In:
Journal of Applied Physics, AIP Publishing, Vol. 114, No. 2 ( 2013-07-14)
Abstract:
We report magnetotransport measurements performed on AlGaN/GaN devices with different buffer layers. Standard samples with a 1 μm thick GaN buffer show a linear Hall resistance and an almost constant magnetoresistance, as expected from a single two-dimensional electron gas (2DEG) at the AlGaN/GaN interface. Other samples, with an AlxGa1–xN buffer (x = 5%) and a buried linear aluminium gradient, have an additional three-dimensional electron slab (3DES) close to the GaN substrate. In this case, the Hall resistance is strongly non-linear and presents an incorrect hole-type carrier signature, evidenced by low field mobility spectrum analysis. This effect is strengthened when the 3D layer, parallel to the mesa-etched 2DEG, is infinite. We suggest that the misplacement of the electrical contacts in the 3DES, i.e., far from the sample edges, could explain the wrong carrier type determination.
Type of Medium:
Online Resource
ISSN:
0021-8979
,
1089-7550
Language:
English
Publisher:
AIP Publishing
Publication Date:
2013
detail.hit.zdb_id:
220641-9
detail.hit.zdb_id:
3112-4
detail.hit.zdb_id:
1476463-5
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