Temperature Dependence of Critical Thickness for Two Dimensional Growth of GexSi1−x on Si Substrate

1991 ◽  
Vol 220 ◽  
Author(s):  
Xun Wang ◽  
G. L. Zhou ◽  
T. C. Zhou ◽  
C. Sheng ◽  
M. R. Yu
Keyword(s):  
Growth Temperature ◽  
Critical Thickness ◽  
Layer Growth ◽  
Layer By Layer ◽  
Two Dimensional ◽  
Si Substrate ◽  
Lower Growth ◽  
Germanium Content ◽  
Si Substrates ◽  
Molecular Beam Epitaxial

ABSTRACTFor obtaining good structural perfection, the molecular beam epitaxial (MBE) growth of GexSi1−x on Si substrate should not only be kept in the pseudomorphic form but also in layer-by-layer growth stage. We found that the two dimensional layer-by-layer growth of GexSi1−x on Si could persist to a certain deposition thickness, beyond that the transition to islanding growth occurs. The transition thickness is significantly dependent on the growth temperature and germanium content, and is always smaller than the critical thickness of pseudomorphic growth. In order to obtain good crystalline quality in growing GexSi1−x superlattices on Si substrates, the thickness of GexSi1−x layers should be controlled below the transition thickness and lower growth temperature is favorable.

CHANNELING ANALYSIS OF Ge EPITAXIAL LAYER ON Si SUBSTRATE AND DOPED Ga ATOMS BY USING RBS AND PIXE METHODS

1992 ◽  
Vol 02 (02) ◽  
pp. 137-149
Author(s):  
KOKI TANAKA ◽  
EIICHI YAGI ◽  
KAZUTO KAWAKAMI ◽  
AKIHIRO ONO
Keyword(s):  
Growth Temperature ◽  
Layer Growth ◽  
Intermediate Annealing ◽  
Si Substrate ◽  
Cross Sectional ◽  
Lattice Disorder ◽  
Si Substrates ◽  
Step Procedure ◽  
20 Nm

On the crystalline quality of Ge layers heteroepitaxially grown on Si substrates by the MBE two-step procedure without the intermediate annealing process, the effect of growth temperature and thickness of the first layer was investigated between 135 and 600 °C, and for 20 and 200 nm, respectively, by means of RBS-channeling and cross-sectional TEM methods. The second layer growth temperature was fixed at 600 °C. It was found that, in reducing the total amount of lattice disorder, the two-step procedure has an advantage over the direct deposition, and 200 nm is more favorable than 20 nm as the first layer thickness. The Ge layer of the best quality was obtained when the first layer of 200nm was grown at 400–500 °C, and subsequently the second layer was grown at 600 °C. The PIXE-channeling method was effectively applied to locate Ga atoms doped in the Ge layer grown by the two-step procedure at 300 and 550 °C. Approximately 40% of Ga atoms were located at substitutional sites and the rest at random sites, probably in the form of precipitates.

Stress Driven Patterning of Epitaxial Films

1993 ◽  
Vol 318 ◽  
Author(s):  
Michael A. Grinfeld
Keyword(s):  
Surface Energy ◽  
Surface Morphology ◽  
Film Thickness ◽  
Critical Thickness ◽  
Epitaxial Films ◽  
Layer By Layer ◽  
Two Dimensional ◽  
Dimensional Lattice ◽  
One Dimensional ◽  
Periodic Spacing

ABSTRACTWe study possible morphologies of epitaxial films atop attractive substrates appearing as a result of competition of misfit stresses, van der Waals forces and surface energy. Corresponding formula for the critical thickness of the dislocation-free Stranski-Krastanov pattern is established for the isotropic deformable films and substrates. If the film thickness exceeds the critical magnitude the layer-by-layer pattern switches to islanding. At the first stage the islands have a shape of striae (i.e. long parallel trenches with periodic spacing). We discuss also i)the circumstances in which surface morphology of the film corresponds to a two-dimensional superlattice of islands rather than a one dimensional lattice of striae and ii)the influence of a buffer inter-layer.

