We have investigated the morphology and structure of dolomite MgCa(CO(3))(2)(104) surfaces by bimodal dynamic force microscopy with flexural and torsional resonance modes in ultra-high vacuum at room temperature. We found that the surface slowly decomposes by degassing CO(2) in a vacuum and becomes covered by amorphous clusters, presumably MgO and CaO. By choosing an optimal sample preparation procedure (i.e. cleaving in a vacuum and mild annealing for stabilizing clusters for a short time), atomically clean surfaces were obtained. The complex tip-sample interaction, arising from carbonate groups and Mg and Ca atoms of the surface, induces a large variety of atomic-scale imaging features.

No abstract

The shielding cell architecture of a buried grid (BG) Junction Barrier Schottky (JBS) diode consisting of multiple consecutive p+-implanted stripes below the metal/semiconductor interface has been observed by performing non-contact Scanning Probe Microscopy (SPM) and Secondary Electron Potential Contrast (SEPC) measurements on the cross-section of the device. We have demonstrated that these techniques succeeded in mapping the two-dimensional carrier distribution inside the active area of the device, however with different resolution and quantification possibilities.

No abstract

Electronically active dopant profiles of epitaxially grownn-type 4H-SiC calibration layer structures with concentrations ranging from 3.1015cm-3to 1·1019cm-3have been investigated by non-contact Scanning Probe Microscopy (SPM) methods. We have shown that Kelvin Probe Force Microscopy (KPFM) and Electrostatic Force Microscopy (EFM) are capable of resolving two-dimensional carrier maps in the low doping concentration regime with nanoscale spatial resolution. Furthermore, different information depths of this wide band gap semiconductor material could be assessed due to the inherent properties of each profiling method. We additionally observed a resolution enhancement under laser illumination which we explain by reduced band-bending conditions. To gauge our SPM signals, we utilized epitaxially grown layers which were calibrated, in terms of dopant concentration, byC-Vmeasurements.