Low-temperature UHV scanning tunneling microscope double sample holder for in situ exchangeable clean room processed...

Area of Science:

• Materials Science
• Surface Science
• Nanotechnology

Background:

• Scanning Tunneling Microscopy (STM) requires pristine tip apexes for atomic resolution.
• Preparing and maintaining tip quality in ultra-high vacuum (UHV) environments is challenging.
• Integrating diverse sample types within a single UHV system necessitates advanced sample handling.

Purpose of the Study:

• To present a generalized double sample holder (DSH) for multi-probe low-temperature UHV STM.
• To enable in situ tip apex preparation on a reference sample within the DSH.
• To demonstrate high-resolution imaging of nanotechnology-fabricated samples from clean room environments.

Main Methods:

• Development of a generalized double sample holder (DSH) for UHV LT STM.
• In situ mounting and dismounting of ancillary sample holders within the DSH.
• Utilizing a UHV scanning electron microscope for STM tip navigation and sample observation.
• Employing an atomically precise Au(111) single crystal for STM tip apex cleaning and preparation.

Main Results:

• The DSH successfully accommodates both a reference sample and an ancillary sample holder side-by-side.
• In situ tip apex re-preparation on the Au(111) reference sample was demonstrated.
• Atomic resolution imaging of 25 nm graphene nano-gears fabricated in a clean room was achieved.

Conclusions:

• The generalized DSH design enhances the capability of LT-UHV multi-probe STM systems.
• In situ tip preparation is crucial for reproducible atomic resolution imaging of sensitive samples.
• This approach facilitates the characterization of nanotechnology-fabricated devices within a UHV environment.