Observation of Heteroepitaxially Grown Organic Ultrathin Layers on Inorganic Substrates by In Situ RHEED and by STM

1989 ◽  
Vol 159 ◽  
Author(s):  
Masahiko Hara ◽  
Hiroyuki Sasabe ◽  
Akira Yamada ◽  
Anthony F. Garito
Keyword(s):  
Molecular Beam ◽  
Structural Investigation ◽  
Copper Phthalocyanine ◽  
High Energy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
System A ◽  
Ultrathin Layers ◽  
Inorganic Substrates

ABSTRACTAn organic molecular beam epitaxy (OMBE) system has been designed and constructed with in situ reflection high-energy electron diffraction (RHEED) specifically for the deposition of organic molefelar layers under ultrahigh vacuum (UHV), the order of 10–10 torr. The system is equipped with a portable UHV chamber which allows easy transfer of the OMBE film samples to a separate UHV scanning tunneling microscopy (STM) system. A structural investigation of heteroepitaxially grown organic ultrathin layers of copper phthalocyanine (CuPc) on inorganic substrates was carried out by the combined UHV system from less than a monolayer of CuPc.

Self-Assembled InAs Islands on (AI,Ga)As, an In Situ Scanning Tunneling Microscopy Study

1999 ◽  
Vol 571 ◽  
Author(s):  
P. Ballet ◽  
J.B. Smathers ◽  
G.J. Salamo
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Molecular Beam ◽  
Three Dimensional ◽  
Microscopy Study ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Self Organized ◽  
Scanning Tunneling Microscopy Study ◽  
Island Density

ABSTRACTWe report an in-situ molecular beam epitaxy – scanning tunneling microscopy study of three dimensional (3D) self organized InAs islands on (AI,Ga)As surfaces. The influence of the presence of Al atoms on the roughness of the starting surface and on the island density is shown by investigating several Al compositions. We emphasize the case of InAs/AlAs and point out the major differences between this system and the widely studied InAs/GaAs system.

scholarly journals Surface Reconstruction during Molecular Beam Epitaxial Growth of GaN (0001)

1998 ◽  
Vol 3 ◽  
Author(s):  
A. R. Smith ◽  
V. Ramachandran ◽  
R. M. Feenstra ◽  
D. W. Greve ◽  
A. Ptak ◽  
...  
Keyword(s):  
Molecular Beam ◽  
High Energy ◽  
Nitrogen Plasma ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Plasma Sources ◽  
Molecular Beam Epitaxial ◽  
Homoepitaxial Growth ◽  
Surface Reconstructions ◽  
Molecular Beam Epitaxial Growth

Surface reconstructions during homoepitaxial growth of GaN (0001) are studied using reflection high-energy electron diffraction and scanning tunneling microscopy. In agreement with previous workers, a distinct transition from rough to smooth morphology is seen as a function of Ga to N ratio during growth. However, in contrast to some prior reports, no evidence for a 2×2 reconstruction during GaN growth is observed. Observations have been made using four different nitrogen plasma sources, with similar results in each case. A 2×2 structure of the surface can be obtained, but only during nitridation of the surface in the absence of a Ga flux.

Surface Reconstructions of Strained Epitaxial CoSi2/Si(100) Layers Studied by Scanning Tunneling Microscopy.

1991 ◽  
Vol 237 ◽  
Author(s):  
R. Stalder ◽  
C. Schwarz ◽  
H. Sirringhaus ◽  
H. VON Känel
Keyword(s):  
Electron Diffraction ◽  
Scanning Tunneling Microscopy ◽  
High Energy ◽  
Real Space ◽  
Scanning Tunneling ◽  
High Energy Electron ◽  
Tunneling Microscopy ◽  
Detailed Surface ◽  
Surface Reconstructions

ABSTRACTEpitaxial single-domain CoSi2(100) layers were grown on Si(100) by use of a template technique. In-situ scanning tunneling microscopy (STM) and reflection high energy electron diffraction (RHEED) were used for a detailed surface study. The (√2×√2)R45 reconstruction of the Co-rich “C-surface” and the (3√2×√2)R45 as well as a newly discovered (√2×√2)R45 of the Si-rich “S-surface” were resolved in real space and are discussed in detail. The transition from the C- to the S-surface above 500 °C is related to a (2×2) reconstruction.

OPTICAL AND STRUCTURAL ANALYSIS OF Ge/Si QUANTUM DOTS GROWN ON A Si(001) SURFACE COVERED WITH A SiO2 SUB-MONOLAYER

2007 ◽  
Vol 06 (03n04) ◽  
pp. 245-248
Author(s):  
A. FONSECA ◽  
E. ALVES ◽  
J. P. LEITÃO ◽  
N. A. SOBOLEV ◽  
M. C. CARMO ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Molecular Beam ◽  
Broad Band ◽  
Sample Surface ◽  
High Energy ◽  
Scanning Tunneling ◽  
Hydrogen Passivation ◽  
Tunneling Microscopy ◽  
Grazing Angles ◽  
Si Quantum Dots

In this work we performed measurements of photoluminescence (PL), scanning tunneling microscopy (STM), and Rutherford backscattering (RBS) at grazing angles of incidence in a set of samples grown by molecular beam epitaxy, in which a Ge layer was deposited on a Si (001) substrate covered with a thin SiO 2 layer. Three different thicknesses for either layer were deposited: 0.5, 0.75 or 1 monolayer (ML) of SiO 2, and 0.3, 0.6 or 0.9 nm of Ge . The PL measurements for the samples with thicker layers show a broad band at ~ 0.85 eV superimposed on a dislocation related band at ~ 0.81 eV . The attribution of the high energy band to Ge islands in this sample is supported by STM and RBS measurements, as well as by PL measurements after hydrogen passivation of the sample surface. For the samples with thinner SiO 2 and Ge layers, no evidence for the formation of Ge islands was found.

Growth of Si on Ge(001)2×l by gas-source molecular beam epitaxy

1993 ◽  
Vol 51 ◽  
pp. 806-807
Author(s):  
H.Z. Xiao ◽  
R. Tsu ◽  
I.M. Robertson ◽  
H.K. Birnbaum ◽  
J.E. Greene
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Strain Relaxation ◽  
Misfit Strain ◽  
High Energy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Gas Source ◽  
High Quality Result ◽  
Strained Layer Superlattices

The growth of SiGe strained-layer superlattices (SLS) has been received considerable attention due to the electronic and optoelectronic properties of these layers. In addition, these structures offer tantalizing possibilities for "band gap engineering" through the use of strain and chemically ordered alloys. The remaining barriers to grow the SiGe SLS structures with high quality result from the generation of large densities of defects, such as dislocations, twins, stacking faults, etc., at the heterointerfaces arising from the misfit strain relaxation. Other problems associated with the growth of the SiGe SLS structures are segregation and low incorporation of the dopants and inter-diffusion of Si and Ge. In the present study, the inter-mixing of Si and Ge and the generation of the defects in Si epilayers grown on Ge(001)2×1 at 550 °C by gas-source molecular beam epitaxy (MBE) from Si2H6 were studied using transmission electron microscopy (TEM), in-situ reflection high-energy electron diffraction (RHEED), scanning tunneling microscopy (STM) and electron energy-loss spectroscopy (EELS).

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