HgTe-CdTe Superlattices Grown by Photo-MOCVD

1986 ◽  
Vol 90 ◽  
Author(s):  
William L. Ahlgren ◽  
J. B. James ◽  
R. P. Ruth ◽  
E. A. Patten ◽  
J.-L. Staudenmann
Keyword(s):  
Cation Vacancy ◽  
X Ray Diffraction ◽  
Third Order ◽  
Cross Sectional ◽  
X Ray ◽  
Target Values ◽  
Diffraction Patterns ◽  
Superlattice Structures ◽  
First Time ◽  
Blocking Mechanism

ABSTRACTHgTe-CdTe superlattices have been grown, for the first time, by photoassisted MOCVD. The substrate temperature was 182°C. Superlattices were obtained despite low growth rates requiring long growth times (∼10 hours). Interdiffusion during growth may be slowed down by growing under saturated Hg vapor to minimize cation-vacancy formation. The nominal superlattice structures were 70Å HgTe-30Å CdTe, 40Å HgTe-40Å CdTe, and similar. Actual superlattice structures were verified by cross-sectional TEM and diffractometer x-ray diffraction patterns. The x-ray diffraction patterns showed satellite peaks up to third order. The actual structures had HgTe layers ∼20% thicker than the nominal (target) values. A grid-like array of dislocations at the substrate-epilayer interface, suggesting operation of a dislocation-blocking mechanism, was observed. Deficiencies in the superlattice growths include a low growth rate, nonuniform layers, high dislocation density (∼108 cm−2 in best layers), and high n-type carrier concentration (∼1018 cm−3 with mobilities up to 3.5 × 104 cm2 V−1 s−1 in the best layer) which may reflect the presence of donor impurities in the material.

scholarly journals The Reliability Improvement of Cu Interconnection by the Control of Crystallizedα-Ta/TaNxDiffusion Barrier

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Wei-Lin Wang ◽  
Chia-Ti Wang ◽  
Wei-Chun Chen ◽  
Kuo-Tzu Peng ◽  
Ming-Hsin Yeh ◽  
...  
Keyword(s):  
Diffusion Barrier ◽  
Practical Application ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Reliability Improvement ◽  
N Concentration ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Interconnection Structure

Ta/TaN bilayers have been deposited by a commercial self-ionized plasma (SIP) system. The microstructures of Ta/TaN bilayers have been systematically characterized by X-ray diffraction patterns and cross-sectional transmission electron microscopy. TaN films deposited by SIP system are amorphous. The crystalline behavior of Ta film can be controlled by the N concentration of underlying TaN film. On amorphous TaN film with low N concentration, overdeposited Ta film is the mixture ofα- andβ-phases with amorphous-like structure. Increasing the N concentration of amorphous TaN underlayer successfully leads upper Ta film to form pureα-phase. For the practical application, the electrical property and reliability of Cu interconnection structure have been investigated by utilizing various types of Ta/TaN diffusion barrier. The diffusion barrier fabricated by the combination of crystallizedα-Ta and TaN with high N concentration efficiently reduces the KRc and improves the EM resistance of Cu interconnection structure.

Organic/Inorganic Superlattices: Structural and Optical Properties

1994 ◽  
Vol 351 ◽  
Author(s):  
Shizuo Tokito ◽  
J. Sakata ◽  
Y. Taga
Keyword(s):  
Diffraction Data ◽  
Copper Phthalocyanine ◽  
Inorganic Materials ◽  
Interface Roughness ◽  
Transmission Electron Micrograph ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Organic Layers ◽  
Diffraction Patterns

ABSTRACTA new class of superlattices consisting of alternating layers of organic and inorganic materials has been prepared from 8-hydroxyquinoline aluminium (Alq), copper phthalocyanine (CuPc), 3,4,9,10-perylenetetracarboxylic diimide (PTCDI) and MgF2 by molecular beam deposition. Small-angle x-ray diffraction data and cross-sectional transmission electron micrograph of the superlattices reveal that the superlattices have layered structure throughout the entire stack. From comparison of the x-ray diffraction patterns, it is found that the interface roughness between organic and MgF2 layers depends on the materials for organic layers. High-angle x-ray diffraction data indicate that there is a structural ordering in the CuPc and PTCDI layers. From the optical absorption and photoluminescence measurements, it is found that the exciton energy of Alq shifts to higher energy with decreasing Alq layer thickness.

