Strategies of Molecular Construction

Molecular construction is a branch of synthetic chemistry. It differs in two aspects from traditional synthetic approaches. In a single molecule (and not just in the crystal), both the specified binding topology and molecular geometry should be preserved. Another point is that the macromolecular units are defined by molecular weight and structure and exhibit specific binding groups that in subsequent construction steps serve as binding sites. As long as there are no autonomous nanosystems, the...

Size Reduction by Sidewall Transfer

The line width of lithographic features can be drastically reduced if side wall depositions at perpendicularly etched micro- or nanostructures are used as masks in subsequent anisotropic etching or deposition processes. This technique transfers the side-wall topology rather than the original structure to the substrate. It is therefore named sidewall transfer lithography STL . The application of STL to silicon leads to the formation of sub-10-nm structures. The process involves the deposition of...

Nanoswitches Molecular Switches and Logic Elements

Switching processes can be supported by electronic, mechanical or material changes. When approaching the dimensions of single molecules, the borders between these three principles disappear. Molecular movements are linked to electronic processes, and on the other hand, electronic transfers lead to, at least temporarily, changes in the chemical structure. Nanomechanical and nanoelectronic systems with free-standing functional structures can be realized by a combination of FIB and CVD...