Application of a Desk-Side Double-Axis X-Ray Diffractometer for Very Large Area Epilayer Characterization

1990 ◽  
Vol 208 ◽  
Author(s):  
Neil Loxley ◽  
D. Keith Bowen ◽  
Brian K. Tanner

ABSTRACTA new desk-side double-axis X-ray diffractometer capable of rapid, automatic measurement of lattice mismatch between epitaxial thin films and substrate in a two dimensional grid 150 mm square has been built. The design principles behind the five independent axis systems, specimen loading, and the fail-to-safety X-ray shutter are elucidated, and examples of typical data from substrate material and thin epitaxial films of III-V compounds are presented.

2004 ◽  
Vol 19 (7) ◽  
pp. 2137-2143 ◽  
Author(s):  
Hidenori Hiramatsu ◽  
Kazushige Ueda ◽  
Kouhei Takafuji ◽  
Hiromichi Ohta ◽  
Masahiro Hirano ◽  
...  

Processes and preparation conditions for growing epitaxial thin films of Cu-based, layered oxychalcogenides LnCuOCh (Ln = La, Ce, Pr or Nd; Ch = S1-xSex or Se1-yTey) are reported. Epitaxial thin films on MgO (001) substrates were prepared by a reactive solid-phase epitaxy method. Four-axes high-resolution x-ray diffraction measurements revealed that the crystallographic orientation is (001)[110] LnCuOCh || (001)[110] MgO and the internal stress of the crystalline lattices in the films are relaxed during thermal-annealing process of the reactive solid-phase epitaxy. Furthermore, except for CeCuOS, systematic variations in the lattice constant by chalcogen or lanthanide ion substitutions were observed. These results demonstrated that the reactive solid-phase epitaxy is an efficient technique for fabricating LnCuOCh epitaxial films.


1998 ◽  
Vol 547 ◽  
Author(s):  
David B. Beach ◽  
Jonathan S. Morrell ◽  
Ziling B. Xue ◽  
Eliot D. Specht

AbstractSolution chemistry has been used to synthesize epitaxial films of SrLaGaO4, SrPrGaO4, SrLaAlO4, and SrPrAlO4 on single crystal substrates of [100] SrTiO3 and [100] LaAlO3. Precursor solutions were prepared from metal methoxyethoxides in 2-methoxyethanol. Films were prepared by spin-casting from partially hydrolyzed solutions followed by firing for 20 minutes in air at 850°C. The structure of the films was determined using X-ray diffraction. Theta/2-theta scans and omega scans (rocking curves) indicated that the films were c-axis aligned. Phi scans proved that the films were also aligned in-plane.


2001 ◽  
Vol 700 ◽  
Author(s):  
M. Ohtani ◽  
T. Fukumura ◽  
A. Ohtomo ◽  
T. Kikuchi ◽  
K. Omote ◽  
...  

AbstractWe report on the development of a high throughput x-ray diffractometer that concurrently measures spatially resolved x-ray diffraction (XRD) spectra of epitaxial thin films integrated on a substrate. A convergent x-ray is focused into a stripe on a substrate and the diffracted beam is detected with a two-dimensional x-ray detector, so that the snapshot image represents a mapping of XRD intensity with the axes of the diffraction angle and the position in the sample. High throughput characterization of crystalline structure is carried out for a BaxSr1-xTiO3 composition-spread film on a SrTiO3 substrate. Not only the continuous spread of the composition (x), but also the continuous spread of the growth temperature (T) are given to the film by employing a special heating method. The boundary between the strained lattice and relaxed lattice is visualized by the concurrent XRD as functions of x and T in a high throughput fashion.


