TEM Analysis of Threading Dislocations in ELO-GaN Grown with Controlled Facet Planes

2000 ◽  
Vol 639 ◽  
Author(s):  
Noriyuki Kuwano ◽  
Kayo Horibuchi ◽  
Hideto Miyake ◽  
Kazumasa Hiramatsu
Keyword(s):  
Growth Rate ◽  
Ambient Pressure ◽  
Epitaxial Lateral Overgrowth ◽  
Threading Dislocations ◽  
Tem Analysis ◽  
Cross Sectional ◽  
Lateral Overgrowth ◽  
Transmission Electron ◽  
Facet Plane ◽  
Reactor Pressure

ABSTRACTCross sectional transmission electron microscope (TEM) observation has been performed for specimens of ELO-GaN (ELO: epitaxial-lateral-overgrowth) in order to analyze the behavior of dislocations, with special reference to the effect of facet plane orientation and the size of mask. An ELO-GaN layer was grown overlying on a thick GaN layer with a patterned mask by MOVPE with a carrier gas of hydrogen (H2) under a low-ambient pressure. The growth temperature and the reactor-pressure were controlled in a two-step way during the growth of ELO-GaN layer in order to change the dominant facet-planes and the aspect ratio in growth rate. The experimental results revealed that (a+c)-type threading dislocations (TDs) show a 90-degree-bending in the specimen with slanting facets (2 1 1 2), but not in those with vertical ones (2110). a-type TDs run upward without bending irrespective of the orientation of the facet planes. Dislocations lying on (0001) planes, or horizontal dislocations (HDs), have been generated in the specimens with wide mask-terraces. It is thought that the formation of HDs relieved stresses in the ELO-GaN and then suppressed the bending of a-type TDs. In the specimens with narrow terraces, the both type TDs penetrate upward without bending and few HDs are generated. The behavior of dislocations is attributable to the fact that the small size of terrace generates small stresses and promotes a fast meeting of wings of ELO-GaN.

TEM Sample Preparation Tricks for Advanced DRAMs

2015 ◽  
Author(s):  
Ching Shan Sung ◽  
Hsiu Ting Lee ◽  
Jian Shing Luo
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Sample Preparation ◽  
Integrated Circuit ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Tem Analysis ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Characterization Of Materials

Abstract Transmission electron microscopy (TEM) plays an important role in the structural analysis and characterization of materials for process evaluation and failure analysis in the integrated circuit (IC) industry as device shrinkage continues. It is well known that a high quality TEM sample is one of the keys which enables to facilitate successful TEM analysis. This paper demonstrates a few examples to show the tricks on positioning, protection deposition, sample dicing, and focused ion beam milling of the TEM sample preparation for advanced DRAMs. The micro-structures of the devices and samples architectures were observed by using cross sectional transmission electron microscopy, scanning electron microscopy, and optical microscopy. Following these tricks can help readers to prepare TEM samples with higher quality and efficiency.

Photo Modified Growth of GaAs by Chemical Beam Epitaxy

1998 ◽  
Vol 510 ◽  
Author(s):  
R. Jothilingam ◽  
T. Farrell ◽  
T.B. Joyce ◽  
P.J. Goodhew
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Growth Rate ◽  
Electrical Power ◽  
Xenon Lamp ◽  
Chemical Beam Epitaxy ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Substrate Temperatures ◽  
Laser Reflectometry

AbstractWe report the photo modified growth of GaAs by chemical beam epitaxy at substrate temperatures in the range 335 to 670°C using triethygallium (TEG) and arsine. A mercury-xenon lamp (electrical power 200 W) provided the irradiation for the photoassisted growth. The growth was monitored in real time by laser reflectometry (LR) using a 670 nm semiconductor laser, and the optically determined growth rate agreed with that obtained from the layer thickness measured by cross sectional transmission electron microscopy. The observed photo-enhancement of the growth rate at low substrate temperatures and inhibition at high substrate temperatures is thermal in origin, consistent with raising the substrate temperature by 10±3°C. Cross sectional transmission electron microscopy showed that the photoassisted layers are essentially free from dislocations

