Epitaxial Relationships and Electrical Properties of SrTiO3 Films on Various Thin -Fluoride/Si Structures

1994 ◽  
Vol 341 ◽  
Author(s):  
B. K. Moon ◽  
H. Ishiwara

AbstractCrystalline strontium titanate (SrTiO3:STO) films were grown on Si(111) and Si(100) substrates using thin SrF2 and CaF2 buffer layers by two-step growth method. In all cases, fluoride buffer layers were effective in growing STO films on Si substrates, which is probably due to that fluoride buffer layers have excellent crystallinity and they can prevent formation of amorphous SiO2 layers on Si substrates at the initial stage of the STO deposition. It was found from X-ray diffraction and pole-figure measurements that (110)-oriented STO crystallites with three different positions to the substrate were grown on Si(111) substrates for both SrF2 and CaF2 buffer layers. In constrast, (100)-oriented STO films with 12-fold symmetry were grown on a SrF2/Si(100), and mixed (110)- and (100)-oriented STO crystallites were grown on a CaF2/Si(100) structure. It was concluded from these results that better crystallinity of STO films can be obtained on the SrF2 buffer layer in case of Si(111) and on the CaF2 buffer layer in case of Si(100). It was also found from I-V and C-V analyses that the STO films have good insulating and dielectric characteristics. For a SrTiO3 film on SrF2/Si(111) structure, the best values of breakdown field (at l.μA/cm2), resistivity (at IMV/cm) and dielectric constant were 2.3MV/cm, 8.2 × 1012 Ωcm and 72, respectively.

1995 ◽  
Vol 399 ◽  
Author(s):  
A. Gray ◽  
N.K. Dhar ◽  
W. Clark ◽  
P. Charlton ◽  
J.H. Dinan ◽  
...  

ABSTRACTX-ray diffraction spectra of CdTe epilayers grown with and without ZnTe buffer layers on <211> Si substrates by molecular beam epitaxy consist of 422 and 331 reflections. We interpret these as evidence for the existence of twins within the volume of a <211> oriented epilayer and show that twin volume is dependent on the ZnTe buffer layer and substrate misorientation.


2007 ◽  
Vol 1040 ◽  
Author(s):  
Hiroaki Yokoo ◽  
Naoki Wakiya ◽  
Naonori Sakamoto ◽  
Takato Nakamura ◽  
Hisao Suzuki

AbstractWe have grown indium nitride (InN) films using In buffer layer on an a-plane sapphire substrate under atmospheric pressure by halide CVD (AP-HCVD). Growth was carried out by two steps: deposition In buffer layer at 900 °C and subsequent growth of InN layer at 650 °C. In order to compare, we also grown InN films on an a-plane sapphire. The InN films are investigated on crystal quality, surface morphology and electrical property using high-resolution X-ray diffraction (HR-XRD), X-ray pole figure, scanning electron microscope (SEM), Hall measurement. The results show that the crystal quality, surface morphology and electrical property of InN films are improved by using In buffer layer.


1992 ◽  
Vol 242 ◽  
Author(s):  
T. D. Moustakas ◽  
R. J. Molnar ◽  
T. Lei ◽  
G. Menon ◽  
C. R. Eddy

ABSTRACTGaN films were grown on c-plane (0001), a-plane (1120) and r-plane (1102) sapphire substrates by the ECR-assisted MBE method. The films were grown using a two-step growth process, in which a GaN buffer is grown first at relatively low temperatures and the rest of the film is grown at higher temperatures. RHEED studies indicate that this growth method promotes lateral growth and leads to films with smooth surface morphology. The epitaxial relationship to the substrate, the crystalline quality and the surface morphology were investigated by RHEED, X-ray diffraction and SEM studies.


2002 ◽  
Vol 742 ◽  
Author(s):  
Hiroyuki Nagasawa ◽  
Kuniaki Yagi ◽  
Takamitsu Kawahara ◽  
Naoki Hatta

ABSTRACTA novel technique to reduce planar defects in 3C-SiC is to grow it on “undulant-Si” substrates, on which the surface forms countered slopes oriented in the [110] and [110] directions. In the initial stage of 3C-SiC growth, step flow epitaxy occurs on each slope of the substrate, reducing the anti-phase boundaries. Then, the stacking faults in the (111) and (111) planes are gradually annihilated by combining with counter-stacking faults, while those parallel to (111) and (111) vanish. The freestanding 3C-SiC exhibits anisotropy in its electrical properties. The origin of the anisotropy in electrical properties is discussed by referring to the results of X-ray diffraction study.