2007 ◽  
Vol 14 (04) ◽  
pp. 773-777 ◽  
Author(s):  
J. GAO ◽  
E. G. FU ◽  
X. S. WU

Highly epitaxial thin films of YBa 2 Cu 3 O y (YBCO) have been successfully grown on Si using a double buffer of Eu 2 CuO 4 (ECO)/(yttrium-stabilized zirconia) YSZ. The severe reaction between Si and YBCO is blocked by YSZ, and the crystallinity and superconductivity of the grown YBCO due to the lattice mismatch between YBCO and YSZ are improved by the ECO layer. The grown films were characterized by high-resolution X-ray diffraction, grazing incidence X-ray reflection, scanning electron microscopy (SEM), and Doppler broadened annihilation radiation spectroscopy, respectively. Very clear interfaces were found at YBCO/ECO/YSZ boundaries without any intermediate layer. The YBCO film surface was more smooth and stable. The results obtained indicate that highly epitaxial YBCO thin films can be successfully grown on Si wafers, demonstrating advantages of such a double buffer structure.


Author(s):  
Karren L. More

Beta-SiC is an ideal candidate material for use in semiconductor device applications. Currently, monocrystalline β-SiC thin films are epitaxially grown on {100} Si substrates by chemical vapor deposition (CVD). These films, however, contain a high density of defects such as stacking faults, microtwins, and antiphase boundaries (APBs) as a result of the 20% lattice mismatch across the growth interface and an 8% difference in thermal expansion coefficients between Si and SiC. An ideal substrate material for the growth of β-SiC is α-SiC. Unfortunately, high purity, bulk α-SiC single crystals are very difficult to grow. The major source of SiC suitable for use as a substrate material is the random growth of {0001} 6H α-SiC crystals in an Acheson furnace used to make SiC grit for abrasive applications. To prepare clean, atomically smooth surfaces, the substrates are oxidized at 1473 K in flowing 02 for 1.5 h which removes ∽50 nm of the as-grown surface. The natural {0001} surface can terminate as either a Si (0001) layer or as a C (0001) layer.


1989 ◽  
Vol 160 ◽  
Author(s):  
G. Bai ◽  
M-A. Nicolet ◽  
S.-J. Kim ◽  
R.G. Sobers ◽  
J.W. Lee ◽  
...  

AbstractSingle layers of ~ 0.5µm thick InuGa1-uAs1-vPv (0.52 < u < 0.63 and 0.03 < v < 0.16) were grown epitaxially on InP(100) substrates by liquid phase epitaxy at ~ 630°C. The compositions of the films were chosen to yield a constant banndgap of ~ 0.8 eV (λ = 1.55 µm) at room temperature. The lattice mismatch at room temperature between the epitaxial film and the substrate varies from - 4 × 10-3 to + 4 × 10-3. The strain in the films was characterized in air by x-ray double crystal diffractometry with a controllable heating stage from 23°C to ~ 700°C. All the samples have an almost coherent interfaces from 23°C to about ~ 330°C with the lattice mismatch accomodated mainly by the tetragonal distortion of the epitaxial films. In this temperature range, the x-ray strain in the growth direction increases linearly with temperature at a rate of (2.0 ± 0.4) × 10-6/°C and the strain state of the films is reversible. Once the samples are heated above ~ 300°C, a significant irreversible deterioration of the epitaxial films sets in.


2001 ◽  
Vol 666 ◽  
Author(s):  
Fumiaki Mitsugi ◽  
Tomoaki Ikegami ◽  
Kenji Ebihara ◽  
Jagdish Narayan ◽  
Alexander M. Grishin

ABSTRACTWe prepared colossal magnetoresistive La0.8Sr0.2MnO3 thin films on the MgO, SrTiO3 and LaAlO3 single crystal substrates using KrF excimer pulsed laser ablation technique. The structural and electrical properties of the La0.8Sr0.2MnO3 thin films which were strained by the lattice mismatch are reported. The in-plane lattice mismatch between the La0.8Sr0.2MnO3 and MgO, SrTiO3 and LaAlO3 substrates are -7.8 %, -0.5 % and +2.3 %, respectively. The X-ray diffraction spectra of the films exhibited c-axis orientation. In the case of the La0.8Sr0.2MnO3 / LaAlO3 thin films with thickness over 100 nm, the divided (00l) peaks were observed. The surface morphology and transport property of the strongly stressed La0.8Sr0.2MnO3 / LaAlO3 were different from those of La0.8Sr0.2MnO3 / MgO and La0.8Sr0.2MnO3 / SrTiO3thin films.


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