Coexistence properties of phase separation and CuPt-ordering in InGaAsP grown on GaAs substrates by organometallic vapor phase epitaxy

ABSTRACTEpitaxial (100) CdTe layers have been grown by organometallic vapor phase epitaxy (OMVPE) on GaAs and Si substrates. A thin layer of CdTe was first grown by atomic layer epitaxy (ALE) on GaAs substrates followed by thicker CdTe layer by conventional organometallic vapor phase epitaxy (OMVPE). This process resulted in high quality (100) CdTe on GaAs substrates. On Si substrates, direct growth of CdTe resulted in only polycrystalline layers. Hence, a thin Ge buffer layer grown at low temperature followed by an interfacial layer of ZnTe was used to get high quality (100) CdTe on Si. The process developed here eliminates the high temperature (>850°C) deoxidation step generally required when Si substrates are used. The CdTe layers were characterized by X-ray diffraction and optical microscopy. X-ray rocking curve with full width at half maximum (FWHM) of about 260 arcsec has been obtained for a 4 um thick CdTe layer. The results presented demonstrate novel techniques to control the hetero-interfaces in order to grow high quality CdTe on GaAs and Si substrates.

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Threading Dislocations and Phase Separation in InGaAs Layers on GaAs Substrates Grown by Low-Temperature Metalorganic Vapor Phase Epitaxy

Japanese Journal of Applied Physics ◽

10.1143/jjap.44.6403 ◽

2005 ◽

Vol 44 (9A) ◽

pp. 6403-6411 ◽

Cited By ~ 10

Author(s):

Yasushi Takano ◽

Kazu Kobayashi ◽

Hideaki Iwahori ◽

Masayoshi Umezawa ◽

Sho Shirakata ◽

...

Keyword(s):

Phase Separation ◽

Low Temperature ◽

Vapor Phase ◽

Metalorganic Vapor Phase Epitaxy ◽

Vapor Phase Epitaxy ◽

Threading Dislocations ◽

Gaas Substrates

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Relaxed Inx.Ga1−xas Graded Buffers Grown With Organometallic Vapor Phase Epitaxy on GaAs

MRS Proceedings ◽

10.1557/proc-484-631 ◽

1997 ◽

Vol 484 ◽

Cited By ~ 1

Author(s):

M. T. Bulsara ◽

C. Leitz ◽

E. A. Fitzgerald

Keyword(s):

Surface Roughness ◽

Phase Separation ◽

Vapor Phase ◽

Vapor Phase Epitaxy ◽

Threading Dislocation ◽

Misfit Dislocations ◽

Organometallic Vapor Phase Epitaxy ◽

Cross Sectional ◽

Plan View ◽

Optimum Growth Temperature

AbstractInxGa1−xAs structures with compositionally graded buffers were grown with organometallic vapor phase epitaxy (OMVPE) on GaAs substrates and characterized with plan-view and cross-sectional transmission electron microscopy (PV-TEM and X-TEM), atomic force microscopy (AFM), and x-ray diffraction (XRD). The results show that surface roughness experiences a maximum at growth temperatures where phase separation occurs in In.Gal.,As. The strain fields from misfit dislocations induce this phase separation in the <110> directions. At growth temperatures above and below this temperature, the surface roughness decreases significantly; however, only growth temperatures above this regime ensure nearly complete relaxed graded buffers with the most uniform composition caps. With the optimum growth temperature for grading InxGa1−x,As determined to be 700 °C, it was possible to produce In0.33Ga0.67As diodes on GaAs with threading dislocation densities < 8.5 × 106/cm2.

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