The preparation of thin films of germanium and silicon

Laser-assisted sample preparation of silicon for high-resolution transmission electron microscopy

A sample-polishing technique was developed to provide a well-defined thin foil of Si with a clean surface down to atomic dimensions. The resulting samples permit high-resolution transmission electron microscope (HRTEM) imaging unobstructed by artifacts originating from a damaged sample. Samples were not polished by dynamic momentum transfer via accelerated ions like in ion milling; instead, valence electron excitation by photon absorption was used. HRTEM inspection showed that the foils prepared by this method were free from extrinsic lattice defects and had smooth surfaces down to atomic dimensions.

Ion Milling of Compound Semiconductors for Transmission Electron Microscopy

Serious artefactual structures can be introduced into transmission electron microscope specimens of compound semiconductors when the latter are prepared by ion milling under non-optimum conditions. In the present investigations, the nature of these artefacts is characterised and results obtained using conventional argon ion milling are compared with those obtained using alternative ion species, including iodine ions. This work demonstrates the large improvement in specimen structural quality which can be achieved by combining a logical selection of ion species with a careful choice of milling conditions.

Chemical polishing method of GaAs specimens for transmission electron microscopy

A practical method for transmission electron microscopy specimen preparation of GaAs-based materials with quantum dot structures is presented to show that high-quality image observations in high-resolution transmission electron microscopy (HRTEM) can be effectively obtained. Specimens were prepared in plan-view and cross-section using ion milling, followed by two-steps chemical fine polishing with an ammonia solution (NH(4)OH) and a dilute H(2)SO(4) solution. Measurements of electron energy loss spectroscopy (EELS) and atomic force microscopy (AFM) proved that clean and flat specimens can be obtained without chemical residues. HRTEM images show that the amorphous regions of carbon and GaAs can be significantly reduced to enhance the contrast of lattice images of GaAs-based quantum structure.