COMPOSITE SCANNING TUNNELLING MICROSCOPE WITH A POSITIONING FUNCTION

This invention relates to a scanning tunnelling microscope which has a mechanism which accurately guides the needle of the STM to a portion the position of which has been determined by another calibrating means. In the invention, a standard sample for positioning is observed under an optical microscope or SEM, then the same sample is observed under the STM and the positional relationship between the optical axis and the STM needle is determined from the two images. In such circumstances, because the scanning region of the STM is 10 to 12.mu. at most, it is necessary to have a standard sample with specific properties such that the position within this picture frame is recognizable. Here, we relate to a device which incorporates such a standard sample, determines the positional relationship between the two (the distance between the optical axis and the STM needle), compensates for this distance alone and makes it possible to observe the same point with both devices.