Growth and Characterization of CuInSe2 Epitaxial Films for Device Applications

1996 ◽  
Vol 426 ◽  
Author(s):  
S. Niki ◽  
T. Kurafuji ◽  
P. J. Fons ◽  
I. Kim ◽  
O. Hellman ◽  
...  
Keyword(s):  
Lattice Mismatch ◽  
Free Exciton ◽  
Epitaxial Films ◽  
Cross Sectional ◽  
Residual Defect ◽  
Transmission Electron ◽  
Large Lattice ◽  
Device Applications ◽  
Large Lattice Mismatch ◽  
Lattice Matched

AbstractCuInSe2 (CIS) epitaxial layers have been grown on both GaAs (001) and In0.29Ga0.71 As pseudo lattice-matched substrates by molecular beam epitaxy, and characterized for device applications. Despite a large lattice mismatch of Δa/a˜2.2%, epitaxial growth of CuInSe2 has been demonstrated on GaAs (001) showing their film properties strongly dependent on the Cu/In ratio. In-rich films had a large number of twins on {112} planes, and were found to be heavily compensated. On the other hand, Cu-rich films showed distinct photoluminescence emissions indicating significantly higher film quality in comparison with In-rich films. Two dimensional reciprocal x-ray intensity area mapping and cross-sectional transmission electron microscopy showed the formation of an interfacial layer in the vicinity of the CuInSe2/GaAs interface resulting from the strain-induced interdiffusion between CuInSe2 and GaAs. Reduction in lattice mismatch to Δa/a˜0.2% by using In0.29Ga0.71As pseudo lattice-matched substrates made possible the growth of high quality CuInSe2 with predominant free exciton emissions in their photoluminescence spectra and with residual defect densities of as low as p˜l×1017cm-3 implying the growth of device quality CuInSe2 epitaxial films.

Characterization of Interfacial Structure in Large Lattice Mismatch Heteroepitaxy: Ag/Si (111)

1990 ◽  
Vol 209 ◽  
Author(s):  
D.C. McKenna ◽  
G.-C. Wang ◽  
K. Rajan
Keyword(s):  
Lattice Mismatch ◽  
Interfacial Structure ◽  
Epitaxial Relationship ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Interfacial Structures ◽  
Large Lattice ◽  
Large Lattice Mismatch ◽  
Diffraction Patterns

ABSTRACTThe interfacial structure of a large lattice mismatched (˜25%) (111) Ag-Si system was studied by using transmission electron diffraction (SADP - Selected Area Diffraction Pattern). The epitaxial films of Ag (600–1200Å) were grown by MBE on flat Si(111) and misoriented Si(1ll) surfaces. We have examined the interfacial structures of the Ag on 2° misoriented Si(111) using diffraction patterns of cross sectional view. Through a detail analysis of thelocation and shape of the diffraction spots, we can determine the epitaxial relationship between Ag and Si, the small tilt angle of Ag(111) planes withrespect to the misoriented Si(111), the period of the finite terrace size of the misoriented Si substrate, and the size of the ordered region in the Ag film. The O-lattice analysis developed by Bollmann has beenapplied to this interface andthe result is compared with the SADP observation.

Structural Studies of an InAs-GaAs Superlattice Alloy

1985 ◽  
Vol 47 ◽  
Author(s):  
M. C. Tamargo ◽  
R. Hull ◽  
L. H. Greene ◽  
J. R. Hayes ◽  
N. Tabatabaie ◽  
...  
Keyword(s):  
Lattice Mismatch ◽  
Layer Structure ◽  
Growth Conditions ◽  
Buffer Layers ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Large Lattice ◽  
Large Lattice Mismatch ◽  
Strained Layer Superlattices ◽  
Lattice Matched

ABSTRACTThin alternating layers of InAs and GaAs have been grown by MBE on buffer layers lattice matched to InP. The layer structure was evaluated by transmission electron microscopy (TEM) and low angle X-ray scattering. Commensurate epitaxial layers approximately 15Å thick were obtained in spite of the large lattice mismatch (7%). These results and their implication for growth conditions of strained-layer superlattices will be discussed.