Metal-Organic chemical vapor deposition of BN on sapphire and its heterostructures with 2D and 3D materials

MRS Advances ◽  
2016 ◽  
Vol 1 (32) ◽  
pp. 2273-2283
Author(s):  
Qing Paduano ◽  
Michael Snure
Keyword(s):  
Electron Mobility ◽  
Substrate Surface ◽  
Chemical Vapor ◽  
High Electron Mobility Transistor ◽  
Layer Growth ◽  
Organic Chemical ◽  
Layer By Layer ◽  
High Electron ◽  
Two Dimensional ◽  
Direct Growth

ABSTRACTWe studied MOCVD processing for direct growth of BN on 2” sapphire substrates as a template for heterostructures with two dimensional (2D) and three dimensional (3D) materials. The combined experimental evidence points to three growth modes for BN: self-terminating, 3D random, and layer-by-layer, all of which are dependent on V/III ratio, temperature, pressure, and substrate surface modification via nitridation. At moderate temperature (950-1050°C), BN growth using high V/III ratio is self-terminating, resulting in c-oriented films aligned in-plane with respect to the orientation of the sapphire substrate. BN films grown under low V/III ratios are 3D, randomly oriented, and nano-crystalline. At higher temperature (1100°C), self-terminating growth transitions to a continuous layer-by-layer growth mode. When BN growth is self-terminating, films exhibit atomically smooth surface morphology and highly uniform thickness over a 2” sapphire wafer. Using these BN/sapphire templates we studied the growth of 2D and 2D/3D heterostructures. To study direct growth of 2D on 2D layered material we deposited graphene on BN in a continued process within the same MOCVD system. Furthermore, we explore the growth and nucleation of 3D materials (GaN and AlN) on BN. AlGaN/GaN based high electron mobility transistor (HEMT) structures grown on BN/sapphire exhibited two-dimensional electron gas characteristics at the AlGaN/GaN heterointerface, with room-temperature electron mobility and sheet electron density about 1900cm2/Vs and 1x1013cm-2, respectively.

Rheed Intensity Oscillation During Layer-by-Layer Growth of Bi-Sr-Ca-Cu-O Thin Films

1992 ◽  
Vol 275 ◽  
Author(s):  
K. Yoshikawa ◽  
N. Sasaki
Keyword(s):  
Thin Films ◽  
Buffer Layer ◽  
High Energy ◽  
Layer Growth ◽  
Layer By Layer ◽  
Two Dimensional ◽  
Growth Interruption ◽  
Layer Deposition ◽  
Unit Cells ◽  
Layered Growth

ABSTRACTUsing in-situ reflection high-energy electron diffraction (RHEED), we studied the growth of Bi-Sr-Ca-Cu-O (BSCCO) thin films prepared by reactive evaporation using layer-by-layer deposition. Bi2Sr2CaCu2Ox(2212) tends to be grown three-dimensionally if it is grown directly on (100) SrTiO3, in contrast to Bi2Sr2CuOx(2201) which is easily grown two-dimensionally on SrTiO3. Two-dimensional 2212 growth can be realized, if a buffer layer of 2201 is deposited on (100) SrTiO3 and growth interruption is utilized after SrO layer deposition. A buffer layer of only two 2201 unit cells improved the surface crystallinity of the substrate for the epitaxial growth of 2212. Growth interruption for two minutes after the 2nd SrO layer in the half unit cell is necessary to keep two-dimensional layered growth. The resulting Tc (zero) is 76 K and Jc (at 4.2 K) is 1.5 × 106 (A/cm2) with these epitaxial films.

Energetics of AlN Epitaxial Wetting Layers on SiC (0001)

1996 ◽  
Vol 449 ◽  
Author(s):  
R. Di Felice ◽  
J. E. Northrup ◽  
J. Neugebauer
Keyword(s):  
First Principles ◽  
Three Dimensional ◽  
Layer Growth ◽  
Layer By Layer ◽  
Two Dimensional ◽  
Charge Accumulation ◽  
Wetting Layer ◽  
Interface Charge ◽  
Wetting Layers

ABSTRACTWe present a first-principles characterization of the initial stages of formation of AlN films on c-plane SiC substrates. Studying the competition between two-dimensional films and three-dimensional islands as a function of Al and N abundances, we find that a two-dimensional film can wet the surface in N-rich conditions. Ordered layer-by-layer growth can proceed to some extent on this wetting layer, and is improved by the formation of an atomically mixed interface which eliminates interface charge accumulation. Our results indicate that the stable AlN films grow in the (0001) orientation on the Si-terminated SiC(0001) substrate.

