Design of target profilometer based on AFM and its measure precision analysis

A target profilometer based on commercial atomic force microscope (AFM) was developed, and its precision rotary shafting was designed. In order to evaluate the measurement uncertainty, the rotary precision of air bearing was tested and the error curve of the spindle was obtained with the least square roundness error of about 48 nm. The noise in AFM measurement process was tested after the shafting was assembled. The amplitude of static noise dropped to about 10 nm though structural modification. The system was utilized in the measurement of circular traces on the target surface, which got the noise amplitude of about 13 nm and the composite measure error of about 49.7 nm during the running process. In addition, the accuracy of the system can be further improved by error separation technique.