TY  - JOUR
AU  - Freter, Lars
AU  - Lymperakis, Liverios
AU  - Schnedler, Michael
AU  - Eisele, Holger
AU  - Jin, Lei
AU  - Liu, Jianxun
AU  - Sun, Qian
AU  - Dunin-Borkowski, Rafal E.
AU  - Ebert, Philipp
TI  - Composition dependence of intrinsic surface states and Fermi-level pinning at ternary Al x Ga1− x N m -plane surfaces
JO  - Journal of vacuum science & technology / A
VL  - 42
IS  - 2
SN  - 0734-2101
CY  - New York, NY
PB  - Inst.
M1  - FZJ-2024-04929
SP  - 023202
PY  - 2024
AB  - Growth on nonpolar group III-nitride semiconductor surfaces has been suggested to be a remedy for avoiding detrimental polarization effects. However, the presence of intrinsic surface states within the fundamental bandgap at nonpolar surfaces leads to a Fermi-level pinning during growth, affecting the incorporation of dopants and impurities. This is further complicated by the use of ternary, e.g., Al(x)Ga(1-x)N layers in device structures. In order to quantify the Fermi-level pinning on ternary group III nitride nonpolar growth surface, the energy position of the group III-derived empty dangling bond surface state at nonpolar Al(x)Ga(1-x)N (10-10) surfaces is determined as a function of the Al concentration using cross-sectional scanning tunneling microscopy and spectroscopy. The measurements show that the minimum energy of the empty dangling bond state shifts linearly toward midgap for increasing Al concentration with a slope of  ~5 meV/%. These experimental findings are supported by complementary density functional theory calculations.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:001153140000005
DO  - DOI:10.1116/6.0003225
UR  - https://juser.fz-juelich.de/record/1029011
ER  -