Low temperature multimode atomic force microscopy using an active MEMS cantilever

Area of Science:

• Surface Science
• Nanotechnology
• Microelectromechanical Systems (MEMS)

Background:

• High-resolution atomic force microscopy (AFM) typically uses qPlus tuning fork sensors under ultra-high vacuum and low temperatures.
• qPlus sensors are favored for atomic resolution due to self-sensing, high stiffness, and large Q factor.

Purpose of the Study:

• To demonstrate a proof of concept for an active MEMS microcantilever with integrated piezoelectric sensing.
• To evaluate its capability for scanning tunneling microscopy (STM) and high-resolution non-contact AFM.

Main Methods:

• Fabrication of an active MEMS microcantilever with integrated piezoelectric sensing.
• Functionalization with a focused ion beam deposited tungsten tip.
• Imaging an atomically flat Au(111) surface using STM and non-contact AFM.

Main Results:

• The active MEMS cantilever successfully obtained high-resolution STM and non-contact AFM images.
• High contrast images were achieved on an Au(111) surface.
• Imaging was demonstrated at both the fundamental and higher eigenmodes of the cantilever.

Conclusions:

• The active MEMS microcantilever with piezoelectric sensing is a viable alternative for high-resolution surface imaging.
• This technology enables high-contrast STM and AFM imaging, expanding the toolkit for nanoscale surface analysis.