Real-Time Estimation of the Tip-Sample Interactions in Tapping Mode Atomic Force Microscopy with a Regularized Kalman Filter

The real-time and accurate measurement of tip-sample interaction forces in Tapping Mode Atomic Force Microscopy (TM-AFM) is a remaining challenge. This obstruction fundamentally stems from the causality of the physical systems. Since the input of the dynamic systems propagates to the output with some delay, and multiple different inputs can...

A comprehensive model for transient behavior of tapping mode atomic force microscope

Many investigations have focused on steady-state nonlinear dynamics of cantilevers in tapping mode atomic force microscopy (TM-AFM). However, a transient dynamic model?which is essential for a model-based control design?is still missing. In this paper, we derive a mathematical model which covers both the transient and steady-state behavior. The...

Improved sub-surface AFM using photothermal excitation

In this paper, we present an AFM based subsurface measurement technique that can be used for overlay and critical dimensions (CD) measurements through optically opaque layers. The proposed method uses the surface elasticity map to resolve the presence and geometry of subsurface structures. To improve the imaging performance of the AFM based...

Improved sub-surface AFM using photothermal excitation

Sub-surface Imaging with Photo Thermal Actuation

In the semiconductor industry, the need for characterization of subsurface features of wafers on a sub-nanometer level becomes ever more important. With Scanning Subsurface Probe Microscopy (SSPM), the smallest features can be measured with high resolution.

Frequency Modulation Sub-surface Atomic Force Microscopy

Elasticity based Sub- surface Atomic Force Microscopy is a promising metrology solution for CD measurements, defect characterization and alignment and overlay applications.

On the origin of amplitude reduction mechanism in tapping mode atomic force microscopy

The origin of amplitude reduction in Tapping Mode Atomic Force Microscopy (TM-AFM) is typically attributed to the shift in resonance frequency of the cantilever due to the nonlinear tip-sample interactions. In this paper, we present a different insight into the same problem which, besides explaining the amplitude reduction mechanism, provides a...

Chaos: the speed limiting phenomenon in dynamic atomic force microscopy

This paper investigates the closed-loop dynamics of the Tapping Mode Atomic Force Microscopy using a new mathematical model based on the averaging method in Cartesian coordinates. Experimental and numerical observations show that the emergence of chaos in conventional tapping mode AFM strictly limits the imaging speed. We show that, if the...

Minimizing tip-sample forces and enhancing sensitivity in atomic force microscopy with dynamically compliant cantilevers

Due to the harmonic motion of the cantilever in Tapping Mode Atomic Force Microscopy, it is seemingly impossible to estimate the tip-sample interactions from the motion of the cantilever. Not directly observing the interaction force, it is possible to damage the surface or the tip by applying an excessive mechanical load. The tip-sample...

Transient Tip-Sample Interactions in High-Speed AFM Imaging of 3D nano structures

The maximum amount of repulsive force applied to the surface plays a very important role in damage of tip or sample in Atomic Force Microscopy(AFM). So far, many investigations have focused on peak repulsive forces in tapping mode AFM in steady state conditions. However, it is known that AFM could be more damaging in transient conditions. In...