Nanoscale patterning at the Si/SiO₂/graphene interface by focused He⁺ beam

Area of Science:

• Materials Science
• Nanotechnology
• Surface Science

Background:

• Graphene and Si/SiO2 interfaces are crucial for advanced electronics and catalysis.
• Focused ion beam (FIB) techniques offer precise material modification.
• Understanding ion-matter interactions is key to controlling nanoscale properties.

Purpose of the Study:

• To investigate the capability of Helium ion beam (He+-FIB) patterning for creating defect arrays on Si/SiO2/Graphene interfaces.
• To analyze the impact of ion dose and spot spacing on surface morphology and material modification.
• To explore the potential of these defect arrays for applications like heterogeneous catalysis.

Main Methods:

• Utilized He+-FIB patterning to create defect arrays.
• Employed atomic force microscopy (AFM) for topographical analysis.
• Applied Raman imaging and X-ray photoionization spectroscopy (XPS) to characterize material and chemical modifications.

Main Results:

• He+-FIB creates amorphized regions with topography dependent on ion dose and spot spacing.
• Increased ion dose leads to subsurface amorphization and height increase.
• Graphene defects, oxidation, and Si/SiO2/C bond rearrangement (forming SiC, SiOC) were observed with varying ion doses and spacing.

Conclusions:

• He+-FIB is effective for fabricating defect arrays on Si/SiO2/Graphene.
• The study provides parameter ranges for defect array generation.
• These patterned interfaces show potential for pinning nanoparticles in heterogeneous catalysis research.