Effect of Substrate Misorientation on Heteroepitaxy with Large Lattice Mismatch: Ag/Si(111)

1989 ◽  
Vol 160 ◽  
Author(s):  
D.C. McKenna ◽  
K.-H. Park ◽  
G.-C. Wang ◽  
G.A. Smith
Keyword(s):  
Misorientation Angle ◽  
Lattice Mismatch ◽  
Epitaxial Films ◽  
Misalignment Angle ◽  
Si Substrates ◽  
Ion Channeling ◽  
Flat Substrate ◽  
Surface Normal ◽  
Large Lattice ◽  
Large Lattice Mismatch

AbstractEpitaxial films of Ag(111) were grown by Molecular Beam Epitaxy (MBE) on small angle misoriented Si(111) substrates. The surface normal was tilted 0 to 6° away from the Si(111) axis toward the [112] direction. The structure of the films was analyzed by x-ray diffraction and MeV He+ ion channeling. Despite a large lattice mismatch, good quality epitaxial films, 600–1200 Å thick, were grown on the misoriented Si substrates. Interestingly, the angle between the Si(111) axis of the substrate and the Ag(111) axis of the film (the misalignment angle) is not zero. In contrast to the perfect alignment on a flat substrate, the Ag(111) axis is tilted away from the Si(111) axis toward the surface normal. Axial MeV He+ ion channeling shows the misalignment angle (up to .6°) increases with substrate misorientation angle (~1/10 substrate misorientation angle).

Transmission electron microscopy observation and optical property of sol-gel derived LiNbO3 films

1996 ◽  
Vol 11 (12) ◽  
pp. 3152-3157 ◽  
Author(s):  
K. Terabe ◽  
A. Gruverman ◽  
Y. Matsui ◽  
N. Iyi ◽  
K. Kitamura
Keyword(s):  
Lattice Mismatch ◽  
Sol Gel ◽  
Misfit Dislocations ◽  
Microscopy Observation ◽  
Continuous Film ◽  
Transmission Electron ◽  
Large Lattice ◽  
Large Lattice Mismatch ◽  
Interface Structures ◽  
Optical Waveguiding

Crystallization behavior, defects, and interface structures of sol-gel derived LiNbO3 films on three kinds of substrates were examined. The nucleation was found to occur epitaxially at the interface between the film and the substrate. The continuous film is formed by coalescence of the island-like crystallites. When sapphire substrate is used, which has large lattice mismatch with the LiNbO3, the resulting film contains a large amount of micropores, twin structures, and misfit dislocations. On the other hand, while LiTaO3 and 5% MgO-doped LiNbO3 substrates with smaller mismatch are used as substrates, the films show no evidence of the formation of dislocations and twins. The film on 5% MgO-doped LiNbO3 substrate shows better optical waveguiding property.

Unique Defect-Induced Donor Structure at the Lattice Mismatched InAs/GaP Heterointerface

1998 ◽  
Vol 535 ◽  
Author(s):  
V. Gopal ◽  
E.-H. Chen ◽  
E. P. Kvam ◽  
J. M. Woodall
Keyword(s):  
Lattice Mismatch ◽  
Misfit Dislocations ◽  
High Electron ◽  
Epitaxial Relationship ◽  
Band Gap Engineering ◽  
Large Lattice ◽  
Device Applications ◽  
Direct Growth ◽  
Large Lattice Mismatch ◽  
Hall Sensors

AbstractWe have investigated the direct growth of narrow-gap InAs on wide-gap GaP by Molecular Beam Epitaxy. InAs and GaP have the largest mismatch among all the III-arsenides and the III-phosphides – 11%. A perfect epitaxial relationship is maintained between the InAs and the GaP despite the large lattice mismatch. Moreover, a reproducible defect structure with unique electronic properties is developed at the heterointerface. A point defect associated with the intersection of 90° misfit dislocations may act as an ordered, structural dopant. This dopant is fully ionized with a constant, high sheet carrier density of 1013 cm−2, independent of InAs layer thickness, and exhibits no freeze out even at 5 K. Device applications for such a system include temperature insensitive Hall sensors. We have also demonstrated high electron mobilities (over 10000 cm2/V-sec) in nominally undoped thick InAs layers grown on GaP. The explanation of this effect is presented to emphasize the exciting possibilities of band gap engineering in this system.

Structural Effects in Al(111)/Si(111) Heteroepitaxy by Partially Ionized Beam Deposition α

1988 ◽  
Vol 116 ◽  
pp. 465-470 ◽  
Author(s):  
A. S. Yapsir ◽  
C.-H. Choi ◽  
S. N. Yang ◽  
T.-M. Lu ◽  
M. Madden ◽  
...  
Keyword(s):  
Single Crystal ◽  
Lattice Mismatch ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
Atom Ratio ◽  
Transmission Electron ◽  
Large Lattice ◽  
Large Lattice Mismatch ◽  
Partially Ionized ◽  
Acceleration Voltage

AbstractSingle crystal Al(111) films were grown on Si(111) surface at room temperature under a conventional vacuum condition using the partially ionized beam (PIB) deposition technique. The Al films were deposited with an ion to atom ratio of about 0.3% and an acceleration voltage of 1 kV. Transmission electron microscopy (TEM) analysis showed that the as-deposited films were single crystal with certain density of dislocation networks. These dislocations disappeared following a heat treatment at 450°C for 30 min. From X-ray diffraction and TEM patterns, it was observed that the Al(111) was aligned to the substrate with Al<1l0>//Si<1l0>. Possible mechanisms of the PIB epitaxial growth and a novel structural defect that is unique to this large lattice mismatch system are discussed.