Single Crystal Silicon Carbide On Silicon Using A Supersonic Gas Jet Of Methylsilane

1997 ◽  
Vol 483 ◽  
Author(s):  
S. A. Ustin ◽  
C. Long ◽  
L. Lauhon ◽  
W. Ho
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Single Crystal Silicon ◽  
Maximum Growth ◽  
X Ray Diffraction ◽  
Crystal Silicon ◽  
Cross Sectional ◽  
Supersonic Molecular Beam ◽  
Transmission Electron

AbstractCubic SiC films have been grown on Si(001) and Si(111) substrates at temperatures between 600 °C and 900 °C with a single supersonic molecular beam source. Methylsilane (H3SiCH3) was used as the sole precursor with hydrogen and nitrogen as seeding gases. Optical reflectance was used to monitor in situ growth rate and macroscopic roughness. The growth rate of SiC was found to depend strongly on substrate orientation, methylsilane kinetic energy, and growth temperature. Growth rates were 1.5 to 2 times greater on Si(111) than on Si(001). The maximum growth rates achieved were 0.63 μm/hr on Si(111) and 0.375μm/hr on Si(001). Transmission electron diffraction (TED) and x-ray diffraction (XRD) were used for structural characterization. In-plane azimuthal (ø-) scans show that films on Si(001) have the correct 4-fold symmetry and that films on Si(111) have a 6-fold symmetry. The 6-fold symmetry indicates that stacking has occurred in two different sequences and double positioning boundaries have been formed. The minimum rocking curve width for SiC on Si(001) and Si(111) is 1.2°. Fourier Transform Infrared (FTIR) absorption was performed to discern the chemical bonding. Cross Sectional Transmission Electron Microscopy (XTEM) was used to image the SiC/Si interface.

Epitaxial Lateral Overgrowth of GaN on SiC and Sapphire Substrates

1998 ◽  
Vol 537 ◽  
Author(s):  
Zhonghai Yu ◽  
M.A.L. Johnson ◽  
J.D. Brown ◽  
N.A. El-Masry ◽  
J. F. Muth ◽  
...  
Keyword(s):  
Single Crystal ◽  
Epitaxial Lateral Overgrowth ◽  
Threading Dislocations ◽  
Growth Processes ◽  
Mbe Growth ◽  
Sapphire Substrates ◽  
Lateral Overgrowth ◽  
Movpe Growth ◽  
Gan Film ◽  
Growth Experiments

AbstractThe epitaxial lateral overgrowth (ELO) process for GaN has been studied using SiC and sapphire substrates. Both MBE and MOVPE growth processes were employed in the study. The use of SiO2 versus SiNx insulator stripes was investigated using window/stripe widths ranging from 2 μm/4 μm to 3 μm/15 μm. GaN film depositions were completed at temperatures ranging from 800°C to 1120°C. Characterization experiments included RHEED, TEM, SEM and cathodolumenescence studies. The MBE growth experiments produced polycrystalline GaN over the insulator stripes even at deposition temperatures as high as 990°C. In contrast, MOVPE growth produced single-crystal GaN stripes with no observable threading dislocations.

Nanoindentation in Tin/Nbn Multilayers and Thin Films Examined Using Transmission Electron Microscopy

1999 ◽  
Vol 5 (S2) ◽  
pp. 776-777
Author(s):  
S.J. Lloyd ◽  
J.E. Pitchford ◽  
J.M. Molina-Aldareguia ◽  
Z.H. Barber ◽  
M.G. Blamire ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Deformation Structure ◽  
Tem Analysis ◽  
Repeat Distance ◽  
Cross Sectional ◽  
Thin Coatings ◽  
Transmission Electron ◽  
Salt Structure ◽  
Interesting System

Nanoindentation allows the hardness of thin coatings and synthetic multilayer structures to be measured, since indentation depths can be as little as a few 10s of nm. In combination with the cross-sectional transmission electron microscopy (TEM) analysis described here it is possible to observe the deformation structure under an indent, and potentially to understand deformation mechanisms on a nm scale in a wide variety of materials. Synthetic multilayers are a particularly interesting system to investigate. Variations in hardness with the multilayer compositional repeat distance (A) have been reported for several systems. The highest hardnesses, which are in excess of what a simple “rule of mixtures” would predict, occur in nitride multilayers at A ∼5nm. Here we present some preliminary results showing the deformation structure in both a monolithic NbN film and a TiN/NbN multilayer in which both components have the rQck salt structure with lattice parameters 0.424nm (TiN) and 0.439nm (NbN).

