Very Thin 2D GaAs Films on Si During the Early Stages of Growth by MBE

1989 ◽  
Vol 159 ◽  
Author(s):  
D.B. Fenner ◽  
D.K. Biegelsen ◽  
B.S. Krusor ◽  
F.A. Ponce ◽  
J.C. Tramontana
Keyword(s):  
Electron Spectroscopy ◽  
Molecular Beam ◽  
Flux Ratio ◽  
Cross Sectional ◽  
Stages Of Growth ◽  
Transmission Electron ◽  
Gaas Films ◽  
Lattice Images ◽  
Graded Thickness

ABSTRACTGaAs samples deposited on Si by molecular beam epitaxy (MBE) with a graded thickness of 0–3 nm initially show the presence of a metastable two dimensional (2D) layer containing Ga and As. In the thicker regions of the wedge samples, islands (3D topography) form in the presence of the 2D sea, i.e., Stranski – Krastanov growth. Compositional profiles of these wedges were made with in situ Auger electron spectroscopy (AES) which has allowed the identification of at least four regimes of growth. Lattice images from cross – sectional transmission electron microscopy (XTEM) are consistent with the AES profiles. Substrate temperature during deposition of the films has a strong effect on film topography, as does the beam – flux ratio on film stoichiometry.

Structural Studies of Nucleation and the Initial Stages of Growth of Epitaxial Gaas on Si(100) Substrates

1986 ◽  
Vol 82 ◽  
Author(s):  
R. Hull ◽  
A. Fischer-Colbrie ◽  
S.J. Rosner ◽  
S.M. Koch ◽  
J.S. Harris
Keyword(s):  
Molecular Beam ◽  
Gaas Layer ◽  
Island Size ◽  
Epitaxial Gaas ◽  
Stages Of Growth ◽  
Transmission Electron ◽  
Initial Nucleation ◽  
Gaas Films ◽  
Secondary Defect ◽  
Island Coalescence

ABSTRACTNucleation and growth of GaAs fIlms deposited by Molecular Beam Epitaxy upon Si(l00) substrates are studied by transmission electron microscopy. The initial nucleation of GaAs consists of approximately hemispherical islands associated with steps upon the substratesurface and coherently strained to the substrate lattice. As the island size increases, crystalline defects relax the strain between epilayer and substrate. Island coalescence is a secondary defect generation mechanism. Subsequent growth of the epitaxial GaAs layer reveals a progressive deterioration of the GaAs/Si interface planarity and the growth and eventual dissolution of amorphous or misoriented crystalline regions at the GaAs/Si interface.

Molecular Beam Epitaxical Growth of AlxGa1-xAs on non- Planar Patterned GaAs (100)

1989 ◽  
Vol 145 ◽  
Author(s):  
S. Guha ◽  
A. Madhukar ◽  
K. Kaviani ◽  
Li Chen ◽  
R. Kuchibhotla ◽  
...  
Keyword(s):  
Migration Rate ◽  
Molecular Beam ◽  
Growth Front ◽  
In Situ Growth ◽  
Cross Sectional ◽  
Mbe Growth ◽  
Quantum Well Structures ◽  
Transmission Electron ◽  
Front Profile

AbstractWe have examined some aspects of inter-facet migration during molecular beam epitaxical(MBE) growth of AlxGal-xAs on patterned GaAs (100) substrates. Scanning and cross-sectional transmission electron microscopy are employed to examine the evolution of the growth front profile. We observe significant inter facet migration from (3111/1411) facets which originate from the terrace edges to the flat terrace region. The migration length of cations on these facets is at least 0.9 μm for GaAs growth while for A10.5Ga0.5As it is less than 0.3 μm. We also observe a decreasing inter- facet migration rate with increasing growth. This interfacet migration is exploited for in situ, growth kinetics controlled, creation of laterally confined quantum well structures on the top terrace region and photoluminescence results for these structures are presented.

