Realization and characterization of Si nanostructures

Laser interference pattering can be used to produce periodic silicon structures from amorphous silicon films. We demonstrate that periods down to 210 nm and structure sizes less than 100 nm can be realized. We examine film agglomeration as a way for direct laser pattering without etching. The capability of the method to produce different morphologies is investigated. An analytical two-dimensional thermal calculation is compared with the experimentally observed sizes to understand the physical limits of the process. As an extension of the method, an oxidation step is shown to reduce the lateral dimensions of stripes without interrupting them. The results indicate possible processes for the production of yet smaller structures and for the use of these films as etching masks.