Review of Facet Controlled Epitaxial Lateral Overgrowth (FACELO) of GaN via Low Pressure Vapor Phase Epitaxy

2000 ◽  
Vol 639 ◽  
Author(s):  
Kazumasa Hiramatsu ◽  
Hideto Miyake
Keyword(s):  
Vapor Phase ◽  
Low Pressure ◽  
Growth Conditions ◽  
Vapor Phase Epitaxy ◽  
Epitaxial Lateral Overgrowth ◽  
Propagation Mechanism ◽  
Threading Dislocations ◽  
Facet Structure ◽  
Lateral Overgrowth ◽  
Window Area

ABSTRACTFacet structures of GaN grown by epitaxial lateral overgrowth (ELO) via low pressure-metalorganic vapor phase epitaxy (LP-MOVPE) are controlled by growth conditions such as reactor pressure and growth temperature, where this technique is called FACELO (Facet Controlled ELO). The mechanism of the morphological change is discussed based on stability of the surface atoms. The propagation mechanism of the threading dislocations for the different GaN facet structure is also investigated. The distribution and density of the threading dislocations are observed by the growth pit density (GPD) method. Two typical models employing the FACELO are proposed; in one model, the dislocation concentrates only on the window area and, in the other model, only in the coalescence region in the center of the mask. In the latter model, the dislocation density is dramatically dropped to the order of 105−6 cm−2 with good reproducibility.

Kinetic Modelling Of The Selective Epitaxy Of GaAs On Patterned Substrates By Hvpe. Application to the Conformal Growth Of Low Defect Density GaAs Layers On Silicon

1998 ◽  
Vol 535 ◽  
Author(s):  
E. Gil-Lafon ◽  
J. Napierala ◽  
D. Castelluci ◽  
A. Pimpinelli ◽  
B. Gérard ◽  
...  
Keyword(s):  
Growth Rate ◽  
Defect Density ◽  
Kinetic Modelling ◽  
Selective Growth ◽  
Epitaxial Lateral Overgrowth ◽  
Patterned Substrates ◽  
Lateral Overgrowth ◽  
Dislocation Densities ◽  
Gaas Films ◽  
Sem Analyses

AbstractThe selective growth of GaAs by HVPE was studied on (001), (110), (111)Ga and (111)As, GaAs patterned substrates by varying the I1I/V ratio. A kinetic modelling of the growth was developed, based upon the SEM observations of the growth morphologies as well as on experimental curve synthesis. The growth rate is written as a function of the diffusion fluxes of the adsorbed AsGa and AsGaCI molecules and takes into account the chlorine desorption by H2. 1.5 μm thick GaAs films were then fabricated on Si (001) by a confined epitaxial lateral overgrowth technique. These conformal films exhibit intense and uniform luminescence signals, showing that the dislocation densities of GaAs are lower than 105 cm−2. SEM analyses reveal that conformal growth fronts consist in (110) and (111)As A planes under the III/V ratios (superior to 1) which were tested.

A Novel Approach for The Production of Low Dislocation Relaxed Sige Material.

