Method and apparatus of using peak force tapping mode to measure physical properties of a sample

摘要

Methods and apparatuses are provided for automatically controlling and stabilizing aspects of a scanning probe microscope (SPM), such as an atomic force microscope (AFM), using Peak Force Tapping (PFT) Mode. In an embodiment, a controller automatically controls periodic motion of a probe relative to a sample in response to a substantially instantaneous force determined and automatically controls a gain in a feedback loop. A gain control circuit automatically tunes a gain based on separation distances between a probe and a sample to facilitate stability. Accordingly, instability onset is quickly and accurately determined during scanning, thereby eliminating the need of expert user tuning of gains during operation.

主权项

1. A method of operating a scanning probe microscope (SPM) comprising:
generating relative substantially periodic motion between a probe and a sample; detecting the motion of the probe; recovering, from the detected probe motion, a property of the motion as the probe and sample interact in Peak Force Tapping (PFT) Mode; determining a time zone of interest associated with the property of the motion; generating an excitation signal between the probe and the sample; and measuring a response of the probe to the excitation signal generating step in the time zone of interest within a period of the interaction between the probe and the sample.