1MBEGROWTHANDINSTRUMENTATION. 2MBEGROWTHANDINSTRUMENTATION MBE GROWTH AND INSTRUMENTATION Thesis...

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MBE GROWTH AND INSTRUMENTATIONMBE GROWTH AND INSTRUMENTATION

Thesis Proposal Outline for the Degree of

Master of Science

Major Professor

Dr. Terry Golding Ph.D,

University of North Texas

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MBE GROWTH AND INSTRUMENTATIONMBE GROWTH AND INSTRUMENTATION

MBE growth.

RHEED.

Research Method.

References

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MBE GrowthMBE Growth

Introduction.

Description of MBE system and functioning.

Advantages and applications.

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MBE GROWTH-INTRODUCTIONMBE GROWTH-INTRODUCTION

Schematic illustration of basic evaporation process for MBE

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MBE GROWTHMBE GROWTHDESCRIPTION AND FUNCTIONINGDESCRIPTION AND FUNCTIONING

Schematic cross section of an advanced three- chamber UHV system designed for MBE growth

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MBE GROWTHMBE GROWTH APPLICATIONS AND ADVANTAGES APPLICATIONS AND ADVANTAGES

Growth of electronic and photonic devices such as solar cells, diode lasers, LEDs and heterojunction bi-polar junction transistor.

Slow growth rate of ~1μm. Reduced temperatures of about 500-600oC 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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RHEED - INTRODUCTIONRHEED - INTRODUCTION

Powerful tool for in situ analysis during the growth process.

Used to calibrate growth rates. Observe removal of oxides from the substrate. Calibrate the substrate temperature. Monitor the arrangement of surface atoms. Give a beedback on surface morphology.

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RHEED RHEED PRINCIPLE OF OPERATION PRINCIPLE OF OPERATION

RHEED Gun setup for MBE growth

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RHEED - OSCILLATIONSRHEED - OSCILLATIONS

Video tape stills of Sn-modified Rheed patterns from As-stabilized (001) GaAs at 550oC: (a) Without Ga flux (b) Immediately after applying Ga flux.

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RHEED OSCILLATIONS PLOTRHEED OSCILLATIONS PLOT

Recorder traces of intensity as a function of time at the

point A

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RHEED – INTENSITY VARIATIONSRHEED – INTENSITY VARIATIONS

Illustration of RHEED spot oscillations during the

growth of a monolayer

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RHEED PATTERNS – AN EXAMPLE RHEED PATTERNS – AN EXAMPLE

RHEED patterns and the corresponding electron micrographs of (110) GaAs grown using MBE : (a) GaAs heated in vaccum to 580oC for 5min. (b) 150oA layer

of GaAS on the surface of (a). (c) 1µm of GaAs deposited on surface of (a )

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MBE – RESEARCH METHODMBE – RESEARCH METHOD

Experimental. Video RHEED Intensity Measurement System. LabVIEW, frame grabber cards. Specview. Spectramass PC2000.

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MBE - REFERENCESMBE - REFERENCES

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.

A.Y.Cho, J. Vac. Sci. Technol. 8, S31 (1971). Molecular Beam Epitaxy of III-V Compounds: Technology and Grwoth

Process, by Klaus Proog. Ann. Rev. Material Sci. 1981. 11-171-210. W.Braun. Applied RHEED. Reflection High-energy Electron, Diffraction

during Crystal Growth. 1999. Springer Tracts in Modern Physics, 154. 2. A. Y. Cho, Key papers in Applied Physics – Molecular Bem Epitaxy, AIP

Press 1999. http://mrlxp2.mrl.uiuc.edu/~rheed/index.html http://www.ece.utexas.edu/projects/ece/mrc/groups/street_mbe/mbechapter

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QUESTIONS???QUESTIONS???

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Thank you…..Thank you…..

1MBEGROWTHANDINSTRUMENTATION. 2MBEGROWTHANDINSTRUMENTATION MBE GROWTH AND INSTRUMENTATION Thesis...

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