The effect of spacer-layer growth temperature on mobility in a two-dimensional electron gas in PHEMT structures

2006 ◽  
Vol 40 (12) ◽  
pp. 1445-1449 ◽  
Author(s):  
G. B. Galiev ◽  
I. S. Vasil’evskiĭ ◽  
E. A. Klimov ◽  
V. G. Mokerov ◽  
A. A. Cherechukin
Keyword(s):  
Growth Temperature ◽  
Electron Gas ◽  
Layer Growth ◽  
Two Dimensional ◽  
Dimensional Electron ◽  
Two Dimensional Electron Gas ◽  
Spacer Layer ◽  
Dimensional Electron Gas

Low-Temperature, Low-Pressure and Ultrahigh-Rate Growth of Single-Crystalline 3C-SiC on Si Substrate by ULP-CVD Using Organosilane

2010 ◽  
Vol 645-648 ◽  
pp. 147-150 ◽  
Author(s):  
Eiji Saito ◽  
Sergey Filimonov ◽  
Maki Suemitsu
Keyword(s):  
Growth Rate ◽  
Low Temperature ◽  
Temperature Dependence ◽  
Growth Temperature ◽  
High Rate ◽  
Si Substrate ◽  
Single Crystalline ◽  
Step Process ◽  
Si Substrates ◽  
Sic Film

Temperature dependence of the growth rate of 3C-SiC(001) films on Si(001) substrates during ultralow-pressure (ULP: ~10-1 Pa) CVD using monomethylsilane has been investigated in detail by using pyrometric interferometry. A novel behavior, i.e. a sharp division of the growth mode into two regimes depending on the growth temperature, has been found to exist. Based on this finding, we have developed a two-step process, which realizes a low-temperature (900 °C), high-rate growth of single-crystalline 3C-SiC film on Si substrates, whose rate of 3 m/h is extremely high for this ULP process.

Sublimation Growth of 6H-SiC Boule on Various a-Plane Substrates

2000 ◽  
Vol 640 ◽  
Author(s):  
S. Nishino ◽  
T. Nishiguchi ◽  
Y. Masuda ◽  
M. Sasaki ◽  
S. Ohshima
Keyword(s):  
Growth Temperature ◽  
Layer Growth ◽  
Growth Mode ◽  
Layer By Layer ◽  
Step Bunching ◽  
Step Flow ◽  
Cvd Growth ◽  
The Difference ◽  
Step Flow Growth ◽  
Sublimation Growth

ABSTRACTSublimation growth of 6H-SiC was performed on {1100} and {1120} substrates. The difference between the growth on {1100} plane and {1120} plane was observed. {1100} facet was almost flat and there were grooves oriented toward <1120> direction. The step bunching was observed on {1100} plane 5° off-axis. A lot of pits were introduced on {1120} plane of the crystal grown both on {1100} and {1120} substrates. Step flow growth toward <1120> direction created the pits on {1120} plane. It was important to grow crystal by layer by layer growth on {1120} plane. By changing the growth mode from step flow growth to layer by layer growth, pit on the {1120} plane may be reduced as same as CVD growth on {1120} plane. Growth temperature and C/Si ratio should be optimized to keep layer by layer growth.

Silicon-Based Long Wavelength Infrared Detectors Fabricated by Molecular Beam Epitaxy

1991 ◽  
Vol 220 ◽  
Author(s):  
T. L. Lin ◽  
E. W. Jones ◽  
T. George ◽  
A. Ksendzov ◽  
M. L. Huberman
Keyword(s):  
Molecular Beam ◽  
Spectral Response ◽  
Thermionic Emission ◽  
Cutoff Wavelength ◽  
Lower Growth ◽  
Long Wavelength ◽  
Si Substrates ◽  
Molecular Beam Epitaxial ◽  
Boron Doped ◽  
Long Wavelength Infrared

ABSTRACTSiGe/Si heterojunction internal photoemission (HIP) long wavelength infrared (LWIR) detectors have been fabricated by molecular beam epitaxial (MBE) growth of p+ SiGe layers on p-type Si substrates. The SiGe/Si HIP detector offers a tailorable spectral response in the long wavelength infrared regime by varying the SiGe/Si heterojunction barrier. Degenerately doped p+ SiGe layers were grown by MBE using either HBO2 or elemental boron as the dopant source. Improved crystalline quality and lower growth temperatures were achieved for boron-doped SiGe layers as compared with the HBO2-doped layers. The dark current density of the boron-doped HIP detectors was found to be thermionic emission limited and was drastically reduced as compared with that of HBO2-doped HIP detectors. The heterojunction barrier was determined to be 0.066 eV from activation energy analysis of the HIP detectors, corresponding to a 18 μm cutoff wavelength. Photoresponse of the detectors at wavelengths ranging from 2 to 12 μm has been characterized with corresponding quantum efficiencies of 5 – 0.1%.

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