Block Copolymer Templating for Formation of Quantum Dots and Lattice Mismatched Semiconductor Structures

2010 ◽  
Vol 1258 ◽  
Author(s):  
Smita Jha ◽  
Chi-Chun Liu ◽  
Joo Hyung Park ◽  
Monika K. Wiedmann ◽  
T S Kuan ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Block Copolymer ◽  
Self Assembly ◽  
Strain Relaxation ◽  
Selective Area Growth ◽  
Regular Array ◽  
Defect Reduction ◽  
Precise Control ◽  
Semiconductor Structures ◽  
Selective Area

AbstractTemplated growth for the fabrication of semiconductor nanostructures such as quantum dots and lattice-mismatched structures has been employed in this study. Self assembly of block copolymers (BCP) has been exploited to create a regular array of nanoscale patterns on a substrate to generate the growth template. These patterned templates were used for the selective area growth of pseudomorphic quantum dots, allowing for precise control over the dot size and spatial distribution. Strain relaxation in lattice-mismatched structures grown past the pseudomorphic limit was also studied. Analysis of the grown structures suggests that this approach using block copolymer templating followed by selective growth can be used for defect reduction in lattice-mismatched materials.

scholarly journals Submicron active-passive integration with position and number controlled InAs∕InP (100) quantum dots (1.55μm wavelength region) by selective-area growth

2007 ◽  
Vol 91 (13) ◽  
pp. 131102 ◽  
Author(s):  
D. Zhou ◽  
S. Anantathanasarn ◽  
P. J. van Veldhoven ◽  
F. W. M. van Otten ◽  
T. J. Eijkemans ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Wavelength Region ◽  
Selective Area Growth ◽  
Selective Area ◽  
Area Growth

scholarly journals Anomalous Stranski-Krastanov growth of (111)-oriented quantum dots with tunable wetting layer thickness

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Christopher F. Schuck ◽  
Simon K. Roy ◽  
Trent Garrett ◽  
Qing Yuan ◽  
Ying Wang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Self Assembly ◽  
Tensile Strain ◽  
Quantum Systems ◽  
Growth Mode ◽  
Wetting Layer ◽  
Precise Control ◽  
Growth Regime ◽  
Inp Substrates ◽  
Lattice Matched

AbstractDriven by tensile strain, GaAs quantum dots (QDs) self-assemble on In0.52Al0.48As(111)A surfaces lattice-matched to InP substrates. In this study, we show that the tensile-strained self-assembly process for these GaAs(111)A QDs unexpectedly deviates from the well-known Stranski-Krastanov (SK) growth mode. Traditionally, QDs formed via the SK growth mode form on top of a flat wetting layer (WL) whose thickness is fixed. The inability to tune WL thickness has inhibited researchers’ attempts to fully control QD-WL interactions in these hybrid 0D-2D quantum systems. In contrast, using microscopy, spectroscopy, and computational modeling, we demonstrate that for GaAs(111)A QDs, we can continually increase WL thickness with increasing GaAs deposition, even after the tensile-strained QDs (TSQDs) have begun to form. This anomalous SK behavior enables simultaneous tuning of both TSQD size and WL thickness. No such departure from the canonical SK growth regime has been reported previously. As such, we can now modify QD-WL interactions, with future benefits that include more precise control of TSQD band structure for infrared optoelectronics and quantum optics applications.

New approach of Nano-Selective Area Growth (NSAG) for a precise control of GaN nanodots grown by MOVPE

2008 ◽  
Vol 147 (2-3) ◽  
pp. 114-117 ◽  
Author(s):  
J. Martin ◽  
A. Martinez ◽  
W.H. Goh ◽  
S. Gautier ◽  
N. Dupuis ◽  
...  
Keyword(s):  
Selective Area Growth ◽  
New Approach ◽  
Precise Control ◽  
Selective Area ◽  
Area Growth

GaAs Quantum Dots by MOCVD

1992 ◽  
Vol 283 ◽  
Author(s):  
Takashi Fukui ◽  
Seigo Ando
Keyword(s):  
Quantum Dots ◽  
Chemical Vapor ◽  
Energy Shift ◽  
Emission Peak ◽  
Buffer Layers ◽  
Selective Area Growth ◽  
Selective Area ◽  
Atomic Force ◽  
Triangular Area ◽  
20 Nm

ABSTRACTNew GaAs quantum dots called tetrahedral quantum dots (TQDs) were fabricated using selective area metalorganic chemical vapor deposition (MOCVD). GaAs sub-micron crystals were completely buried in AlGaAs with single growth run without any processing damage at heterojunction interface. The substrates were SiO2 masked (111)B GaAs, which are partially etched free of SiO2 over triangular area using electron beam lithograpy and reactive ion etching techniques. First, truncated tetrahedral AlGaAs buffer layers with {110} facet sidewalls were grown in triangular area. Next, GaAs TQDs were sequentially grown on the top of AlGaAs. Finally, AlGaAs layers were overgrown on the resulting tetrahedral structures. The shape of GaAs tetrahedron was measured by an atomic force microscope(AFM). The size of bottom triangle of GaAs TQDs were estimated to be 20 nm. The size fluctuation was about 2%, which means that uniformity of selective area growth is excellent. Photoluminescence of GaAs TQDs buried in AlGaAs was measured at 8.5K. A clear emission peak from GaAs TQDs was observed at 810 nm. The energy shift from the GaAs emission peak is 19meV, which agrees well with the calculation. The results suggest that the selective area MOCVD method is very promising to fabricate GaAs quantum dots.

Insitudefinition of semiconductor structures by selective area growth and etching

1991 ◽  
Vol 59 (16) ◽  
pp. 2019-2021 ◽  
Author(s):  
E. Colas ◽  
C. Caneau ◽  
M. Frei ◽  
E. M. Clausen ◽  
W. E. Quinn ◽  
...  
Keyword(s):  
Selective Area Growth ◽  
Semiconductor Structures ◽  
Selective Area ◽  
Area Growth

Selective area growth of InAs quantum dots formed on a patterned GaAs substrate

2004 ◽  
Vol 85 (12) ◽  
pp. 2337-2339 ◽  
Author(s):  
S. Birudavolu ◽  
N. Nuntawong ◽  
G. Balakrishnan ◽  
Y. C. Xin ◽  
S. Huang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Gaas Substrate ◽  
Selective Area Growth ◽  
Inas Quantum Dots ◽  
Selective Area ◽  
Area Growth

In-plane InGaAs/Ga(As)Sb nanowire based tunnel junctions grown by selective area molecular beam epitaxy

2021 ◽  
Author(s):  
Alexandre Bucamp ◽  
Christophe Coinon ◽  
Sylvie Lepilliet ◽  
David Troadec ◽  
Gilles Patriarche ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Strain Relaxation ◽  
Tunnel Diodes ◽  
Precise Control ◽  
Selective Area ◽  
Large Peak ◽  
Current Densities ◽  
Composition Fluctuations ◽  
The Impact

Abstract In-plane InGaAs/Ga(As)Sb heterojunction tunnel diodes are fabricated by selective area molecular beam epitaxy with two different architectures: either radial InGaAs core / Ga(As)Sb shell nanowires or axial InGaAs/GaSb heterojunctions. In the former case, we unveil the impact of strain relaxation and alloy composition fluctuations at the nanoscale on the tunneling properties of the diodes, whereas in the latter case we demonstrate that template assisted molecular beam epitaxy can be used to achieve a very precise control of tunnel diodes dimensions at the nanoscale with a scalable process. In both cases, negative differential resistances with large peak current densities are achieved.

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