https://doi.org/10.1051/epjap:2004116
Light induced contrast in Kelvin Force Microscopy of GaN epilayers
Institute of Experimental Physics, Warsaw University, Hoza 69,
00-681 Warsaw, Poland
Corresponding author: Rafal.Bozek@fuw.edu.pl
Received:
4
July
2003
Accepted:
9
December
2003
Published online: 15 July 2004
The results of investigations of undoped GaN heteroepitaxial layers with Atomic Force Microscopy and Kelvin Force Microscopy are presented. The measurements of surface potential were performed in the dark and under illumination below and above the energy gap of GaN. In the dark no fluctuations of potential were observed. Moderate illumination revealed fluctuations of (1) short range (~ 100 nm and ~ 0.1 V), related to threading dislocations with a screw component and (2) long range, independent of morphology (~ 5 µm and ~ 0.3 V). Intense illumination removed long range fluctuations, while dislocations remained surrounded by areas of lower potential.
PACS: 68.37.-d – Microscopy of surfaces, interfaces, and thin films / 07.79.-v – Scanning probe microscopes and components / 61.72.Hh – Indirect evidence of dislocations and other defects (resistivity, slip, creep, strains, internal friction, EPR, NMR, etc.)
© EDP Sciences, 2004