1993 ◽  
Vol 319 ◽  
Author(s):  
A.R. Powell ◽  
S.S. Iyer ◽  
F.K. Legoues
Keyword(s):  
Sige Layer ◽  
Silicon On Insulator ◽  
Buffer Layers ◽  
Threading Dislocation ◽  
Tem Analysis ◽  
Cross Sectional ◽  
Novel Approach ◽  
Transmission Electron ◽  
Silicon Thickness ◽  
Buffer Structure

AbstractIn this growth process a new strain relief mechanism operates, whereby the SiGe epitaxial layer relaxes without the generation of threading dislocations within the SiGe layer. This is achieved by depositing SiGe on an ultrathin Silicon On Insulator, SOl, substrate with a superficial silicon thickness less than the SiGe layer thickness. Initially, the thin Si layer is put under tension due to an equalization of the strain between the Si and SiGe layers. Thereafter, the strain created in the thin Si layer relaxes by plastic deformation. Since the dislocations are formed and glide in the thin Si layer, no threading dislocation is ever introduced into the upper SiGe material, which appeared dislocation free to the limit of the cross sectional Transmission Electron Microscopy (TEM) analysis. We thus have a method for producing very low dislocation, relaxed SiGe films with the additional benefit of an SO substrate. This buffer structure is significantly less than a micrometer in thickness and offers distinct advantages over the thick SiGe buffer layers presently in use.

Suppression Mechanism of Double Positioning Growth in 3C-SiC(111) Crystal by Using an Off-Axis Si(110) Substrate

2005 ◽  
Vol 483-485 ◽  
pp. 181-184 ◽  
Author(s):  
Mitsutaka Nakamura ◽  
Toshiyuki Isshiki ◽  
Taro Nishiguchi ◽  
Koji Nishio ◽  
Satoru Ohshima ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Growth Rate ◽  
Anisotropic Growth ◽  
Grown Layer ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Cvd Growth ◽  
Suppression Mechanism ◽  
Suppression Process

Hetero-epitaxial CVD growth of 3C-SiC on a Si(110) substrate gives a (111) crystal with low defects density. However, double positioning growth often disturbs growth of a single crystal. The growth on an off-axis Si(110) substrate suppressed propagation of the double positioning defects in the grown layer effectively. Cross-sectional transmission electron microscopy revealed the details of the suppression process on the off-axis substrate. The suppression mechanism and the origin of the defects formation at double positioning boundaries were interpreted by the growth model based on an anisotropic growth rate on (111) plane of 3C-SiC.

TEM Analysis of Planar Defects in InGaAsN and GaAs Grown on Ge (001) by MOVPE

2016 ◽  
Vol 675-676 ◽  
pp. 639-642
Author(s):  
Pornsiri Wanarattikan ◽  
Sakuntam Sanorpim ◽  
Somyod Denchitcharoen ◽  
Visittapong Yordsri ◽  
Chanchana Thanachayanont ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Buffer Layer ◽  
Growth Direction ◽  
Dark Field ◽  
Tem Analysis ◽  
Cross Sectional ◽  
Planar Defects ◽  
Transmission Electron ◽  
Gaas Buffer Layer ◽  
Field Emission Electron Microscopy

InGaAsN on Ge (001) is proposed to be a part of the InGaP(N)/InGaAs/InGaAsN/Ge four-junction solar cell to increase a conversion efficiency over 40%. In this work, InGaAsN lattice-matched film and GaAs buffer layer grown on Ge (001) substrate by metal organic vapor phase epitaxy (MOVPE) were examined by transmission electron microscopy (TEM). Electron diffraction pattern of InGaAsN taken along the [110]-zone axis illustrates single diffracted spots, which represent a layer with a uniformity of alloy composition. Cross-sectional bright field TEM image showed line contrasts generated at the GaAs/Ge interface and propagated to the InGaAsN layer. Dark field TEM images of the same area showed the presence of boundary-like planar defects lying parallel to the growth direction in the InGaAsN film and GaAs buffer layer but not in the Ge substrate. TEM images with the (002) and (00-2) reflections and the four visible {111} planes reflections illustrated planar defects which are expected to attribute to antiphase boundaries (APBs). Moreover, the results observed from atomic force microscopy (AFM) and field emission electron microscopy (FE-SEM) demonstrated the surface morphology of InGaAsN film with submicron-sized domains, which is a characteristic of the APBs.

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