Combined AFM methods to improve reliability investigations of thin oxides

A method is presented to combine the advantages of Conductive Atomic Force Microscopy (C-AFM) and Intermittent Contact AFM (IC- AFM) investigations on the same single area of a SiO/sub 2/ surface. A procedure is shown to overlay precisely different physical AFM images from one single measurement area, by the use of orientation marks (nano marks). Even structures of less than 0.5nm in height with lateral dimensions of a few tenth of a nanometer on a SiO/sub 2/ surface can be located and precisely scanned multiple times by various AFM techniques. With this method the results of different AFM techniques gained by use of different measurement procedures and by different probe tips can be combined to improve the significance of reliability investigations. Artefacts of the measurement procedures and the impact of probe tips may also be studied in more detail.