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Bridgman-type apparatus for the study of growth-property relationships - Arsenic vapor pressure-GaAs property relationshipA precision Bridgman-type apparatus is described which was designed and constructed for the investigation of relationships between crystal growth parameters and the properties of GaAs crystals. Several key features of the system are highlighted, such as the use of a heat pipe for precise arsenic vapor pressure control and seeding without the presence of a viewing window. Pertinent growth parameters, such as arsenic source temperature, thermal gradients in the growing crystal and in the melt, and the macroscopic growth velocity can be independently controlled. During operation, thermal stability better than + or - 0.02 C is realized; thermal gradients can be varied up to 30 C/cm in the crystal region, and up to 20 C/cm in the melt region; the macroscopic growth velocity can be varied from 50 microns/hr to 6.0 cm/hr. It was found that the density of dislocations depends critically on As partial pressure; and essentially dislocation-free, undoped, crystals were grown under As pressure precisely controlled by an As source maintained at 617 C. The free carrier concentration varied with As pressure variations. This variation in free carrier concentration was found to be associated with variations in the compensation ratio rather than with standard segregation phenomena.
Document ID
19820040251
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Parsey, J. M.
(Massachusetts Inst. of Tech. Cambridge, MA, United States)
Nanishi, Y.
(Massachusetts Inst. of Tech. Cambridge, MA, United States)
Lagowski, J.
(Massachusetts Inst. of Tech. Cambridge, MA, United States)
Gatos, H. C.
(MIT Cambridge, MA, United States)
Date Acquired
August 10, 2013
Publication Date
February 1, 1982
Publication Information
Publication: Electrochemical Society
Subject Category
Solid-State Physics
Accession Number
82A23786
Distribution Limits
Public
Copyright
Other

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