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Characterization of InAs dots on n‐GaAs by AFM with a conductive tip
Author(s) -
Takahashi T.,
Kawamukai T.,
Kamiya I.
Publication year - 1999
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/(sici)1096-9918(199905/06)27:5/6<547::aid-sia481>3.0.co;2-q
Subject(s) - wetting layer , wetting , layer (electronics) , electrical conductor , materials science , conductive atomic force microscopy , atomic force microscopy , optoelectronics , voltage , nanotechnology , composite material , electrical engineering , engineering
We performed atomic force microscopy (AFM) on anInAs‐covered GaAs surface on which InAs dot structures areformed surrounded by a wetting layer. In order to characterize itssurface band structures, we applied an a.c. bias voltage ( f =25 kHz) between a conductive AFM tip and a sample. Bymeans of a lock‐in detection technique, clear electrostaticforce images as well as topographic images were obtained with highresolution. The electrostatic force images of the different frequencycomponents ( f and 2 f ) reveal that the gapwidth between the tip and the conductive region of the sample ismodulated very little by the bias voltage in the dot‐coveredarea, whereas the gap width is obviously modulated in the wettinglayer area. These results indicate that the surface depletion is moresuppressed in the dot‐covered area than in the wetting layerarea. Copyright © 1999 John Wiley & Sons, Ltd.