MBE Growth of Ferroelectric YMnO3 Thin Films on Si(111) Using Y2O3 Buffer Layers

1998 ◽  
Vol 541 ◽  
Author(s):  
Shogo Imada ◽  
Shigeto Shouriki ◽  
Eisuke Tokumitsu ◽  
Hiroshi Ishiwara
Keyword(s):  
Thin Films ◽  
Molecular Beam ◽  
Ferroelectric Properties ◽  
High Energy ◽  
Buffer Layers ◽  
Mbe Growth ◽  
Rocking Curve ◽  
X Ray ◽  
Si Substrates

AbstractA ferroelectric YMnO3 thin films are grown on Si (111) substrates using Y2O3 buffer layers by molecular beam epitaxy (MBE). In-situ reflection high-energy electron diffraction (RHEED) analyses show that both Y2O3 and YMnO3 films are epitaxially grown on Si substrates. X-ray rocking curve measurements also show that the best FWHM (full width at half maximum) values for Y2O3 and YMnO3 films are 0.40° and 0.8°, respectively. C-V characteristics of Al/YMnO3/Y2O3/Si structures indicate the ferroelectric properties of YMnO3 films with a memory window of 0.7V.

Mbe Growth and Thermoelectric Properties OF Bi2Te3 Thin Films

1998 ◽  
Vol 545 ◽  
Author(s):  
Sunglae Cho ◽  
Yunki Kim ◽  
Antonio DiVenere ◽  
George K. L. Wong ◽  
Jerry R. Meyer ◽  
...  
Keyword(s):  
Thin Films ◽  
Antisite Defect ◽  
High Energy ◽  
Layer Growth ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
Mbe Growth ◽  
X Ray ◽  
Crystal Bulk

AbstractWe have grown high quality Bi2Te3 thin films on CdTe(111)B substrates using MBE. Structural properties have been investigated using in-situ reflection high-energy electron diffraction (RHEED) and θ-2θ X-ray diffraction analysis. They show that Bi2Te3films on CdTe(111) grow along the (00.l) in the hexagonal cell with a layer-by-layer growth mode, resulting in a smooth surface, and an X-ray Bragg peak FWHM of 0.2°. The thermopower and electrical conductivity of the stoichiometric Bi2Te3 films were ∼200 μV/K and 103(Ωcm)−1, respectively, comparable to the single crystal bulk values. We have observed the antisite defect effect in Te-rich Bi2Te3films: excess Te occupies Bi lattice sites and behaves as an n-type dopant. Crystallinity and transport properties are strongly affected by non-stoichiometry.

A Study on the Growth of Cubic GaN Films Using an AlGaAs Buffer Layer Grown on GaAs (100) by Plasma-Assisted Molecular Beam Epitaxy

2000 ◽  
Vol 639 ◽  
Author(s):  
Ryuhei Kimura ◽  
Kiyoshi Takahashi ◽  
H. T. Grahn
Keyword(s):  
Molecular Beam Epitaxy ◽  
Buffer Layer ◽  
Molecular Beam ◽  
High Energy ◽  
Rf Plasma ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cubic Gan

ABSTRACTAn investigation of the growth mechanism for RF-plasma assisted molecular beam epitaxy of cubic GaN films using a nitrided AlGaAs buffer layer was carried out by in-situ reflection high energy electron diffraction (RHEED) and high resolution X-ray diffraction (HRXRD). It was found that hexagonal GaN nuclei grow on (1, 1, 1) facets during nitridation of the AlGaAs buffer layer, but a highly pure, cubic-phase GaN epilayer was grown on the nitrided AlGaAs buffer layer.

Properties of Epitaxial SrTiO3 Thin Films Grown on Silicon by Molecular Beam Epitaxy

1999 ◽  
Vol 567 ◽  
Author(s):  
Z. Yu ◽  
R. Droopad ◽  
J. Ramdani ◽  
J.A. Curless ◽  
C.D. Overgaard ◽  
...  
Keyword(s):  
Thin Films ◽  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
High Energy ◽  
State Density ◽  
Unit Cell ◽  
Ex Situ ◽  
Silicon Oxide Layer ◽  
Single Crystalline ◽  
X Ray

