Real-Time Optical Diagnostics For Measuring And Controlling Epitaxial Growth

1991 ◽  
Vol 222 ◽  
Author(s):  
D. E. Aspnes ◽  
R. Bhat ◽  
E. Colas ◽  
L. T. Florez ◽  
S. Gregory ◽  
...  
Keyword(s):  
Molecular Beam ◽  
Chemical Vapor ◽  
Optical Methods ◽  
Surface Processes ◽  
Microstructural Properties ◽  
Difference Spectroscopy ◽  
Semiconductor Crystal ◽  
Dynamic Surface ◽  
Control Growth ◽  
Reflectance Difference Spectroscopy

ABSTRACTA variety of optical methods are now available for studying surface processes and for monitoring layer thicknesses and compositions during semiconductor crystal growth by molecular beam epitaxy (MBE), organometallic chemical vapor deposition (OMCVD), and related techniques. New capabilities for surface analysis are being provided by developing techniques such as reflectance-difference spectroscopy (RDS), which use intrinsic symmetries to suppress ordinarily dominant bulk contributions. Bulk and microstructural properties such as compositions and layer thicknesses can be determined by techniques such as spectroellipsometry (SE), which return information integrated over the penetration depth of light. Recent advances include the application of reflectance to monitor dynamic surface processes, RDS to characterize (001) GaAs surfaces in OMCVD environments, and SE to control growth of AlxGa1-x, As materials and structures.

In situ reflectance difference spectroscopy of N-plasma doped ZnTe grown by molecular beam epitaxy

1998 ◽  
Vol 73 (26) ◽  
pp. 3857-3859 ◽  
Author(s):  
D. Stifter ◽  
M. Schmid ◽  
K. Hingerl ◽  
A. Bonanni ◽  
M. Garcia-Rocha ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Difference Spectroscopy ◽  
Reflectance Difference Spectroscopy

scholarly journals Real-time reflectance-difference spectroscopy of GaAs molecular beam epitaxy homoepitaxial growth

APL Materials ◽  
2014 ◽  
Vol 2 (3) ◽  
pp. 032107 ◽  
Author(s):  
A. Lastras-Martínez ◽  
J. Ortega-Gallegos ◽  
L. E. Guevara-Macías ◽  
O. Nuñez-Olvera ◽  
R. E. Balderas-Navarro ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Real Time ◽  
Molecular Beam ◽  
Difference Spectroscopy ◽  
Homoepitaxial Growth ◽  
Reflectance Difference Spectroscopy

Optical Approaches to Real-Time Analysis and Control of Crystal Growth

1990 ◽  
Vol 198 ◽  
Author(s):  
D. E. Aspnes
Keyword(s):  
Chemical Vapor Deposition ◽  
Crystal Growth ◽  
Molecular Beam Epitaxy ◽  
Real Time ◽  
Vapor Deposition ◽  
Molecular Beam ◽  
Second Harmonic ◽  
Chemical Vapor ◽  
Optical Methods ◽  
Dielectric Anisotropy

ABSTRACTA variety of optical methods are now available for studying surface processes and for monitoring layer thicknesses and compositions during semiconductor crystal growth by molecular beam epitaxy (MBE), organometallic chemical vapor deposition (OMCVD), and related techniques. Spectroellipsometry (SE) and spectroreflectometry (SR), the older, primarily bulk-sensitive probes, are now augmented by new, primarily surface-sensitive probes such as reflectance-difference spectroscopy (RDS), second-harmonic generation (SHG), and laser light scattering (LLS). Examples of real-time growth studies now include SE determinations of thicknesses and compositions of AlxGa1–xAs layers on GaAs by organometallic molecular beam epitaxy (OMMBE) to 10 Å thickness scales, RDS determinations of surface dielectric anisotropy spectra of various (001) GaAs surfaces relevant to crystal growth by MBE, and LLS determinations of the evolution of surface roughness during chemical vapor deposition (CVD) growth on Si. Proven capabilities suggest new applications, particularly to growth-interrupted and metastable systems.

Surface reconstruction of GaAs (001) during OMCVD growth

1993 ◽  
Vol 344 (1673) ◽  
pp. 443-452 ◽  
Keyword(s):  
Surface Reconstruction ◽  
Atmospheric Pressure ◽  
Molecular Beam ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy ◽  
Difference Spectroscopy ◽  
Reflectance Difference Spectroscopy ◽  
Surface Reconstructions

Surface reconstruction of GaAs (001) during organometallic chemical vapour deposition (OMCVD) growth has been investigated with reflectance-difference spectroscopy (RDS). RD spectra reveal that surface reconstructions similar or identical to (4 x 2), (2 x 4), and c (4 x 4) that occur on surface prepared by molecular beam epitaxy (MBE) in ultrahigh vacuum (UHV) occur even in atmospheric pressure OMCVD growth environments. Based on the RDS database we established on static surfaces in UHV , we studied the structure of surfaces under both static and dynamic conditions in non-UHV ambients. We find, in contrast to previous models, that the surfaces under various non-UHV conditions exhibit dimer formation. In addition, OMCVD growth and atomic layer epitaxy (ALE) typically occur under disordered c (4 x 4)[ d (4 x 4)]-like conditions where the surface is terminated by multilayers of As. When trimethylgallium (TMG) and arsine (AsH 3 ) are supplied simultaneously, the surface structure varies as a function of the supply rates of TMG and AsH 3 , and the substrate temperature.

Reflectance-Difference Spectroscopy: a New Real-Time, In-Situ Analysis of MBE and OMCVD Growth Surfaces.

1988 ◽  
Vol 144 ◽  
Author(s):  
E. Colas ◽  
D.E. Aspnes ◽  
R. Bhat ◽  
A.A. Studna ◽  
M.A. Koza ◽  
...  
Keyword(s):  
Real Time ◽  
Structural Changes ◽  
Chemical Vapor ◽  
Growth Surface ◽  
Semiconductor Surface ◽  
Difference Spectroscopy ◽  
Kcal Mole ◽  
Large Size ◽  
Reflectance Difference Spectroscopy

ABSTRACTReflectance-difference spectroscopy (RDS) is a recently developed optical technique that allows to monitor chemical and structural changes at a growing semiconductor surface, in-situ and in real-time. This technique was applied recently to organometallic chemical vapor deposition (OMCVD) on a [100] GaAs growth surface. The results show that submonolayer coverage of reacted species can be followed by this technique, which provided unique insights into the microscopic growth mechanisms. The time, temperature and pressure dependences of surface coverage show that OMCVD growth is controlled by two basic processes with distinct activation energies, i.e. reversible chemisorption (at -26 kcal/mole), and decomposition (at 39 kcal/mole) of trimethylgallium (TMG) at surface lattice sites. The importance of reversible chemisorption, which is of an excluded-volume type, due to the large size of the TMG molecule, had been overlooked until now in the literature, where only one activation energy was used to describe growth kinetics.

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