RHEED Studies of Strained Layer Molecular Beam Epitaxy and Self Assembled Quantum Dots, Paul R. Berger
Student: Paul R. Berger (Ph.D 1990)
Advisor: Pallab K. Bhattacharya (University of Michigan, Ann Arbor)
Importance of the Problem:
Epitaxial growth prefers that the epilayer be lattice matched
to the substrate, or underlayer, to avoid the formation of misfit
dislocations created when a lattice mismatched layer exceeds its
critical thickness and it becomes energetically favorable to create
misfit dislocations. How the surface changes during strained growth
was not well known in the late 1980's, when in situ surface
studies using reflection high energy electron diffraction (RHEED)
provided a pathway to investigate the surface during strained
Brief Description of Our Work and Results:
Developed an understanding of self-assembled quantum dot formation by
the study of reflection high energy electron diffraction (RHEED) oscillations.
From the RHEED studies, surface kinetics were examined for various
alloys compositions and related to the constituents bond strengths.
Expanded the understanding of lattice mismatched strained layer systems
by developing a model of the MBE growth nucleation of the InGaAs on GaAs
system. Showed for the first time how strain modifies the growth kinetics
and thermodynamics which governs the strained growth modes. Proved a
favorability toward 3-D island growth under normal growth conditions when
the misfit exceeds about 2% which enable self-assembled quantum dot formation.
Also measured the shift in surface lattice constant during strained layer
epitaxy and illustrated metastable growth at reduced substrate temperatures.
Awards, Citations and Recognitions
- Cited in Physics Today (January 1989) as making significant progress in 1988
towards the understanding of defect generation and growth nucleation of
lattice mismatched strained layer systems.
Strained Layer Epitaxial Growth and Self-Assembled Quantum Dot Formation
- "Realization of In-Situ Sub Two-Dimensional Quantum Structures
by Strained Layer Growth Phenomena in the
System," J. Pamulapati, P. K. Bhattacharya, J. Singh,
P. R. Berger, C. W. Snyder, B. G. Orr, and R. L. Tober,
Journal of Electronic Materials, 25, pp. 479-483
PDF (1.25 MB)
- "Growth Phenomena and Characteristics of
Strained InxGa1-xAs on GaAs," J. Pamulapati,
P. Berger, K. Chang, J. Oh, Yi Chen, J. Singh, and P.
Bhattacharya, Journal of Crystal Growth, 95,
pp. 193-196 (1989).
- "Role of Strain and Growth Conditions on the Growth Front
Profile of InxGa1-xAs on GaAs During the
Pseudomorphic Growth Regime," Paul R. Berger, Kevin Chang,
Pallab Bhattacharya, Jasprit Singh and K. K. Bajaj, Applied
Physics Letters, 53, pp. 684-686 (August 22, 1988).
PDF (572 kB)
[Cited 206 times]
- "A Study of Strain Related Effects in the MBE Growth of
InxGa1-xAs on GaAs Using RHEED," Paul
R. Berger, Kevin Chang, Pallab K. Bhattacharya, and Jasprit
Singh, Journal of Vacuum Science and Technology B,
5, pp. 1162-1166 (July/August 1987).
PDF (536 kB)
[Cited 38 times]
- "Molecular Beam Epitaxial Growth and Luminescence
Multiquantum Wells On GaAs," Kevin Chang, Paul R. Berger,
Jasprit Singh, and Pallab K. Bhattacharya, Applied Physics
Letters, 51, pp. 261-263 (July 27, 1987).
PDF (395 kB)
- "A Comparative Study of the Growth processes of GaAs,
AlGaAs, InGaAs and InAlAs Lattice Matched and Non-lattice
Matched Semiconductors Using High Energy Electron Diffraction,"
Paul R. Berger, Pallab K. Bhattacharya, and Jasprit Singh,
Journal of Applied Physics, 61, pp. 2856-2860
(April 15, 1987).
PDF (789 kB)
[Cited 31 times]
- "Growth and Properties of
GaAs:In and InGaAs/GaAs
Multilayers," F-Y. Juang, W-P. Hong, P. R. Berger,
P. K. Bhattacharya, U. Das, and J. Singh, Journal of Crystal
Growth, 81, pp. 373-377 (1987).
- "Low Defect Densities in Molecular Beam Epitaxial
GaAs Achieved by Isoelectronic In Doping," Pallab K. Bhattacharya,
Sunada Dhar, Paul Berger, and Feng-Yuh Juang,
Applied Physics Letters, 49, pp. 470-472 (August 25, 1986).
PDF (279 kB)
Impact of Strained Layer Epitaxy Upon Device Performance
- "The Relation of the Performance Characteristics
(0 < x < 0.32) Modulation Doped Field Effect Transistors to Molecular
Beam Epitaxial Growth Modes," J. Pamulapati, R. Lai, G. I. Ng,
Y. C. Chen, P. R. Berger, P. K. Bhattacharya, J. Singh,
and D. Pavlidis, Journal of Applied Physics, 68,
pp. 347-350 (July 1, 1990).
PDF (777 kB)
- "Growth Modes of (100) InxGa1-xAs
Growth on GaAs Below Critical Thickness - Consequences for Pseudomorhic
MODFET's," P. R. Berger, Y. C. Chen, Jasprit Singh, and
P. Bhattacharya, 16th GaAs and Related Compounds Conference in
Karuizawa, Japan (1989).
- "Growth Phenomena and Characteristics of Strained
InxGa1-xAs on GaAs," J. Pamulapati, P. Berger, K. Chang,
J. Oh, Y. Chen, J. Singh, P. Bhattacharya, and R. Gibala, 5th
International Conference on Molecular Beam Epitaxy in Sapporo, Japan
- "In-Situ RHEED Studies to Understand the
Dislocation Formation Process in Growth of InGaAs on GaAs," Paul R.
Berger, Kevin Chang, Pallab K. Bhattacharya, Jasprit Singh, and
K. K. Bajaj, Advances in Semiconductors and Superconductors:
Physics and Device Applications in Newport Beach, CA (1988).
- "Dislocation Studies of Molecular Beam
Hetero-Epitaxial Growth of Strained InGaAs on GaAs," Kevin Chang, John
Mansfield, Ron Gibala, Paul R. Berger, Pallab K. Bhattacharya,
and Jasprit Singh, TMS/AIME Annual Meeting in Phoenix, AZ (1988).
- "Molecular Beam Hetero-epitaxial Growth of
Multiquantum Wells on GaAs with
In-situ RHEED Studies," Kevin Chang, Paul R. Berger, Pallab K.
Bhattacharya, Jasprit Singh, D. Van Aiken, and R. Gibala, 29th
Electronic Materials Conference in Santa Barbara, CA (1987).
- "TEM and RHEED Studies on MBE Growth of Strained
InGaAs/GaAs," Kevin Chang, Paul R. Berger, Pallab K. Bhattacharya,
Jasprit Singh, D. Van Aiken, and R. Gibala, American Physical Society
Meeting in New York, NY (1987).
- "A Study of Strain Related Effects in the
MBE Growth of InxGa1-xAs on GaAs Using RHEED,"
Paul R. Berger,
Kevin Chang, Pallab K. Bhattacharya, and Jasprit Singh, 14th
Physics and Chemistry of Semiconductor Interfaces Conference in
Salt Lake City, Utah (1987).
- "Growth and Properties of
GaAs: In and InGaAs/GaAs
Multilayers," F-Y. Juang, W-P. Hong, P. R. Berger, P. K. Bhattacharya,
U. Das, and J. Singh, 4th International Conference on Molecular
Beam Epitaxy in York, England (1986).
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