SCANNING FORCE MICROSCOPY OF SEMICONDUCTOR-MATERIALS AND DEVICES

Tip microscopy techniques have become very widely spread methods of sc anning imaging of microstructures or nanostructures in almost any mate rial problem. This applies both to scanning tunnelling microscopy and to scanning force microscopy (SFM). By SFM a specimen can be examined without the necessity of extensive sample preparation, allowing fast r esponse of the microscopist to technological problems. Whereas SFM in its usual axial force mode is mainly used to image topography of the s ampled surface or the distribution of surface atoms, newly developed t echniques deliver more relevant information with respect to semiconduc tor properties. Various modifications may be carried out easily to det ermine electrical or electronical microfeatures. In this sense, imagin g of internal potential distributions or of specimen internal waveform s can be achieved by determining electrostatically acting forces; usin g a metallized tip with an appropriate work function, local conductivi ty measurements can be carried out. The correlation of such electrical or electronical properties to the sample topography can be done by si multaneous recording of its topography. Here it has become obvious tha t lateral force imaging gives more detailed information than the more common axial mode.