Method for stimulating probe to vibrate in atomic force microscope

Abstract

The invention provides a method for stimulating a probe to vibrate in an atomic force microscope. A piezoelectric transducer is arranged below the probe; the piezoelectric transducer generates mechanical vibration in the vertical direction under the action of a signal source; and the probe is vibrated under the stimulation of mechanical vibration waves. Compared with an existing method for stimulating a cantilever to vibrate by adopting a probe driver so as to drive the probe to vibrate, the method has the advantages that the tip of the probe can more easily get rid of the action of adhesion force and capillary force on the surface of a sample to vibrate stably, so that stable scanning imaging is facilitated, a high-resolution scanning image is obtained, and the high-performance requirement on the cantilever is reduced.

Description

technical field [0001] The invention relates to the technical field of atomic force microscopes, in particular to a method for exciting probe vibration in atomic force microscopes. Background technique [0002] Atomic Force Microscope (AFM) is a new instrument with atomic-level high resolution invented after Scanning Tunneling Microscope (STM). It has been widely used in semiconductors, nano functional materials, biology, chemical industry, food, pharmaceutical research and research experiments of various nano-related subjects in scientific research institutes. Become an essential tool for nanoscience research. [0003] In the atomic force microscope, a nanometer-scale probe is fixed on a sensitively manipulated micron-scale elastic cantilever. When the probe is close to the sample, the force between the atoms at the top and the surface atoms of the sample will bend the cantilever and deviate from the original Location. By reconstructing the three-dimensional image accord...

AI Technical Summary

Problems solved by technology

Since the driving force only acts on the root of the cantilever, when the probe tip scans the sample, the adhesive force and capillary force on the sample surface will generate a downward suction force on the tip, thereby inhibiting the probe oscillation and causing the probe oscillation amplitude Decrease, or even drop to zero, and then affect the scanning imaging, resulting in imaging failure

[0009] To avoid this situation, the cantilever is usually required to have a high elastic constant (20-60N / m), resonance frequency and large driving force, but this will increase the equipment requirements, and at the same time cause damage to the sample during imaging in tapping mode The original structure of the sample, especially for soft samples, such as suspended graphene sheets, gel-like samples, etc., may also damage or move the sample, and contaminate the tip, increasing the contact area between the tip and the sample, making stable high-resolution Imaging becomes more difficult

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