An Electron Microscopic Characterization of Mbe-Grown ZnSe/CaAs and ZnSe/Ge Heterointerfaces

1990 ◽  
Vol 198 ◽  
Author(s):  
S.B. Sant ◽  
R.W. Smith ◽  
G.C. Weatherly
Keyword(s):  
Molecular Beam ◽  
Nucleation And Growth ◽  
Epitaxial Films ◽  
Defect Characterization ◽  
Initial Growth ◽  
Electron Microscopic ◽  
Cross Sectional ◽  
Transmission Electron

ABSTRACTMolecular beam epitaxy (MBE) grown ZnSe/GaAs and ZnSe/Ge heterointerfaces have been studied by transmission electron microscopy (TEM). Defect characterization of cross-sectional and planar specimens showed that ZnSe epitaxial films contain numerous twins that predominantly arise at the interface. Planar specimens of ZnSe/Ge were in-situ TEM annealed, for 5.5 hours at 873K. The twins are thermally very stable which would indicate that they arise during the growth process. The occurrence of these twins in the ZnSe film is explained by nucleation and growth of normal and twinned nuclei. Some of the ZnSe films grown on (10O)Ge substrates have low-angle boundaries indicating that the initial growth of the film is by the formation of islands.

Controlled Growth of GaAs/AlAs(111)B Superlattices

1992 ◽  
Vol 263 ◽  
Author(s):  
J.E. Angelo ◽  
J.W. Hoehn ◽  
A.M. Dabiran ◽  
P.I. Cohen ◽  
W.W. Gerberich
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Temperature ◽  
Defect Structure ◽  
Molecular Beam ◽  
Substantial Reduction ◽  
Flux Ratio ◽  
Cross Sectional ◽  
Temperature Growth ◽  
Transmission Electron

ABSTRACTIn this study, transmission electron microscopy (TEM) was used to investigate the growthconditions which produce the highest quality GaAs(111)B films by molecular beam epitaxy (MBE). Low-temperature growth using both As4 and arsine as an As2 source produced highly twinned structures, although the use of As4 provided for a smoother surface and slightly different defect structure. Two distinct twin boundaries, (112)A and (112)B, were identified by cross-sectional transmission electron microscopy (XTEM). The (112)A defect could be over-grown by a subsequent high temperature growth but the roughness associated with the (112)B defects only increased with further growth. High temperature growth of GaAs and AlAs films, while maintaining the GaAs(11)surface reconstruction, resulted in substantial reduction in the number of twins boundaries. We also found that GaAs(111)B layer quality and surface morphology can be further improved by a high temperature growth with low arsenic to Ga flux ratio of I to 1.5 ona slightly misoriented substrate.

Near-Surface Aggregation of Sn In Heavily Sn-Doped GaAs Films Grown By Molecular Beam Epitaxy

1985 ◽  
Vol 43 ◽  
pp. 368-369
Author(s):  
S. H. Chen
Keyword(s):  
Molecular Beam Epitaxy ◽  
Cross Section ◽  
Electron Spectroscopy ◽  
Molecular Beam ◽  
Surface Segregation ◽  
Secondary Ion Mass Spectrometry ◽  
Specimen Preparation ◽  
Near Surface ◽  
Gaas Films ◽  
Secondary Ion

Sn has been used extensively as an n-type dopant in GaAs grown by molecular-beam epitaxy (MBE). The surface accumulation of Sn during the growth of Sn-doped GaAs has been observed by several investigators. It is still not clear whether the accumulation of Sn is a kinetically hindered process, as proposed first by Wood and Joyce, or surface segregation due to thermodynamic factors. The proposed donor-incorporation mechanisms were based on experimental results from such techniques as secondary ion mass spectrometry, Auger electron spectroscopy, and C-V measurements. In the present study, electron microscopy was used in combination with cross-section specimen preparation. The information on the morphology and microstructure of the surface accumulation can be obtained in a fine scale and may confirm several suggestions from indirect experimental evidence in the previous studies.

The Effects of Nitrogen on Electrical and Structural Properties in TaSixNy/SiO2/p-Si MOS Capacitors

2002 ◽  
Vol 716 ◽  
Author(s):  
You-Seok Suh ◽  
Greg Heuss ◽  
Jae-Hoon Lee ◽  
Veena Misra
Keyword(s):  
Structural Properties ◽  
Electron Spectroscopy ◽  
Oxygen Diffusion ◽  
Gate Dielectric ◽  
Barrier Properties ◽  
Reaction Rates ◽  
Cross Sectional ◽  
Mos Capacitors ◽  
Transmission Electron ◽  
Thermal Stability Of

AbstractIn this work, we report the effects of nitrogen on electrical and structural properties in TaSixNy /SiO2/p-Si MOS capacitors. TaSixNy films with various compositions were deposited by reactive sputtering of TaSi2 or by co-sputtering of Ta and Si targets in argon and nitrogen ambient. TaSixNy films were characterized by Rutherford backscattering spectroscopy and Auger electron spectroscopy. It was found that the workfunction of TaSixNy (Si>Ta) with varying N contents ranges from 4.2 to 4.3 eV. Cross-sectional transmission electron microscopy shows no indication of interfacial reaction or crystallization in TaSixNy on SiO2, resulting in no significant increase of leakage current in the capacitor during annealing. It is believed that nitrogen retards reaction rates and improves the chemical-thermal stability of the gate-dielectric interface and oxygen diffusion barrier properties.