Heteroepitaxial growth and structural analysis of epitaxial α–Fe2O3(1010) on TiO2(001)

2005 ◽  
Vol 20 (5) ◽  
pp. 1250-1256 ◽  
Author(s):  
Joshua R. Williams ◽  
Chongmin Wang ◽  
Scott A. Chambers
Keyword(s):  
Lattice Mismatch ◽  
High Energy ◽  
Unit Cell ◽  
Heteroepitaxial Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Pole Figures ◽  
Large Lattice ◽  
Large Lattice Mismatch

We grew epitaxial α–Fe2O3(1010) on TiO2(001) rutile by oxygen plasma-assisted molecular-beam epitaxy. High-resolution transmission electron microscopy (HRTEM), reflection high-energy electron diffraction (RHEED), and x-ray diffraction pole figures confirm that the film is composed of four different in-plane orientations rotated by 90° relative to one another. For a given Fe2O3 unit cell, the lattice mismatch along the parallel [0001]Fe2O3 and [100]TiO2 directions is nominally +67%. However, due to a 3-fold repetition of the slightly distorted square symmetry of anion positions within the Fe2O3 unit cell, there is a coincidental anion alignment along the [0001]Fe2O3 and [100]TiO2 directions, which results in an effective lattice mismatch of only −0.02% along this direction. The lattice mismatch is nearly 10% in the orthogonal [1120]Fe2O3 and [100]TiO2 directions. The film is highly ordered and well registered to the substrate despite a large lattice mismatch in one direction. The film grows in registry with the substrate along the parallel [0001]Fe2O3 and [100]TiO2 directions and nucleates dislocations along the orthogonal [1120]Fe2O3 [100]TiO2 directions.

High-resolution TEM of thin-film β-SiC interfaces

1986 ◽  
Vol 44 ◽  
pp. 408-409
Author(s):  
S.R. Nutt ◽  
David J. Smith
Keyword(s):  
Thin Films ◽  
Lattice Mismatch ◽  
Detailed Examination ◽  
Cross Sectional ◽  
High Resolution Tem ◽  
Wafer Substrate ◽  
Device Applications ◽  
Large Lattice Mismatch ◽  
Free Films ◽  
Interface Structures

Silicon carbide is a large band gap semiconductor under development for microelectronic device applications involving high temperatures, high frequencies, and high power. Single crystal thin films of high purity β-SiC can be fabricated by epitaxial CVD onto a <100> silicon wafer substrate. Epitaxial growth is achieved by a two-step process in which the surface of the silicon substrate is first converted to SiC by heating in the presence of hydrocarbon vapors, Despite the large lattice mismatch, this process results in an epitaxial film of β-SiC 10nm in thickness, upon which the SiC crystal is then chemically vapor deposited. Relatively thick (20 microns) crack-free films of SiC can thus be fabricated, although significant problems remain, such as lattice constant and thermal expansivity mismatches, and metallization and passivation of the surface. These reasons have provided the motivation for a detailed examination of interface structures in β-SiC thin films using HRTEM imaging of cross-sectional specimens.

The Control of Epitaxial Growth of LiNbO3 Thin Films on R-Cut Sapphire

1991 ◽  
Vol 243 ◽  
Author(s):  
Norifumi Fujimura ◽  
Masami Kakinoki ◽  
Taichiro Ito
Keyword(s):  
Strong Influence ◽  
Lattice Mismatch ◽  
Lithium Concentration ◽  
Epitaxial Films ◽  
Rf Power ◽  
Growth Orientation ◽  
Bonded Materials ◽  
Covalently Bonded ◽  
Large Lattice ◽  
Large Lattice Mismatch

AbstractIt is argued that epitaxial films of ionically-bonded materials are more easily achieved than of covalently bonded materials. Good epitaxy can be achieved despite relatively large lattice mismatch with respect to the substrate. However, the strong influence of interfacial energy can result in difficulty in controlling the orientation of epitaxial films.The crystallographic orientation of ionically-bonded LiNbO3 films was therefore studied. Growth orientation could be controlled by paying attention to the bonding between octahedra in the structure, and to the formation of the octahedra containing lithium and niobium ions. Lithium concentration could be increased by increasing the rf power, 02 partial pressure and total gas pressure, and decreasing the substrate temperature during deposition.The orientation of the film changed from (012) to (100) via (110) by increasing the Li concentration in the film. The (012) and (100) films were epitaxial with respect to the substrate. In particular, the (100) films were of exce lent quality, being single crystalline with smooth surfaces.

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