Reduced-pressure MOCVD of highly crystalline BaTiO3 thin films

1992 ◽  
Vol 7 (3) ◽  
pp. 542-545 ◽  
Author(s):  
Peter C. Van Buskirk ◽  
Robin Gardiner ◽  
Peter S. Kirlin ◽  
Steven Nutt
Keyword(s):  
Thin Films ◽  
Electron Diffraction ◽  
Total Pressure ◽  
Single Phase ◽  
X Ray Diffraction ◽  
Reduced Pressure ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Diffraction Patterns ◽  
First Time

Epitaxial BaTi3 films have been grown on NdGaO3 [100] substrates by reduced pressure MOCVD for the first time. The substrate temperature was 1000 °C and the total pressure was 4 Torr. Electron and x-ray diffraction measurements indicate highly textured, single phase films on the NdGaO3 substrate which are predominantly [100], with [110] also present. TEM and selected area electron diffraction (SAED) indicate two specific orientational relationships between the [110] and the [001] diffraction patterns.

Microstructural study of MBE-grown ZnO film on GaN/sapphire (0001) substrate

Open Physics ◽  
2008 ◽  
Vol 6 (3) ◽  
Author(s):  
Hua Li ◽  
Jianping Sang ◽  
Chang Liu ◽  
Hongbing Lu ◽  
Juncheng Cao
Keyword(s):  
Interface Layer ◽  
Interfacial Microstructure ◽  
X Ray Diffraction ◽  
Zno Film ◽  
Epitaxial Relationship ◽  
Cross Sectional ◽  
X Ray ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Gan Heterostructure

AbstractSingle crystalline ZnO film is grown on GaN/sapphire (0001) substrate by molecular beam epitaxy. Ga2O3 is introduced into the ZnO/GaN heterostructure intentionally by oxygen-plasma pre-exposure on the GaN surface prior to ZnO growth. The crystalline orientation and interfacial microstructure are characterized by X-ray diffraction and transmission electron microscopy. X-ray diffraction analysis shows strong c-axis preferred orientation of the ZnO film. Cross-sectional transmission electron microscope images reveal that an additional phase is formed at the interface of ZnO/GaN. Through a comparison of diffraction patterns, we confirm that the interface layer is monoclinic Ga2O3 and the main epitaxial relationship should be $$ (0001)_{ZnO} \parallel (001)_{Ga_2 O_3 } \parallel (0001)_{GaN} $$ and $$ [2 - 1 - 10]_{ZnO} \parallel [010]_{Ga_2 O_3 } \parallel [2 - 1 - 10]_{GaN} $$.

Photoinduced structural dynamics of polar solids studied by femtosecond X-ray diffraction

2010 ◽  
Vol 66 (2) ◽  
pp. 168-178 ◽  
Author(s):  
Thomas Elsaesser ◽  
Michael Woerner
Keyword(s):  
Real Time ◽  
Structural Changes ◽  
Bragg Diffraction ◽  
X Ray Diffraction ◽  
Crystalline Materials ◽  
X Ray ◽  
Density Maps ◽  
Diffraction Patterns ◽  
Superlattice Structures ◽  
Work Done

Femtosecond X-ray diffraction allows for real-time mapping of structural changes in condensed matter on atomic length and timescales. Sequences of diffraction patterns provide both transient geometries and charge-density maps of crystalline materials. This article reviews recent progress in this field, the main emphasis being on experimental work done with laser-driven hard X-ray sources. Both Bragg diffraction techniques for bulk and nanostructured single crystals as well as the recently implemented powder diffraction from polycrystalline samples are discussed. In ferroelectric superlattice structures, coherent phonon motions and the driving stress mechanisms are observed in real time. In molecular crystals charge-transfer processes and the concomitant changes of the lattice geometry are analyzed.

