Publication Date:
2016-03-23
Description:
Complementary studies of atom probe tomography, secondary ion mass spectrometry, and vertical current-voltage measurements are carried out in order to unravel the influence of C-doping of GaN on the vertical leakage current of AlN/AlGaN/GaN:C heterostructures. A systematic increment of the vertical blocking voltage at a given current density is observed in the structures, when moving from the nominally undoped conditions—corresponding to a residual C-background of ∼10 17 cm −3 —to a C-content of ∼10 19 cm −3 in the GaN layer. The value of the vertical blocking voltage saturates for C concentrations higher than ∼10 19 cm −3 . Atom probe tomography confirms the homogeneity of the GaN:C layers, demonstrating that there is no clustering at C-concentrations as high as 10 20 cm −3 . It is inferred that the vertical blocking voltage saturation is not likely to be related to C-clustering.
Print ISSN:
0021-8979
Electronic ISSN:
1089-7550
Topics:
Physics
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