Atomic force microscope coupled with an optical microscope

Abstract

A compact atomic force microscope that can easily find and position the surface point to be measured has been developed. Tip spring displacement is detected using an optical sensor that detects the focusing error. The objective lens of this sensor is also used to project an optical image of the sample surface onto a CCD image sensor. A micro-step XY stage mechanism has been developed to move a sample over a wide range. When a single cosine waveform voltage is applied to a piezoelectric tube scanner, the quick bending motion causes the sample holder to progress by frictional force. This mechanism can drive the sample holder two-dimensionally in μm-order steps. Using this mechanism, the point to be measured is easily positioned. Subsequently, the sample is moved by the same tube scanner with the usual scanning mode of an atomic force microscope. This atomic force microscope is compact and stable, because no additional XY stage is necessary to position a sample.