Littérature scientifique sur le sujet « Nanoscale Hetero-junctions »

This paper presents a macro-and nanoscale electrical investigation of Schottky and metal-oxide junctions with hetero-epitaxial 3C-SiC layers grown on Si. Statistical current-density-voltage (J-V) characterization of Pt/3C-SiC Schottky diodes showed an increase of the reverse leakage current with increasing the devices diameters. Furthermore, C-V and J-V analyses of SiO2/3C-SiC capacitors revealed non-idealities of the thermal oxide, such as a high trapped positive charge (3×1012 cm−2) and a reduced breakdown field (EBD=6.5 MV/cm) compared to ideal SiO2. Nanoscale electrical characterizations by conductive atomic force microscopy (CAFM) and scanning capacitance microscopy (SCM) allowed to shed light on the origin of non-ideal behavior of Schottky and thermal oxide junctions, by correlating the morphological features associated to 3C-SiC crystalline defects with local current transport and carrier density.

The development of applied aspects of the phenomenon of self - organization in solving the problem of improving the efficiency of solar converters is considered. It is proved that the creation of self -organized nano - sized semiconductor thermal contacts on t he surface of a solar cell can significantly improve the process of converting solar radiation into electricity . It is shown that such an improvement is carried out regardless of the degree of crystallinity of the substrate material. This makes it possible to use cheap and stably stable technical silicon as a substrate for solar cells, on the surface of which many nanoscale p - n junctions from another semiconductor material are created. It is proved that due to the manifestation of the physical effect of sel f - organization, almost ideal hetero structures with high crystal perfection and high uniformity are realized. The paper defines the cond itions under which contacting semiconductors will be able to form stable and photo - efficient hetero junctions. Keywords:semiconductor, the current - voltage characteristic of nanocluster

ABSTRACTThe carbon nanotubes and carbon nanobtube junctions have recently emerged as excellent candidates for use as the building blocks in the formation of nanoscale electronic devices. Single wall carbon nanotubes, as molecular wires, could be used as nanoscale interconnects, where as complex junctions of nanotubes of different chirality can be used as rectifying and transiting devices. It has been shown that pentagon-heptagon defect is responsible for the creation of simple hetero-junctions. Complex junctions, such as 3-termianl T-junctions and Y-junctions require entirely different arrangement of defects. These 3-terminal junctions form prototypes of nanoscale tunnel devices made entirely of carbon. Furthermore, either n-type or p-type doping of the semiconducting portion of these complex junctions should yield Schottky barrier type devices. We also investigate simple wires and junctions of boron and nitrogen (III-V elements) and compare with those of carbon. The structural and electronic properties on nanotubes and nanotube junctions (carbon as well as BN) are studied using a generalized tight-binding molecular dynamics (GTBMD) scheme.

ABSTRACTInterfaces, contacts, and homo- or hetero-junctions are critical components in nanometer dynamic random access memory (DRAM) semiconductor devices. With shrinkage in device dimensions, interfacial analysis by TEM becomes more and more challenging, especially in the case of investigating failure mechanisms for nanoscale FRACTURED INTERFACES where electronic signatures found to be open. In this article, fractured interfaces at several C1-type contacts (a path between a Bitline and a Metal 1 interconnector) in a deep-subquarter-micron 256Mbit DRAM device were investigated by a JEOL 2010F analytical transmission electron microscope (TEM) with field-emission gun (FEG) running at 200KV. Considering the difficulty to exactly focus the fractured nano-scale interfaces at sufficiently high magnifications, high-resolution TEM (HR-TEM) and analytical scanning transmission electron microscopy (STEM) coupled with x-ray energy dispersive spectroscopy (XEDS) elemental linescan techniques were employed to provide supplemental information from difference prospects. An in-depth understanding for the nanoscale interfacial fracture mechanisms was established, and a simple model is initiated accordingly.