Papers by Keyword: C-AFM

Abstract: The aim of this work is to study the effect of Ge introduction during the nucleation step on the SiC growth on 4H-SiC on-axis substrate. After 10 minutes surface pretreatment at 1500°C under C₃H₈ or GeH₄, the grown 3C layer at the same temperature can switch from highly twinned (C₃H₈) to almost twin-free single domain (GeH₄). However, for too low and too high GeH₄ fluxes, the layers display a mixture of polytype. Keeping the best pretreatment but varying the growth temperature degrades the morphology and changes the polytype of the layer. Preliminary electrical results using C-AFM on the 3C-SiC layer are also presented.

Abstract: Both a low and a high resistance stateｓ which were written by the voltage application in a local region of NiO/Pt films by using conducting atomic force microscopy (C-AFM) were observed by using scanning electron microscope (SEM) and electron probe micro analysis (EPMA). The writing regions are distinguishable as dark areas in a secondary electron image and thus can be specified without using complicated sample fabrication process to narrow down the writing regions such as the photolithography technique. In addition, the writing regions were analyzed by using energy dispersive X-ray spectroscopy (EDS) mapping. No difference between the inside and outside of the writing regions is observed for all the mapped elements including C and Rh. Here, C and Rh are the most probable candidates for contamination which affect the secondary electron image. Therefore, our results suggested that the observed change in the contrast of the secondary electron image is related to the intrinsic change in the electronic state of the NiO film and a secondary electron yield is correlated to the physical properties of the film.

Abstract: Aluminum doped ZnO thin films were synthesized by the water-mist assisted spray pyrolysis technique. The structural characterization by means of X-Ray diffraction measurements is reported. By means of Atomic Force Microscopy, the superficial electrical characteristics of the thin films are studied. Specifically, contact current images are shown and discussed. It is important to emphasize that in spite of no voltage is applied to the Atomic Force Microscopy contact conductive tip, current images are getting.

Abstract: In this work, the electrical properties of Pt/GaN Schottky contacts were studied. The temperature dependence of the barrier height and ideality factor, and the low experimental value of the Richardson’s constant, were discussed considering the formation of an inhomogenous Schottky barrier. Local current-voltage measurements on Pt/GaN contact, performed with a conductive atomic force microscope, demonstrated a Gaussian distribution of the local barrier height values and allowed to monitor the degree of inhomogeneity of the barrier. The presence of defects, terminating on the bare GaN surface, was correlated with the electrical behavior of the inhomogeneous barrier.