Investigation of crucible materials in gradient freeze gallium arsenide crystal growth
Undoped synthesized GaAs and crystals grown by the gradient freeze method were analyzed by room temperature Hall effect for net carrier density, secondary ion mass spectroscopy for Si and residual impurity concentrations, localized vibrational mode spectroscopy for C concentration, and optical absorption for neutral EL2 concentration. Impurity compensation was examined to determine limits for Si content in semi-insulating GaAs. Boules synthesized in various materials are used to determine the residual impurity densities contributing to compensation. Shallow donor densities below the residual acceptor concentration resulted in semi-insulating electronic properties for two synthesis boules. The Si incorporation rate in gradient freeze crystals is quantified through the deviation of net donor concentration from the normal freeze distribution. Crystals grown As-rich, Ga-rich and near-stoichiometric composition in SiO/sub 2/ crucibles show order-of-magnitude differences of Si incorporation rate. Crystals grown in Al/sub 2/O/sub 3/ and graphite crucibles have <10/sup -2/ and >3 times the incorporation rates of gradient freeze GaAs grown in SiO/sub 2/ crucibles. Crystals grown in a vertical gradient freeze configuration have <1/7 the incorporation rate of those grown horizontally. A vapor mechanism for incorporation of Si is indicated that contributes enough Si to preclude semi-insulating properties. At high values of net donor density, an acceptor density is seen that may be of native defect origin and is positively correlated with net donor density. 63 refs., 16 figs., 6 tabs.
- Research Organization:
- Lawrence Berkeley Lab., CA (USA)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 5573510
- Report Number(s):
- LBL-24650; ON: DE88006333
- Resource Relation:
- Other Information: Thesis (M.S.). Portions of this document are illegible in microfiche products. Thesis
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GALLIUM ARSENIDES
CRYSTAL GROWTH
ALUMINIUM OXIDES
CARRIER DENSITY
CRUCIBLES
GRAPHITE
HALL EFFECT
IMPURITIES
LINERS
SILICA
SILICON
ALUMINIUM COMPOUNDS
ARSENIC COMPOUNDS
ARSENIDES
CARBON
CHALCOGENIDES
ELEMENTAL MINERALS
ELEMENTS
GALLIUM COMPOUNDS
MINERALS
NONMETALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PNICTIDES
SEMIMETALS
SILICON COMPOUNDS
SILICON OXIDES
360601* - Other Materials- Preparation & Manufacture