Advances in the manufacture of integrated circuits, x?ray optics, magnetic read-write heads, optical data storage media, and razor blades require advances in ultraprecision metrology. Each of these industries is currently investigating the use of atomic force microscopy (AFM) to improve the precision and accuracy of their manufacturing process control. To facilitate the use of AFMs for manufacturing we have developed an AFM capable of making accurate dimensional measurements. We call this system the calibrated AFM (C?AFM). The C?AFM has been constructed as much as possible out of commercially available components. We use a flexure stage driven by piezoelectric transducers for scanning, a heterodyne interferometer to measure the X and Y displacements of the sample, a capacitance sensor to measure the Z displacement of the sample, and a commercially available AFM control system. The control system has two feedback loops which read from the X and Y interferometers, respectively, and adjust the piezoelectric voltages to keep the X?Y scan position accurate. The critical electromechanical and metrology issues involved in the construction and operation of such a system will be discussed in detail.
Citation: Journal of Vacuum Science and Technology B
Pub Type: Journals