius compound, is promising candidate to replace lead-based materials, both as lead-free ferroelectric and high temperature piezoelectric. In this review paper, we report a detailed overview of crystal structure, different synthesis methods and characteristic properties of barium bismuth titanate ferroelectric materials.

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Ferroelectrics for semiconductor devices

Canadian Journal of Physics ◽

10.1139/p92-188 ◽

1992 ◽

Vol 70 (10-11) ◽

pp. 1159-1170 ◽

Cited By ~ 7

Author(s):

M. Sayer ◽

Z. Wu ◽

C. V. R. Vasant Kumar ◽

D. T. Amm ◽

E. M. Griswold

Keyword(s):

Lead Zirconate Titanate ◽

High Speed ◽

Random Access ◽

Chemical Deposition ◽

Lead Zirconate ◽

Sensors And Actuators ◽

Analog Memory ◽

Electro Optic ◽

Wide Range ◽

Memory Applications

The integration of thin film ferroelectrics with silicon processing is being implemented for various types of devices. The technology is based on the sputtering or chemical deposition of lead-based perovskites such as lead zirconate titanate. Factors concerned with the integration of ferroelectric films with semiconductor processing are described. Major interests in Canada include nonvolatile ferroelectric random access memories for high-speed digital or long-term analog memory applications, high-density capacitors, electro-optic switches, and a wide range of sensors and actuators integrated into silicon.

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Epitaxial ferroelectric thin films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100170591 ◽

1994 ◽

Vol 52 ◽

pp. 572-573

Author(s):

S. G. Ghonge ◽

E. Goo ◽

R. Ramesh ◽

R. Haakenaasen ◽

D. K. Fork

Keyword(s):

Single Crystal ◽

Work Function ◽

Nonvolatile Memory ◽

Ferroelectric Properties ◽

Electrical Contact ◽

Memory Devices ◽

Ferroelectric Films ◽

Si Substrates ◽

Electro Optic ◽

Wide Range

Microstructure of epitaxial ferroelectric/conductive oxide heterostructures on LaAIO3(LAO) and Si substrates have been studied by conventional and high resolution transmission electron microscopy. The epitaxial films have a wide range of potential applications in areas such as non-volatile memory devices, electro-optic devices and pyroelectric detectors. For applications such as electro-optic devices the films must be single crystal and for applications such as nonvolatile memory devices and pyroelectric devices single crystal films will enhance the performance of the devices. The ferroelectric films studied are Pb(Zr0.2Ti0.8)O3(PLZT), PbTiO3(PT), BiTiO3(BT) and Pb0.9La0.1(Zr0.2Ti0.8)0.975O3(PLZT).Electrical contact to ferroelectric films is commonly made with metals such as Pt. Metals generally have a large difference in work function compared to the work function of the ferroelectric oxides. This results in a Schottky barrier at the interface and the interfacial space charge is believed to responsible for domain pinning and degradation in the ferroelectric properties resulting in phenomenon such as fatigue.

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Photonic Crystal Nanobeam Cavities for Nanoscale Optical Sensing: A Review

Micromachines ◽

10.3390/mi11010072 ◽

2020 ◽

Vol 11 (1) ◽

pp. 72 ◽

Cited By ~ 2

Author(s):

Da-Quan Yang ◽

Bing Duan ◽

Xiao Liu ◽

Ai-Qiang Wang ◽

Xiao-Gang Li ◽

...

Keyword(s):

Photonic Crystal ◽

Optical Waveguides ◽

Optical Sensing ◽

Early Stage ◽

Disease Diagnosis ◽

Label Free ◽

Quality Factors ◽

Integrated Sensor ◽

Early Stage Disease ◽

Wide Range

The ability to detect nanoscale objects is particular crucial for a wide range of applications, such as environmental protection, early-stage disease diagnosis and drug discovery. Photonic crystal nanobeam cavity (PCNC) sensors have attracted great attention due to high-quality factors and small-mode volumes (Q/V) and good on-chip integrability with optical waveguides/circuits. In this review, we focus on nanoscale optical sensing based on PCNC sensors, including ultrahigh figure of merit (FOM) sensing, single nanoparticle trapping, label-free molecule detection and an integrated sensor array for multiplexed sensing. We believe that the PCNC sensors featuring ultracompact footprint, high monolithic integration capability, fast response and ultrahigh sensitivity sensing ability, etc., will provide a promising platform for further developing lab-on-a-chip devices for biosensing and other functionalities.

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