ABSTRACTSingle crystalline perovskite oxides such as SrTiO3 (STO) are highly desirable for future generation ULSI applications. Over the past three decades, development of crystalline oxides on silicon has been a great technological challenge as an amorphous silicon oxide layer forms readily on the Si surface when exposed to oxygen preventing the intended oxide heteroepitaxy on Si substrate. Recently, we have successfully grown epitaxial STO thin films on Si(001) surface by using molecular beam epitaxy (MBE) method. Properties of the STO films on Si have been characterized using a variety of techniques including in-situ reflection high energy electron diffraction (RHEED), ex-situ X-ray diffraction (XRD), spectroscopic ellipsometry (SE), Auger electron spectroscopy (AES) and atomic force microscopy (AFM). The STO films grown on Si(001) substrate show bright and streaky RHEED patterns indicating coherent two-dimensional epitaxial oxide film growth with its unit cell rotated 450 with respect to the underlying Si unit cell. RHEED and XRD data confirm the single crystalline nature and (001) orientation of the STO films. An X-ray pole figure indicates the in-plane orientation relationship as STO[100]//Si[110] and STO(001)// Si(001). The STO surface is atomically smooth with AFM rms roughness of 1.2 AÅ. The leakage current density is measured to be in the low 10−9 A/cm2 range at 1 V, after a brief post-growth anneal in O2. An interface state density Dit = 4.6 × 1011 eV−1 cm−2 is inferred from the high-frequency and quasi-static C-V characteristics. The effective oxide thickness for a 200 Å STO film is around 30 Å and is not sensitive to post-growth anneal in O2 at 500-700°C. These STO films are also robust against forming gas anneal. Finally, STO MOSFET structures have been fabricated and tested. An extrinsic carrier mobility value of 66 cm2 V−11 s−1 is obtained for an STO PMOS device with a 2 μm effective gate length.

Bi-Based Superconducting Multilayers Obtained by Molecular Beam Epitaxy

1999 ◽  
Vol 13 (09n10) ◽  
pp. 991-996
Author(s):  
M. Salvato ◽  
C. Attanasio ◽  
G. Carbone ◽  
T. Di Luccio ◽  
S. L. Prischepa ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Xrd Analysis ◽  
High Energy ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray ◽  
Diffraction Model ◽  
Different Thickness

High temperature superconducting multilayers have been obtained depositing Bi2Sr2CuO6+δ(2201) and ACuO2 layers, where A is Ca or Sr, by Molecular Beam Epitaxy (MBE) on MgO and SrTiO3 substrates. The samples, formed by a sequence of 2201/ACuO2 bilayers, have different thickness of ACuO2 layers while the thickness of the 2201 layers is kept constant. The surface structure of each layer has been monitored by in situ Reflection High Energy Electron Diffraction (RHEED) analysis which has confirmed a 2D nucleation growth. X-ray diffraction (XRD) analysis has been used to confirm that the layered structure has been obtained. Moreover, one-dimensional X-ray kinematic diffraction model has been developed to interpret the experimental data and to estimate the period of the multilayers. Resistive measurements have shown that the electrical properties of the samples strongly depend on the thickness of the ACuO2 layers.

Real-time x-ray scattering study of sputter-deposited LaNiO3 thin films on Si substrates

1999 ◽  
Vol 569 ◽  
Author(s):  
Hsin-Yi Lee ◽  
Chih-Hao Lee ◽  
Keng S. Liang ◽  
Tai-Bor Wu
Keyword(s):  
Thin Films ◽  
Real Time ◽  
Amorphous Film ◽  
Amorphous Layer ◽  
Sputtering Deposition ◽  
X Ray ◽  
Si Substrates ◽  
Plane Normal ◽  
Integrated Intensities

ABSTRACTReal-time x-ray reflectivity and diffraction measurements under in-situ sputtering deposition conditions were performed to study the crystallization behavior of LaNiO3thin films on Si substrate. We found that an amorphous layer of 60 Å was grown in the first 6 min of the deposition and subsequently a polycrystalline overlayer was developed as observed from the in-situ x-ray reflectivity curves and diffraction patterns. Polycrystalline columnar textures of (110) and (100) were grown on the top of this amorphous film. By comparing the integrated intensities of two Bragg peaks in the plane normal of x-ray diffraction, it was found that the ability of (100)-texturization enhanced with increasing film thickness over a certain critical value.

