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Influence of Predeposition on the Properties of GaN
Author(s) -
Franzheld R.,
Seifert W.,
Butter E.
Publication year - 1986
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.2170210732
Subject(s) - impurity , epitaxy , materials science , sapphire , vapor phase , chemical vapor deposition , analytical chemistry (journal) , chemical engineering , chemistry , optoelectronics , nanotechnology , thermodynamics , layer (electronics) , optics , chromatography , laser , physics , organic chemistry , engineering
Growth experiments with GaN in the system Ga/HCl/NH 3 /He or H 2 were carried out in a reactor with two deposition zones. The extent of the reaction in the first zone, called the predeposition zone, is controlled by the NH 3 flow rate. In the second zone GaN is deposited epitaxially onto sapphire substrates. The variation of the carrier concentration of these epilayers indicates the dominating effect of impurities especially oxygen in opposition to the widely accepted vacancy model. Due to the high incorporation ratio of donor impurities into the solid a predeposition reduces the impurity content in the vapour phase. A reduction of the free carrier concentration in the epitaxial layers could be achieved. Different behaviour in the two carrier gas systems could be established.