Book/Report

FZJ-2018-04344

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png GaAs-Einkristallzucht mit totaler Flüssigeinkapselung im vertikalen Bridgman-Verfahren

Naeven, R. (Corresponding author)FZJ*

1993
Forschungszentrum Jülich GmbH Zentralbibliothek Verlag Jülich

Please use a persistent id in citations: http://hdl.handle.net/2128/19411

Report No.: Juel-2800

Abstract: GaAs-single crystals ($\varnothing$ : 52 mm - 68 mm) have been grown in a two-zone Bridgman/Stockbarger-type furnace. The liquid encapsulation vertical Bridgman technique was applied with quartz- or pBN-crucibles. For 2"-crystals a single crystal yield of nearly 100% was achieved with the total liquid encapsulation (TLE) method by the use of quartz crucibles. The TLE provides a thin. B$_{2}$O$_{3}$-layer (of ca. 0.1mm in the cylindrical region) between the GaAs and the crucible wallduring the growth process. A detailed documentation of the onset of polycrystalline growth (PG) is given. PG originates at the crystal surface and developes over macroscopic distances (mm - cm). The starting point is an enhanced dislocation densitiy which can be related to an incomplete B2O3-encapsulation of the GaAs. Further development is governed by polygonization processes until subgrain boundaries cause a tilt of neighbouring grains of more than 2°. In addition, some other aspects of the GaAs-crystals are documented: It was possible to grow very homogeneous crystals which exhibit no striations. Undoped material was semi-insulating ($\rho \geq$ 10$^{8}$ $\Omega$cm) even when using quartz crucibles. All analyzed growth twins were of the rotation type. They never grew in a pure quartzcrucible under total liquid encapsulation. In strongly Ga-rich melt, in the last growth phase, the growth front is built up of {111}-faces (growth direction: < 100 >). Drop-like structures, ordered in crystallographic directions, are found an the surface of Tedoped GaAs crystals.

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Contributing Institute(s):

1. Publikationen vor 2000 (PRE-2000)

Research Program(s):

1. 899 - ohne Topic (POF3-899) (POF3-899)

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Database coverage:

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