A New Method of Wafer Level Plan View TEM Sample Preparation by DualBeam

2008 ◽  
Author(s):  
Hyoung H. Kang ◽  
Michael A. Gribelyuk ◽  
Oliver D. Patterson ◽  
Steven B. Herschbein ◽  
Corey Senowitz
Keyword(s):  
Sample Preparation ◽  
Ex Situ ◽  
Wafer Level ◽  
Cross Sectional ◽  
Plan View ◽  
Manufacturing Line ◽  
Transmission Electron ◽  
Thin Lamella ◽  
Preparation Techniques

Abstract Cross-sectional style transmission electron microscopy (TEM) sample preparation techniques by DualBeam (SEM/FIB) systems are widely used in both laboratory and manufacturing lines with either in-situ or ex-situ lift out methods. By contrast, however, the plan view TEM sample has only been prepared in the laboratory environment, and only after breaking the wafer. This paper introduces a novel methodology for in-line, plan view TEM sample preparation at the 300mm wafer level that does not require breaking the wafer. It also presents the benefit of the technique on electrically short defects. The methodology of thin lamella TEM sample preparation for plan view work in two different tool configurations is also presented. The detailed procedure of thin lamella sample preparation is also described. In-line, full wafer plan view (S)TEM provides a quick turn around solution for defect analysis in the manufacturing line.

Growth of Epitaxial IrSi3 Layers on Si(111)

1989 ◽  
Vol 160 ◽  
Author(s):  
T. L. Lin ◽  
C. W. Nieh
Keyword(s):  
Surface Morphology ◽  
Molecular Beam ◽  
Solid Phase ◽  
Single Mode ◽  
Growth Conditions ◽  
Tem Analysis ◽  
Mbe Growth ◽  
Good Surface ◽  
Transmission Electron

AbstractEpitaxial IrSi3 films have been grown on Si (111) by molecular beam epitaxy (MBE) at temperatures ranging from 630 to 800 °C and by solid phase epitaxy (SPE) at 500 °C. Good surface morphology was observed for IrSi3 layers grown by MBE at temperatures below 680 °C, and an increasing tendency to form islands is noted in samples grown at higher temperatures. Transmission electron microscopy (TEM) analysis reveals that the IrSi3 layers grow epitaxially on Si(111) with three epitaxial modes depending on the growth conditions. For IrSi3 layers grown by MBE at 630 °C, two epitaxial modes were observed with ~ 50% area coverage for each mode. Single mode epitaxial growth was achieved at a higher MBE growth temperature, but with island formation in the IrSi3 layer. A template technique was used with MBE to improve the IrSi3 surface morphology at higher growth temperatures. Furthermore, single-crystal IrSi3 was grown on Si(111) at 500 °C by SPE, with annealing performed in-situ in a TEM chamber.

Oxidation Kinetics of Cu-Ni Alloy Observed by in situ UHV-TEM

2007 ◽  
Vol 1026 ◽  
Author(s):  
Li Sun ◽  
John E. Pearson ◽  
Judith C. Yang
Keyword(s):  
High Vacuum ◽  
Alloy Film ◽  
Ultra High Vacuum ◽  
Cross Sectional ◽  
Primary Mechanism ◽  
Transmission Electron ◽  
Ni Alloy ◽  
Cu Oxidation ◽  
Kinetics Of

AbstractThe nucleation and growth of Cu2O and NiO islands due to oxidation of Cu-24%Ni(001) films were monitored at various temperatures by in situ ultra-high vacuum (UHV) transmission electron microscopy (TEM). In remarkable contrast to our previous observations of Cu and Cu-Au oxidation, irregular-shaped polycrystalline oxide islands were observed to form with respect to the Cu-Ni alloy film, and an unusual second oxide nucleation stage was noted. Similar to Cu oxidation, the cross-sectional area growth rate of the oxide island is linear indicating oxygen surface diffusion is the primary mechanism of oxide growth.

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