Si1-xGex Critical Thickness for Surface Wave Generation During UHV-CVD Growth at 525°C

1995 ◽  
Vol 399 ◽  
Author(s):  
H. Lafontaine ◽  
D.C. Houghton ◽  
B. Bahierathan ◽  
D.D. Perovic ◽  
J.-M. Baribeau
Keyword(s):  
Electron Microscopy ◽  
Surface Waves ◽  
Critical Thickness ◽  
Critical Value ◽  
Misfit Dislocations ◽  
Cross Sectional ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Cvd Growth

ABSTRACTSeveral Si1-xGex/Si heterostructures were grown at 525°C using a commercially available UHV-CVD reactor. Layers with a germanium fraction ranging from 0.15 to 0.5 were examined by means of cross-sectional transmission electron microscopy and atomic force microscopy. Surface waves were found in layers with a thickness above a critical value which decreases rapidly as the Ge fraction is increased. Both experimental and modeling results show that surface waves are generated before misfit dislocations for Ge fractions above 0.3.

TEM Studies on the Microstructure of m-Face Grown 4H-SiC by Solution Growth

2020 ◽  
Vol 1004 ◽  
pp. 414-420
Author(s):  
Junro Takahashi ◽  
Kotaro Kawaguchi ◽  
Kazuhiko Kusunoki ◽  
Tomoyuki Ueyama ◽  
Kazuhito Kamei
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solution Growth ◽  
Spiral Growth ◽  
Growth Surface ◽  
Vicinal Surface ◽  
Cross Sectional ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron

We have studied the microstructure of the growth surface of the 4H-SiC grown by the m-face solution growth. Atomic Force Microscopy (AFM) revealed the micro-striped morphology with the asperity of several nm in the band-like morphology region. The cross-sectional Transmission Electron Microscopy (XTEM) showed that the growth surface consisted of a bunch of nanofacets and vicinal surface. This peculiar morphology is totally different from that of conventional spiral growth on c-face, which can be closely related with the growth mechanism of the m-face solution growth.

Nanomechanical Properties and Nanostructure of CMG and CMP Machined Si Substrates

2008 ◽  
Vol 381-382 ◽  
pp. 525-528 ◽  
Author(s):  
B.L. Wang ◽  
Han Huang ◽  
Jin Zou ◽  
Li Bo Zhou
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Substrate Surface ◽  
Transmission Electron Microscopy Analysis ◽  
Cross Sectional ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Transmission Electron ◽  
Electron Microscopy Analysis

Silicon (100) substrates machined by chemo-mechanical-grinding (CMG) and chemicalmechanical- polishing (CMP) were investigated using atomic force microscopy, cross-sectional transmission electron microscopy and nanoindentation. It was found that the substrate surface after CMG was slightly better than machined by CMP in terms of roughness. The transmission electron microscopy analysis showed that the CMG-generated subsurface was defect-free, but the CMP specimen had a crystalline layer of about 4 nm in thickness on the top of the silicon lattice as evidenced by the extra diffraction spots. Nanoindentation results indicated that there exists a slight difference in mechanical properties between the CMG and CMP machined substrates.

MORPHOLOGICAL CONTROL OF GaN BUFFER LAYERS GROWN BY MOLECULAR BEAM EPITAXY ON 6H–SiC(0001)

2000 ◽  
Vol 07 (05n06) ◽  
pp. 565-570 ◽  
Author(s):  
CHANGWU HU ◽  
DAVID J. SMITH ◽  
R. B. DOAK ◽  
I. S. T. TSONG
Keyword(s):  
Electron Microscopy ◽  
Substrate Surface ◽  
Supersonic Jet ◽  
Flux Ratio ◽  
Buffer Layers ◽  
Cross Sectional ◽  
Growth Ratio ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron

The growth of GaN buffer layers of thickness 10–25 nm directly on 6H–SiC (0001) substrates was studied using low energy electron microscopy, atomic force microscopy and cross-sectional transmission electron microscopy. The Ga flux was supplied by an evaporative source, while the NH3 flux came from a seeded beam supersonic jet source. By monitoring the growth in situ and by suitably adjusting the Ga/NH 3 flux ratio, smooth basal-plane-oriented GaN layers were grown on hydrogen-etched SiC substrates at temperatures in the range of 600–700°C. The growth proceeds via nucleation of small flat islands at the step edges of the 6H–SiC (0001) substrate surface. The islands increase in size with a lateral-to-vertical growth ratio of ~10 and eventually coalesce into a quasicontinuous layer. A highly defective substrate surface was found to be detrimental to the growth of flat buffer layers.

Structural Characterization of Prismatic Stacking Faults of Two Types of Carrot Defects in 4H-SiC Epi Wafers

2020 ◽  
Vol 1004 ◽  
pp. 421-426
Author(s):  
Hideki Sako ◽  
Kentaro Ohira ◽  
Kenji Kobayashi ◽  
Toshiyuki Isshiki
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Stacking Faults ◽  
Wafer Surface ◽  
Cross Sectional ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
The Difference

Two types of carrot defects with and without a shallow pit were found by mirror projection electron microscopy (MPJ) inspection in 4H-SiC epi wafer. Surface morphology and cross-sectional structure of prismatic stacking faults (PSFs) were investigated using MPJ and atomic force microscopy (AFM), transmission electron microscopy (TEM) and high-resolution scanning transmission electron microscopy (STEM). The depths of the surface grooves due to the PSFs, the stacking sequences around the PSFs and the structure of the Frank-type stacking faults which were connected to the PSFs were different. We discuss the difference between the two types of carrot defects.

