TY  - JOUR
AU  - Zhang, Lei
AU  - Portz, Verena
AU  - Schnedler, Michael
AU  - Jin, Lei
AU  - Wang, Yuhan
AU  - Hao, Xiaopeng
AU  - Eisele, Holger
AU  - Dunin-Borkowski, Rafal
AU  - Ebert, Philipp
TI  - Dislocation bending in GaN/step-graded (Al,Ga)N/AlN buffer layers on Si(111) investigated by STM and STEM
JO  - The philosophical magazine
VL  - 98
IS  - 34
SN  - 1478-6443
CY  - Abingdon
PB  - Taylor & Francis
M1  - FZJ-2018-07695
SP  - 3072 - 3085
PY  - 2018
AB  - The distribution and bending of dislocations in GaN/step-graded (Al,Ga)N/AlN buffer layers grown on Si(111) are investigated by cross-sectional scanning tunnelling microscopy (STM) and scanning transmission electron microscopy (STEM). We observe dislocations with -type Burgers vector intersecting the m-plane cleavage surface and having line directions bent off the [0001] growth direction toward non-polar directions. The spatial distribution of dislocations intersecting the m-plane cleavage surface indicates consecutive bending of dislocations due to strain at interfaces between subsequent lattice mismatched buffer layers and at doping junctions, reducing the density of threading dislocations at the (0001) growth front. No interface misfit dislocations, v-shaped defects, or loss of crystalline quality are observed, demonstrating the high performance of the step-graded (Al,Ga)N/AlN buffer layers on Si for relaxing the lattice constant without creating large defect concentrations.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000447813000002
DO  - DOI:10.1080/14786435.2018.1516899
UR  - https://juser.fz-juelich.de/record/858859
ER  -