Rapid and localized ion-beam etching of surfaces using initial notches

Area of Science:

• Materials Science
• Surface Engineering
• Microscopy Sample Preparation

Background:

• Glancing-angle broad ion beam erosion is a standard technique for transmission electron microscopy (TEM) sample preparation.
• Current methods suffer from low erosion rates and lack of site specificity, limiting workflow efficiency.
• Focused ion beam methods are effective but expensive and complex.

Purpose of the Study:

• To develop a novel, rapid, and site-specific surface erosion method for TEM sample preparation.
• To overcome the limitations of traditional broad ion beam erosion techniques.
• To demonstrate the feasibility of the new method by preparing an electron-transparent lamella.

Main Methods:

• Combining ultrashort-pulsed laser machining with broad ion beam etching.
• Creating precisely located notches (iNotches™) on (100)-Si substrates using a laser.
• Utilizing preferential erosion at glancing angles behind laser-induced notches.
• Characterizing surface topography and comparing with 2D deterministic model simulations.

Main Results:

• Laser-induced notches created localized changes in surface inclination.
• Preferential erosion behind notches resulted in a terrace structure with a defined height jump.
• The method demonstrated rapid and localized surface erosion.
• An electron-transparent lamella was successfully prepared as proof of concept.

Conclusions:

• The combined laser-machining and ion beam etching method significantly enhances erosion rates and site specificity.
• The iNotches™ workflow offers a cost-effective and efficient alternative for TEM sample preparation.
• This technique has the potential to improve existing sample preparation workflows.