Improved powder diffraction patterns for synthetic paranatisite and natisite

2002 ◽  
Vol 17 (3) ◽  
pp. 234-237 ◽  
Author(s):  
S. Ferdov ◽  
V. Kostov-Kytin ◽  
O. Petrov
Keyword(s):  
Data Interpretation ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Diffraction Patterns ◽  
Two Phases ◽  
Xrd Patterns ◽  
First Time

Synthetic analogues of the minerals natisite and for the first time of paranatisite were prepared hydrothermally at 200 °C in the system Na2O–TiO2–SiO2–H2O. The obtained powder x-ray diffraction (XRD) patterns were interpreted by the Powder Data Interpretation (PDI) software package. As a result improved indexing and unit cell parameters refinements of these two phases were achieved. Synthetic natisite is tetragonal, space group—P4/nmm, a=0.649 67(8) nm, c=0.508 45(11) nm, V=0.214 50(10) nm3, Z=2, Dcal=3.13 g.cm−1, F30=37.48, M20=52.79. Synthetic paranatisite is orthorhombic, space group—Pmma, a=0.983 86(29) nm, b=0.919 23(19) nm, c=0.481 84(12) nm, V=0.435 78(19) nm3, Z=1, Dcal=3.01 g.cm−1, F30=16.42, M20=29.21.

Structural Characterization of P-I-N Diode Superlattice Structures Grown on , , and Orientation Si Substrates

1991 ◽  
Vol 220 ◽  
Author(s):  
P. M. Adams ◽  
R. C. Bowman ◽  
V. Arbet-Engols ◽  
K. L. Wang ◽  
C. C. Ahn
Keyword(s):  
Electron Microscopy ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Substrate Orientation ◽  
X Ray ◽  
Si Substrates ◽  
Transmission Electron ◽  
Superlattice Structures ◽  
Strained Layer Superlattices

ABSTRACTP-I-N diodes whose intrinsic region consists of strained layer superlattices (SLS), separated by 40 nm Si spacers, have been grown by MBE on Si substrates with <100>, <110>, and <111> orientations. These structures have been characterized by x-ray diffraction (XRD) and cross-sectional transmission electron microscopy (XTEM). The dual periodicities in these structures produced unique XRD effects and the quality was highly dependent on substrate orientation. The <100> sample was in general free of defects, whereas the <110> and <111> specimens contained significant numbers of twins and dislocations.

Microstructural Studies of Sputtered Co90Fe10/Ag GMR Multilayers

1997 ◽  
Vol 475 ◽  
Author(s):  
J.D. Jarratt ◽  
T.J. Klemmer ◽  
J.A. Barnard
Keyword(s):  
Multilayer Films ◽  
X Ray Diffraction ◽  
Satellite Peak ◽  
Cross Sectional ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Columnar Grains ◽  
Diffraction Patterns ◽  
Microstructural Studies

ABSTRACTThe microstructure of Co90Feio/Ag giant magnetoresistive multilayer films has been investigated using x-ray diffraction (XRD) and cross-sectional transmission electron microscopy. Columnar grains with a (111) fiber growth texture is observed. A comparison is made between the observed layering structure and earlier multilayer schematics based on the literature and magnetic and magnetoresistive measurements as a function of layer thickness. A direct correlation is made between superlattice satellite peak signals from selected area electron diffraction patterns and XRD scans.

X-RAY DIFFRACTION PATTERNS OF DINITROPHENYL DERIVATIVES OF AMINO COMPOUNDS

1952 ◽  
Vol 30 (8) ◽  
pp. 575-580 ◽  
Author(s):  
H. M. Rice ◽  
F. J. Sowden
Keyword(s):  
Powder Diffraction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amino Compounds ◽  
Diffraction Patterns ◽  
First Time ◽  
Derivatives Of

The 2,4-dinitrophenyl derivatives of a number of amino compounds have been prepared and their X-ray powder diffraction measurements made. This appears to be the first time this information has been obtained and it is submitted as a method of identification.

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