The Sensitivity of Subsurface Contact Resonance Atomic Force Microscopy to Changes in the Depth of Buried Features: a Nonlinear Approach

This work presents data confirming the existence of a scan speed related phenomenon in contact-mode atomic force microscopy (AFM). Specifically, contact-resonance spectroscopy is used to interrogate this phenomenon. Above a critical scan speed, a monotonic decrease in the recorded contact-resonance frequency is observed with increasing scan speed. Proper characterization and understanding of this phenomenon is necessary to conduct accurate quantitative imaging using contact-resonance AFM, and other contact-mode AFM techniques, at higher scan speeds. A squeeze film hydrodynamic theory is proposed to explain this phenomenon, and model predictions are compared against the experimental data.

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Hydrodynamic corrections to contact resonance atomic force microscopy measurements of viscoelastic loss tangent

Review of Scientific Instruments ◽

10.1063/1.4812633 ◽

2013 ◽

Vol 84 (7) ◽

pp. 073703 ◽

Cited By ~ 11

Author(s):

Ryan C. Tung ◽

Jason P. Killgore ◽

Donna C. Hurley

Keyword(s):

Atomic Force Microscopy ◽

Loss Tangent ◽

Force Microscopy ◽

Atomic Force ◽

Contact Resonance

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A Plate-Like Sensor for the Identification of Sample Viscoelastic Properties Using Contact Resonance Atomic Force Microscopy

ASME Letters in Dynamic Systems and Control ◽

10.1115/1.4049538 ◽

2021 ◽

pp. 1-9

Author(s):

Matteo Aureli ◽

Ryan Tung

Keyword(s):

Atomic Force Microscopy ◽

Viscoelastic Properties ◽

Ritz Method ◽

Theoretical Derivation ◽

Force Microscopy ◽

Atomic Force ◽

Modal Damping ◽

Stiffness And Damping ◽

Data Estimation ◽

Contact Resonance

Abstract In this paper, we present a new contact resonance atomic force microscopy based method utilizing a square, plate-like microsensor to accurately estimate viscoelastic sample properties. A theoretical derivation, based on Rayleigh-Ritz method and on an “unconventional” generalized eigenvalue problem, is presented and a numerical experiment is devised to verify the method. We present an updated sensitivity criterion that allows users, given a set of measured in-contact eigenfrequencies and modal damping ratios, to select the best eigenfrequency for accurate data estimation. The verification results are then presented and discussed. Results show that the proposed method performs extremely well in the identification of viscoelastic properties over broad ranges of non-dimensional sample stiffness and damping values.

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Subsurface imaging of flexible circuits via contact resonance atomic force microscopy

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.10.159 ◽

2019 ◽

Vol 10 ◽

pp. 1636-1647 ◽

Cited By ~ 5

Author(s):

Wenting Wang ◽

Chengfu Ma ◽

Yuhang Chen ◽

Lei Zheng ◽

Huarong Liu ◽

...

Keyword(s):

Atomic Force Microscopy ◽

Theoretical Calculations ◽

Contact Stiffness ◽

Metal Layer ◽

Experimental Results ◽

Subsurface Imaging ◽

Force Microscopy ◽

Atomic Force ◽

Cover Thickness ◽

Contact Resonance

Subsurface imaging of Au circuit structures embedded in poly(methyl methacrylate) (PMMA) thin films with a cover thickness ranging from 52 to 653 nm was carried out by using contact resonance atomic force microscopy (CR-AFM). The mechanical difference of the embedded metal layer leads to an obvious CR-AFM frequency shift and therefore its unambiguous differentiation from the polymer matrix. The contact stiffness contrast, determined from the tracked frequency images, was employed for quantitative evaluation. The influence of various parameter settings and sample properties was systematically investigated by combining experimental results with theoretical analysis from finite element simulations. The results show that imaging with a softer cantilever and a lower eigenmode will improve the subsurface contrast. The experimental results and theoretical calculations provide a guide to optimizing parameter settings for the nondestructive diagnosis of flexible circuits. Defect detection of the embedded circuit pattern was also carried out, which indicates the capability of imaging tiny subsurface structures smaller than 100 nm by using CR-AFM.

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