An ultrahigh vacuum fast-scanning and variable temperature scanning tunneling microscope for large scale imaging

Area of Science:

• Surface Science
• Materials Science
• Nanotechnology

Background:

• Scanning tunneling microscopy (STM) is crucial for atomic-scale surface analysis.
• Variable temperature and in-situ preparation capabilities enhance STM utility.
• Achieving high resolution and large scan areas at variable temperatures presents engineering challenges.

Purpose of the Study:

• To present the design and performance of a novel fast-scanning, variable temperature STM.
• To demonstrate its capability for large-scale, atomically resolved imaging of metallic surfaces.
• To enable in-situ sample preparation and analysis within a single instrument.

Main Methods:

• Development of an ultrahigh vacuum (UHV) STM system with a temperature range of 80–700 K.
• Integration of an efficient in-vacuum vibration isolation and cryogenic system.
• Design of a specialized sample holder and STM head for pre- and post-preparation imaging.

Main Results:

• Routine achievement of large-scale atomically resolved imaging of compact metallic surfaces.
• Refractory metal samples annealed up to 2000 K with a 15-minute cooldown from room temperature to 80 K.
• Vertical resolution of approximately 2 pm at room temperature and a scanning area of 8 x 8 µm².

Conclusions:

• The developed STM system provides a powerful tool for surface science research requiring variable temperatures and in-situ capabilities.
• The instrument's performance, including resolution and scanning speed, is suitable for detailed surface characterization.
• The design facilitates correlative studies by allowing imaging of the same sample area before and after preparation.