The effect of strain relaxation on electron transport in undoped Al0.25Ga0.75N/GaN heterostructures
Date
2007-11-01Source Title
Physica B: Condensed Matter
Print ISSN
0921-4526
Electronic ISSN
1873-2135
Publisher
Elsevier BV * North-Holland
Volume
399
Issue
2
Pages
132 - 137
Language
English
Type
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Abstract
The two-dimensional electron gas (2DEG) transport properties of two-step growth undoped Al0.25Ga0.75N/GaN heterostructures with
semi-insulating buffer, grown by MOCVD, were investigated in a temperature range of 20–350 K. Using the quantitative mobility
spectrum analysis (QMSA) method, it was shown that significant parallel conduction does not occur in worked structures. In-plain
growth axis strains are calculated using the total polarization-induced charge density taken as the sheet carrier density measured from the
Hall effect. It was found that the calculated strain values are in good agreement with those reported. Influences of the two-step growth
parameters such as growth ramp time, the annealing temperature of the GaN nucleation layer on the mobility, and density of the 2DEG
are also discussed.