Morphology measurements by AFM tapping without causing surface damage: A phase shift characterization

He，Yang1,2,3,4,5; Yan，Yongda4,5; Geng，Yanquan4,5

2023-12-01

10.1016/j.ultramic.2023.113832

Ultramicroscopy   Impact Factor & Quartile

0304-3991

1879-2723

The morphology measurement of a surface can be done by using an atomic force microscope (AFM). However, it is difficult to ensure that the measurement does not introduce any damage to the sample surface. This paper proposes that phase shift, the phase change between the original surface and scanned area, can provide a characteristic signal of the tip-surface interaction. On a poly (methyl methacrylate) thin film, the present investigation explored the relationship between phase shift and nondestructive surface morphology measurement under the tapping mode of an AFM. The study showed that when the drive amplitude was doubled, the phase shift reached from 0.47° to 1.85°. Under this condition, wrinkles became observable. With the tip radius in the range of 15–20 nm, no phase shift appeared between a scanned area and the original surface after multiple measurements. In this case, the tip-surface energy dissipation was in the range of 10–35 eV, showing a nondestructive interaction of the surface with the AFM tip. When the tip radius was about 55 nm, under the same tip excitation parameters, the energy dissipation per tap varied from 60 to 110 eV, and a phase shift occurred in the range of 0.02–0.64°, while the surface plastic deformation was still extremely minor after multiple tip scanning. A higher phase shift was occurred on the softer surface attributed to multiple scanning under tapping mode. The study found that the phase shift characteristics was a more sensible measure to signify the transition from a nondestructive to a destructive surface morphology measurement by using the tapping mode of an AFM.

AFM Phase shift Polymer Surface damage Tapping mode

SCI

English

First

National Natural Science Foundation of China[52035004];National Natural Science Foundation of China[52222512];National Natural Science Foundation of China[52293401];Shenzhen Science and Technology Innovation Program[RCBS20210706092216025];

Microscopy

Microscopy

WOS:001069799600001

ELSEVIER

CHEMISTRY

2-s2.0-85168770153

Scopus

1.Shenzhen Key Laboratory of Cross-scale Manufacturing Mechanics,Southern University of Science and Technology,Shenzhen,518055,China
2.SUSTech Institute for Manufacturing Innovation,Southern University of Science and Technology,Shenzhen,518055,China
3.Department of Mechanics and Aerospace Engineering,Southern University of Science and Technology,Shenzhen,518055,China
4.The State Key Laboratory of Robotics and Systems,Robotics Institute,Harbin Institute of Technology,Harbin,150001,China
5.Center for Precision Engineering,Harbin Institute of Technology,Harbin,150001,China

He，Yang,Yan，Yongda,Geng，Yanquan. Morphology measurements by AFM tapping without causing surface damage: A phase shift characterization[J]. Ultramicroscopy,2023,254.

He，Yang,Yan，Yongda,&Geng，Yanquan.(2023).Morphology measurements by AFM tapping without causing surface damage: A phase shift characterization.Ultramicroscopy,254.

He，Yang,et al."Morphology measurements by AFM tapping without causing surface damage: A phase shift characterization".Ultramicroscopy 254(2023).