Compliance at the GaSb/GaP Interface by Misfit Dislocations Array

2011 ◽  
Vol 324 ◽  
pp. 85-88
Author(s):  
Salim El Kazzi ◽  
Ludovic Desplanque ◽  
Christophe Coinon ◽  
Yi Wang ◽  
Pierrre Ruterana ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Energy ◽  
Misfit Dislocations ◽  
Initial Growth ◽  
Electron Diffraction Analysis ◽  
High Energy Electron ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron

We study the initial growth of 10 monolayers (MLs) of GaSb on a (001) GaP substrate. Transmission electron microscopy and reflection high energy electron diffraction analysis show that an Sb-rich GaP surface promotes the formation of a 90° misfit dislocation array at the epi-substrate interface. Using atomic force microscopy, we investigate the influence of the growth temperature and the growth rate on the formation and the shape of GaSb islands.

Investigation of the Shape of InGaAs/GaAs Quantum Dots

2002 ◽  
Vol 737 ◽  
Author(s):  
Susan Y. Lehman ◽  
Alexana Roshko ◽  
Richard P. Mirin ◽  
John E. Bonevich
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Quantum Dots ◽  
Molecular Beam ◽  
Length Scale ◽  
Cross Sectional ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Three Samples

ABSTRACTThree samples of self-assembled In0.44Ga0.56As quantum dots (QDs) grown on (001) GaAs by molecular beam epitaxy (MBE) were studied using atomic force microscopy (AFM) and high-resolution transmission electron microscopy (TEM) in order to characterize the height, faceting, and densities of the QDs. The cross-sectional TEM images show both pyramidal dots and dots with multiple side facets. Multiple faceting has been observed only in dots more than 8.5 nm in height and allows increased dot volume without a substantial increase in base area. Addition of a GaAs capping layer is found to increase the diameter of the QDs from roughly 40 nm to as much as 200 nm. The areal QD density is found to vary up to 50 % over the central 2 cm x 2 cm section of wafer and by as much as 23 % on a length scale of micrometers.

scholarly journals Pinholes, Dislocations and Strain Relaxation in InGaN

1998 ◽  
Vol 3 ◽  
Author(s):  
B. Jahnen ◽  
M. Albrecht ◽  
W. Dorsch ◽  
S. Christiansen ◽  
H. P. Strunk ◽  
...  
Keyword(s):  
Critical Thickness ◽  
Strain Relaxation ◽  
Threading Dislocations ◽  
Misfit Dislocations ◽  
Slip Systems ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Wurtzite Lattice ◽  
Means Of Transmission

We analyse by means of transmission electron microscopy (TEM) and atomic force microscopy (AFM) the strain relaxation mechanisms in InGaN layers on GaN as dependent on the In content. At the experimentally given thickness of 100 nm, the layers remain coherently strained, up to an In concentration of 14 %. We show that part of the strain is reduced elastically by formation of hexagonally facetted pinholes. First misfit dislocations are observed to form at pinholes that reach the InGaN/GaN interface. We discuss these results in the framework of the Matthews-Blakeslee model for the critical thickness considering the Peierls force for glide of threading dislocations in the different slip systems of the wurtzite lattice.

KINETICS, MICROSTRUCTURE AND STRAIN IN GaN THIN FILMS GROWN VIA PENDEO-EPITAXY

2004 ◽  
Vol 14 (01) ◽  
pp. 21-37
Author(s):  
A. M. ROSKOWSKI ◽  
E. A. PREBLE ◽  
S. EINFELDT ◽  
P. M. MIRAGLIA ◽  
J. SCHUCK ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Growth Conditions ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Force Microscopy ◽  
Microelectronic Devices ◽  
Atomic Force ◽  
Transmission Electron ◽  
Thermal Stability Of

Maskless pendeo-epitaxy involves the lateral and vertical growth of cantilevered "wings" of material from the sidewalls of unmasked etched forms. Gallium Nitride films grown at 1020°C via metalorganic vapor phase epitaxy on GaN / AlN /6 H - SiC (0001) substrates previously etched to form [Formula: see text]-oriented stripes exhibited similar vertical [0001] and lateral [Formula: see text] growth rates, as shown by cross-sectional scanning electron microscopy. Increasing the temperature increased the growth rate in the latter direction due to the higher thermal stability of the [Formula: see text] surface. The [Formula: see text] surface was atomically smooth under all growth conditions with a root mean square (RMS)=0.17 nm. High resolution X-ray diffraction and atomic force microscopy of the pendeo-epitaxial films confirmed transmission electron microscopy results regarding the significant reduction in dislocation density in the wings. This result is important for the properties of both optoelectronic and microelectronic devices fabricated in III-Nitride structures. Measurement of strain indicated that the wing material is crystallographically relaxed as evidenced by the increase in the c-axis lattice parameter and the upward shift of the E2 Raman line frequency. A strong D°X peak at 3.466 eV was also measured in the wing material. However, tilting of the wings of ≤0.15° occurred due to the tensile stresses in the stripes induced by the mismatch in the coefficients of thermal expansion between the GaN and the underlying substrate.

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