Large lateral contact stiffness on Si nanopillar surfaces

Y Ishii,R Yanagisawa,K Miura,M Nomura,N Watanabe,N Sasaki

doi:10.1063/5.0082255

Abstract

We studied the lateral contact stiffness (kcontactx) between the tip of a frictional force microscope and a pillar surface to identify the sliding behavior of the tip at the submicrometer scale. The kcontactx and mean lateral force (⟨F⟩) were systematically measured as functions of pillar diameter φ. We found that the kcontactx on a single Si pillar surface increased whereas the ⟨F⟩ rapidly decreased as φ decreased from the micrometer to the nanometer scale. This contradiction could be explained by the change in tip behavior from dynamic sliding to static sticking.

Highlights

Frictional force microscopy (FFM) is an important tool for studying atomic-scale friction, adhesion, lubrication, and wear.1 this technique is not always able to provide correct information on frictional behaviors when the mechanical stiffness of the sample material changes,2 because of corresponding changes in the contact mechanics between the instrument tip and sample
FFM is used to measure the lateral force and contact stiffness on a single Si pillar surface as a complementary technique to understand the change in contact mechanics between the tip and pillar surface as a function of the Si pillar size
⟨F⟩ ≅ 10 pN and kxcontact = 3.79 N/m when φ = 70 nm represents the “static” frictional behavior. These observations indicate that the tip behavior changes from dynamic sliding to static sticking when the pillar diameter decreases from the micrometer to the nanometer scale

Summary

INTRODUCTION

Frictional force microscopy (FFM) is an important tool for studying atomic-scale friction, adhesion, lubrication, and wear. this technique is not always able to provide correct information on frictional behaviors when the mechanical stiffness of the sample material changes, because of corresponding changes in the contact mechanics between the instrument tip and sample. Frictional force microscopy (FFM) is an important tool for studying atomic-scale friction, adhesion, lubrication, and wear.. Frictional force microscopy (FFM) is an important tool for studying atomic-scale friction, adhesion, lubrication, and wear.1 This technique is not always able to provide correct information on frictional behaviors when the mechanical stiffness of the sample material changes, because of corresponding changes in the contact mechanics between the instrument tip and sample. When the static friction between the tip and sample is small, only the dynamic friction can be measured in the scan region. FFM is used to measure the lateral force and contact stiffness on a single Si pillar surface as a complementary technique to understand the change in contact mechanics between the tip and pillar surface as a function of the Si pillar size Strong elastic softening in silicon nanotubes has been observed by other groups. In this paper, FFM is used to measure the lateral force and contact stiffness on a single Si pillar surface as a complementary technique to understand the change in contact mechanics between the tip and pillar surface as a function of the Si pillar size

EXPERIMENTAL

RESULTS AND DISCUSSION

CONCLUSIONS

Conflict of Interest