Ferroelectric Properties of Epitaxial BiFe0.97Mn0.03O3 Thin Films with Different Crystal Orientations Deposited on Buffered Si Substrates

2009 ◽  
Vol 421-422 ◽  
pp. 111-114
Author(s):  
Hyun Young Go ◽  
Naoki Wakiya ◽  
Takanori Kiguchi ◽  
Tomohiko Yoshioka ◽  
Osamu Sakurai ◽  
...  
Keyword(s):  
Thin Films ◽  
Bismuth Ferrite ◽  
Ferroelectric Properties ◽  
Yttria Stabilized Zirconia ◽  
Buffer Layers ◽  
Laser Deposition ◽  
Stabilized Zirconia ◽  
Si Substrates ◽  
Crystal Orientations ◽  
Mn Doped

We investigated electrical properties of epitaxial Mn doped bismuth ferrite BiFe0.97Mn0.03O3 (BFMO) thin films with different crystal orientations deposited on Si substrates with appropriate buffer layers. Epitaxial SrRuO3 (SRO) thin films with (001), (101), and (111) orientations were grown on CeO2/yttria-stabilized zirconia (YSZ)/Si(001) substrates and YSZ/Si(001), respectively, by the insertion of MgO and TiO2 atomic layers using pulsed-laser deposition (PLD). Using spin coating, we deposited BFMO thin films onto orientated SRO thin films. The BFMO orientation followed the SRO orientation. The Pr values of the BFMO were ordered as follows {111}>{110}>{100}, which is the same as that predicted by crystallographic considerations. The largest Pr value of the {111} orientation is 76 μC/cm2 at 100 kHz, 25°C.

High Tc YBa2Cu3O7−x Thin Films on GaAs-Based Substrate Using MgO Buffer Layers with Sb Passivation Technique 1

1992 ◽  
Vol 275 ◽  
Author(s):  
M. Z. Tseng ◽  
W. N. Jiang ◽  
E. L. Hu ◽  
U. K. Mishra
Keyword(s):  
Molecular Beam ◽  
Full Width Half Maximum ◽  
Ybco Film ◽  
Buffer Layers ◽  
Mbe Growth ◽  
High Tc ◽  
Rocking Curve ◽  
Molecular Beam Epitaxial ◽  
Wet Chemical

ABSTRACTHigh quality YBCO films have been grown on GaAs-based substrates via depositing MgO epitaxial buffer layers prior to YBCO growth. The critical temperature of the best YBCO film, Tc(0) was 87K and Jc>6.7×104 A/cm2 at 77K. The MgO buffer layers are usually [100] oriented along the normal of GaAs (100) substrates with full-width-half-maximum (FWHM) of rocking curve varying from 1–3 degree. We found that the uniformity and quality of MgO buffer layers are very sensitive to the pre-deposition preparation of GaAs-based substrates. Nonuniform MgO buffer layers are often obtained on those substrates prepared by wet chemical processing. Reproducible, controlled formation of the MgO buffer layer was achieved using an antimony passivation scheme, after molecular beam epitaxial (MBE) growth of the desired structure of the substrate.

In situ X-ray characterization of oligophenylene thin films prepared by organic molecular beam deposition

1998 ◽  
Vol 130-132 ◽  
pp. 651-657 ◽  
Author(s):  
Yuji Yoshida ◽  
Hiroshi Takiguchi ◽  
Takeshi Hanada ◽  
Nobutaka Tanigaki ◽  
Eun Mi Han ◽  
...  
Keyword(s):  
Thin Films ◽  
Molecular Beam ◽  
X Ray ◽  
Molecular Beam Deposition ◽  
Beam Deposition

Effect of Interface Manipulation for MBE Growth of AlN on 6H-SiC

2000 ◽  
Vol 622 ◽  
Author(s):  
Koichi Naniwae ◽  
Jeff Hartman ◽  
Chris Petrich ◽  
Robert F. Davis ◽  
Robert J. Nemanich
Keyword(s):  
Molecular Beam ◽  
Film Growth ◽  
High Energy ◽  
Growth Interface ◽  
Mbe Growth ◽  
Aln Film ◽  
Dimensional Growth ◽  
Atomically Flat ◽  
Ammonia Flux

ABSTRACTAlN layers were grown on 6H-SiC(0001) by molecular beam epitaxy using ammonia as the nitrogen source. Clean (√3×√3)R30° SiC surfaces was prepared by in-situ annealing alone and also by in situ annealing consisted of followed by Si deposition and subsequent annealing. The surface morphology of the AlN films observed by AFM was significantly changed by the nucleation procedure. When the AlN growth was initiated with Al flux exposure on a SiC surface prepared by thermal annealing, the surface roughness of the AlN was significantly reduced. Two-dimensional growth of AlN was observed with reflection high-energy electron diffraction from the very beginning. Atomically flat AlN surfaces with a RMS-roughness of ∼0.3 nm were obtained. On the other hand, when film growth was initiated with an ammonia flux exposure on a Si rich SiC surface, a high density of bumps was observed. The bumps seemed to originate from SiNx formation at the heteroepitaxial interface. It was found that control of the Si composition and the V/III ratio at the growth interface is crucial for the AlN film quality.

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