Precision measurement method of nanometer clearance in nanostructure based on atomic force microscope

Abstract

The invention relates to a method of precision measurement of nanometer clearance of a nanometer structure based on an atomic force microscope, the method comprising: scanning the central region of a top surface of a target sample, and positioning the tip of a probe at the center of the sample; loading / unloading a vertical force with the probe of the atomic force microscope until the bottom surface of the sample contacts the substrate; and recording a force curve of the atomic force microscope during loading / unloading, so as to obtain a nanometer clearance between the bottom surface of the sample and the substrate. Specifically, the method comprises: calibrating the sensitivity of a micro cantilever of the atomic force microscope; positioning the tip of the probe of the atomic force microscope at the geometrical center of the top surface of the sample; obtaining a consistent force curve and a disjunctive force curve; comparing the slopes of the three curves including the sensitivity force curve, the consistent force curve, and the disjunctive force curve; and extracting the distance between the bottom surface of the sample and the substrate. According to the invention, measurement error due to offset of a target point from the center of a sample can be eliminated without damage on the structure of a target nanometer device, thus high-resolution measurement of nanometer clearance of nanometer structures is realized.

Description

technical field [0001] The invention relates to a measurement method for a micro / nano electromechanical system. In particular, it relates to a precision measurement method for nano-gap in nano-structures based on atomic force microscopy, which can realize non-destructive precision measurement of nano-suspension gaps in a large class of nano-structures such as nano-beams and nano-capacitance sensors based on atomic force microscope force curves. Background technique [0002] Nanoelectromechanical systems (NEMS) is an emerging technology field developed on the basis of microelectromechanical systems (MEMS), and it is also an important part of nanotechnology. Nanosuspension gaps exist in a variety of NEMS structures and devices (such as nanobeams and nanocapacitance sensors, etc.), and the precise measurement of the height of nanosuspension gaps is of great significance for evaluating the device performance and processing technology of such nanostructures. In the field of nano...

AI Technical Summary

Problems solved by technology

Since the damaged nanostructures can no longer be used, in the specific operation process, a batch of nanostructures with the same size are generally processed by the same process, and some of them are selected for this destructive nanosuspension gap height measurement. However, the same process flow does not guarantee that all the processed structures have exactly the same size characteristics, so this method often cannot actually obtain the true height of the nano-suspension gap of the target structure to be tested.

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