Tapping type high-sensitivity SPM feeler based on PVDF and measurement method

Abstract

The invention relates to a PVDF-based tapping-mode high-sensitivity SPM measuring head and a measuring method thereof. The PVDF-based tapping-mode high-sensitivity SPM measuring head is characterized in that a PVDF piezoelectric membrane is taken as a vibrating beam and a tungsten probe is taken as scanning probe; the vibrating beam is set to be a simply supported beam with bended radian; the left end and the right end of the vibrating beam are fixed on front ends of oppositely arranged piezoelectric drivers on both sides through clamping structures respectively; rear ends of the piezoelectric drivers on both sides are fixed on respective cantilever beams respectively; one end of each of the cantilever beams is suspended on a measuring head holder; and the scanning probe is fixed on a center position on the lower surface of the vibrating beam. The measuring method takes the variation of electric charges outputted by the vibrating beam to represent the amplitude variation of the vibrating beam caused by a micrometering force, and performs multipoint micrometering force tapping scanning on a surface to be measured to realize measurement of the surface of a sample. The PVDF-based tapping-mode high-sensitivity SPM measuring head and the measuring method can realize high spatial resolution and low measuring force, are suitable for various materials, and can measure under air environment.

Description

technical field [0001] The invention relates to a nanometer measurement device, more specifically a measuring head that can be used to form a scanning probe microscope system, so that the system can realize the feedback control of the nanometer resolution in the vertical direction in the measurement of the nanometer microscopic shape; it can form a micro-nano three-dimensional The nano-positioning probe of the coordinate measuring machine realizes the nano-positioning of the probe of the three-coordinate measuring machine; it can be used to form a scanning probe microscope system to realize the surface characteristics of soft and fragile samples (such as the surface of biological materials such as protein molecules) and steep steps Samples (such as semiconductor silicon micro-devices, micro-electro-mechanical devices, etc.) for non-destructive micro-surface topography measurement at nanoscale resolution; Measurement of micromechanical parts. Background technique [0002] In...

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Problems solved by technology

[0003] The commonly used stylus profiler is a simple and reliable precision measuring instrument widely used in mechanical surface measurement. Its measurement range can reach tens of millimeters, but its vertical resolution can only reach tens of nanometers, and the measurement process The middle stylus is in continuous contact with the surface to be measured, and the lateral force is large, which is easy to cause scratches on the surface. It is not suitable for the measurement of soft materials and surfaces with steep microstructures.

Although optical measurement systems such as confocal microscopes have the advantage of non-contact measurement, and their highest vertical resolution is close to 10 nanometers, their lateral resolution cannot be improved due to the limitation of the focus spot diameter, and they are not suitable for non-reflective materials Measurement

Although the scanning tunneling microscope (STM) has the advantages of sub-nanometer vertical resolution and non-contact measurement, it cannot be directly applied to insulating materials and materials whose surface is easily oxidized because the measurement current is greatly affected by the conductivity of the measured material. There are also high requirements for the vacuum degree of the measurement environment, so its application range is greatly limited

Although the atomic force microscope (AFM) is suitable for the measurement of various materials and parameters, and has sub-nanometer vertical resolution and nN-level measurement force, most of the probes used are silicon micro-cantilever type, and its effective length Short, tip curvature radius is large, and the cone angle is usually about 30°, which is not suitable for the measurement of large-step microscopic surfaces, and the control of the silicon cantilever used in the probe needs to be realized by additional position detection systems such as optical lever method or optical interference method. , the leaked light generated by the optical detection system not only affects the measurement of the electrical parameters of the semiconductor device, but may also bring interference errors to the surface measurement

Therefore, the structure is complex and difficult to achieve adjustment and detection

Therefore, the existing surface topography measurement system does not have the universality of using

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