Ultrastable atomic force microscopy: atomic-scale stability and registration in ambient conditions.
Instrumental drift in atomic force microscopy (AFM) remains a critical, largely unaddressed issue that limits tip-sample stability, registration, and the signal-to-noise ratio during imaging. By scattering a laser off the apex of a commercial AFM tip, we locally measured and thereby actively controlled its three-dimensional position above a sample surface to <40 pm (Deltaf = 0.01-10 Hz) in air at room temperature. With this enhanced stability, we overcame the traditional need to scan rapidly while imaging and achieved a 5-fold increase in the image signal-to-noise ratio. Finally, we demonstrated atomic-scale ( approximately 100 pm) tip-sample stability and registration over tens of minutes with a series of AFM images on transparent substrates. The stabilization technique requires low laser power (<1 mW), imparts a minimal perturbation upon the cantilever, and is independent of the tip-sample interaction. This work extends atomic-scale tip-sample control, previously restricted to cryogenic temperatures and ultrahigh vacuum, to a wide range of perturbative operating environments.
JILA, National Institute of Standards and Technology, and University of Colorado, Boulder, Colorado 80309, USA.
Gavin M
GM
King
Ashley R
AR
Carter
Allison B
AB
Churnside
Louisa S
LS
Eberle
Thomas T
TT
Perkins
D003080:Cold Temperature; D018625:Microscopy, Atomic Force / Q000379:methods*; D014618:Vacuum