Quantitative scanning probe microscope topographies by charge linearization of the vertical actuator

Area of Science:

• Materials Science
• Nanotechnology
• Physics

Background:

• Scanning probe microscopy (SPM) techniques like atomic force microscopy (AFM) and scanning tunneling microscopy (STM) rely on piezoelectric actuators to control probe-sample distance.
• Accurate topography reconstruction in SPM is crucial for nanoscale imaging and analysis.
• Piezoelectric actuators, essential for vertical positioning, suffer from hysteresis, introducing significant errors in topographic measurements.

Purpose of the Study:

• To address the challenge of piezoelectric actuator hysteresis in scanning probe microscopy.
• To develop and implement a method for linearizing vertical piezoelectric actuator response.
• To quantify the reduction in topographic uncertainty achieved by the proposed method.

Main Methods:

• Utilized a charge drive system to control the vertical piezoelectric actuator.
• Implemented the charge drive to linearize the actuator's displacement response.
• Compared topographic data obtained with the charge drive against conventional voltage-driven methods.

Main Results:

• The piezoelectric actuator's response was significantly linearized using the charge drive.
• Topographic uncertainty was reduced from a maximum of 14% to 0.65%.
• Demonstrated a substantial improvement in the accuracy of sample topography reconstruction.

Conclusions:

• A charge drive is an effective method for mitigating piezoelectric actuator hysteresis in SPM.
• This technique substantially enhances the precision of topographic measurements in AFM and STM.
• The improved accuracy facilitates more reliable nanoscale imaging and material characterization.