2008 ◽  
Vol 368-372 ◽  
pp. 1358-1361 ◽  
Author(s):  
Xiao Yan Fu ◽  
Hiroshi Yamada ◽  
Chao Nan Xu

The influence of pre-deposition of homo-buffer layers on film quality is studied for SrAl2O4:Eu2+ (SAO) crystalline film prepared by RF magnetron method. This preparation technique is necessary to prepare high quality films suitable for the development of SAO devices. Crystallinity and surface morphology were characterized by X-ray diffraction and scanning electron microscopy. After introducing a homo-buffer layer, not only the crystalline but also the surface morphology and adhesion of the film were obviously improved. These results imply that the buffer layer relaxes the strain due to the lattice mismatch between SAO and quartz glass, which improved the crystalline and adhesion of the film.


1995 ◽  
Vol 395 ◽  
Author(s):  
J.C. Ramer ◽  
K. Zheng ◽  
C.F. Kranenberg ◽  
M. Banas ◽  
S.D Hersee

ABSTRACTUsing atomic force microscopy (AFM) and X-ray diffraction (XRD) we have determined that on [0001] oriented sapphire, the GaN buffer layer shows a degree of crystallinity that is dependent on growth rate. Annealing studies show evolution of the crystallinity and the emergence of a preferred orientation. Also, substrate orientation is found to influence the buffer layer crystallinity. Based on this work and previous results, we propose that the GaN buffer layer growth can be described by the Stranski-Krastanov growth process.


2000 ◽  
Vol 15 (9) ◽  
pp. 1962-1971 ◽  
Author(s):  
R. E. Koritala ◽  
M. T. Lanagan ◽  
N. Chen ◽  
G. R. Bai ◽  
Y. Huang ◽  
...  

Polycrystalline Pb(ZrxTi1−x)O3 thin films with x = 0.6 and 1.0 were deposited at low temperatures (450–525 °C) on (111)Pt/Ti/SiO2/Si substrates by metalorganic chemical vapor deposition. The films were characterized by x-ray diffraction, electron microscopy, and electrical measurements. The texture of the films could be improved by using one of two template layers: PbTiO3 or TiO2. Electrical properties, including dielectric constants, loss tangents, polarization, coercive field, and breakdown field, were also examined. PbZrO3 films on Pt/Ti/SiO2/Si with a pseudocubic (110) orientation exhibited an electric-field-induced transformation from the antiferroelectric phase to the ferroelectric phase. The effect of varying processing conditions on the microstructure and electrical properties of the films is discussed.


1987 ◽  
Vol 91 ◽  
Author(s):  
Tetsuo Soga ◽  
Toru Imori ◽  
Masayoshi Umeno

ABSTRACTThe stress and strain of GaAs on Si grown by using strained superlattice intermediate layers and a two-step growth method are characterized by the photoluminescence, X-ray diffraction and the curvature radius. The strain of GaAs grown using strained superlattice intermediate layers is smaller than that grown by the two-step growth method.


1993 ◽  
Vol 302 ◽  
Author(s):  
T. J. de Lyon ◽  
S. M. Johnson ◽  
C. A. Cockrum ◽  
O. K. Wu ◽  
J. A. Roth

ABSTRACTEpitaxial films of ZnTe(100) and CdZnTe(100)/ZnTe(100) have been deposited by molecular-beam epitaxy onto Si(100) substrates misoriented from 0-8 degrees towards the [011] direction. The films were characterized with x ray diffraction, photoluminescence spectroscopy, optical microscopy, and stylus profilometry. Through use of ZnTe buffer layers, single crystal CdZnTe(100) films have been demonstrated on both 4° and 8° misoriented Si with structural quality comparable to that obtained with GaAs/Si composite substrates. X ray rocking curves for ZnTe(400) with FWHM less than 300 arcseconds and for CdZnTe(400) with FWHM less than 160 arcseconds have been obtained for as-grown films. The observed surface morphologies are superior to those obtained on GaAs/Si composite substrates. HgCdTe(100) films with x ray FWHM as low as 55 arcseconds and average etch pit densities of 5 x 106 cm−2 have been deposited by liquid phase epitaxy on these MBE CdZnTe/ZnTe/Si substrates.


2001 ◽  
Vol 692 ◽  
Author(s):  
Kazuto Koike ◽  
Takanori Tanite ◽  
Shigehiko Sasa ◽  
Masataka Inoue ◽  
Mitsuaki Yano

AbstractThis report describes the growth of single-crystalline ZnO films on Si (111) substrates by plasma-assisted molecular-beam epitaxy. X-ray diffraction measurement shows that c-axis oriented ZnO films are easily grown on Si (111) substrates. However, in-plane random rotational domains are included in the ZnO films due to the inevitable oxidation of substrate surface at the initial stage of ZnO growth. By employing a thin CaF2 buffer layer between the ZnO films and Si substrates, we have succeeded in suppressing the generation of rotational domains and in obtaining an intense ultraviolet photoluminescence even at room temperature. These results indicate that the use of CaF2 buffer layer is promising for the growth of device-quality ZnO films on Si (111) substrates.


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