PowerPoint Presentation*
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE GROWTH AND INSTRUMENTATION
Master of Science
Dr. Terry Golding, Supervisor /Committee Member
Dr. Vijay Vaidyanathan, Committee Member
Dr. Albert B. Grubbs, Jr., Chair of the
Department Of Engineering technology
University of North Texas
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE GROWTH AND INSTRUMENTATION
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE GROWTH AND INSTRUMENTATION
Problem Statement
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE GROWTH AND INSTRUMENTATION
Operating softwares such as SpecVIEW, Video RHEED Intensity Measurement Program, Spectramass 2000 software.
Developing a LabVIEW program for the acquisition of images and calculating the sample growth rate.
Using the program to study the growth of GaP using atomic phosphorus.
Purpose of Research
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE GROWTH AND INSTRUMENTATION
Identifying and overcoming the various limitations during MBE growth process
To write a LabVIEW program to acquire and analyze images using existing devices in the market at a minimum cost
Set up the III/V MBE system for growth of GaP samples through the use of a phosphorous cracker
Research Question
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE Growth and Instrumentation/ Statement of Need
Molecular Beam Epitaxy
Reduced temperatures. For example about 500-600oC for GaAs.
Reduced handling requirements of toxic materials such as As.
The ability to abruptly cease or initiate molecular beams producing hyperabrupt surfaces.
Facility of in situ analysis during growth.
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE Growth and Instrumentation/ Statement of Need
Electron Diffraction
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
Crystal Structure
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE Growth and Instrumentation/ Statement of Need
Electron Diffraction
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE Growth and Instrumentation/ Statement of Need
Electron diffraction:
The electron density of a crystal can be represented in Fourier series in single dimension as
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE Growth and Instrumentation / Statement of Need
Extending the analysis to three dimensional lattice structures,
where is called the reciprocal lattice vector and is given by
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE Growth and Instrumentation / Statement of Need
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE Growth and Instrumentation / Statement of Need
RHEED Patterns
Fig (6.a) RHEED patterns and the corresponding electron micrographs of GaAs grown using MBE GaAs heated in vacuum
to 580oC for 5min.
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE Growth and Instrumentation / Statement of Need
RHEED OSCILLATIONS
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE Growth and Instrumentation / Research Plan
LabVIEW
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE Growth and Instrumentation / Research Plan
A subVI to store the images.
A subVI to mesaure the intensity of images at a particular region of interest, continuously in time.
A subVI to plot the Intensity vs Time graph of the measured intensity.
A subVI to calculate the growth rate of the sample.
LabVIEW
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE Growth and Instrumentation / Research Plan
Cleaning the view ports: in the ratio of 1:2:10
Checking the crucibles.
Aligning the linear transfer rod.
Venting the chamber.
Preparing the III/V Chamber
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE Growth and Instrumentation / Assumptions
The terms and formulas used will require a basic knowledge of mathematics, engineering and physics.
The software implementation will require knowledge of LabVIEW, DOS and Windows Operating environment.
The experiments will be carried out based on the evidence available through prior research in this field. It will be assumed that similar or required growth environments have been established and the results will be analyzed accordingly.
The system is basically an III/V growth chamber and is assumed to work well at different temperatures and pressures with the materials not used previously within the chamber.
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE Growth and Instrumentation / Limitations
This research is limited only to get acquainted with the MBE growth process and instrumentation.
The proposed LabVIEW program shall be written for implementation only with the III/V MBE system.
The LabVIEW program is aimed only at displaying the intensity vs time graph and calculating the growth rate of the sample.
The measurements shall be taken on 4-6 samples.
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE Growth and Instrumentation / Review of Literature
Proposed by Gunther in 1958.
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE Growth and Instrumentation / Review of Literature
Schematic cross section of an advanced three- chamber UHV system designed for MBE growth and
detailed surface studies [10].
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE Growth and Instrumentation / Methodology
Introduction
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE Growth and Instrumentation / Methodology
Load-lock chamber of the III/V MBE system
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE Growth and Instrumentation / Methodology
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE Growth and Instrumentation / Methodology
Preparation chamber of the III/V MBE system
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE Growth and Instrumentation / Methodology
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE Growth and Instrumentation / Methodology
Growth chamber of III/V MBE system.
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE Growth and Instrumentation / Methodology
Spectramass PC2000 mass spectrometer software.
SpecView Plus software.
Vacuum pumps:
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE Growth and Instrumentation/ Methodology
Vacuum Pumps
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MBE Growth and Instrumentation / Methodology
Control Equipment
Furnace control unit housing rack
RHEED control Equipment
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MBE Growth and Instrumentation / Summary
Summary of the study.
Answer to research questions.
Conclusions based on the results and analysis of the study.
Strengths of the study.
Weakness of the study.
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE Growth and Instrumentation / Timeline
 
Timeline in Months
1 2 3 4 5 6 7 8 9 10 11 12
Review of Literature
Working with MBE
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MBE Growth and Instrumentation / References
http://mrlxp2.mrl.uiuc.edu/~rheed/index.html
Oscillations in the Surface Structure of Sn-doped GaAs during growth by MBE [Surf. Sci. 103, L90 (1981)] by J.J.Harris, B.A.Joyce and P.J.Dobson.
K.G. Gunther, Z.Naturforsch. 13A (1958) 1801; W. Hanlein, K.G. Gunther, in Advances in Vaccum Science & Technology (Proc. 1st Int. Congr. on Vacuum Techiques, Namur 1958) 727.
J.R.Arthur, J.Appl. Phys. 39 (1968) 4032.
C.Kittel, Introduction to Solid State Physics.
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE Growth and Instrumentation / References
A.Y.Cho, J. Vac. Sci. Technol. 8, S31 (1971).
http://www.ece.utexas.edu/projects/ece/mrc/groups/street_mbe/mbechapter
Davey, J.E. Pankey, T. 1968. J. Appl. Phys, 39: 1941-48.
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
MBE Growth and Instrumentation / References
MBE Varian 360 manual, Operations and Routine Maintenance, Varian Industrial Equipment Group,1978.
W.Braun. Applied RHEED. Reflection High-energy Electron Diffraction during Crystal Growth. 1999. Springer Tracts in Modern Physics, 154. 2. The Spectramass PC 2000 mass spectrometer manual, Kurt J.Lesker Co.
The Spectramass PC 2000 mass spectrometer manual, Kurt J.Lesker Co.
Spec View Plus software – User Guide, Spec View LLC, February 1, 2000.
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
QUESTIONS????
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M B E G R O W T H A N D I N U S T R U M E N T A T I O N
Thank you……