Electronic Transport in Helium Beam Modified Graphene and Ballistic Josephson Junctions

This thesis describes the capabilities of the helium ion microscope (HIM) and that of graphene to explore fundamental physics and novel applications. While graphene offers superior electronic properties, the helium ion microscope allows us to combine imaging and modification of materials at the nanoscale. We used the capabilities of HIM to grow...

Current-Phase Relation of Ballistic Graphene Josephson Junctions

The current-phase relation (CPR) of a Josephson junction (JJ) determines how the supercurrent evolves with the superconducting phase difference across the junction. Knowledge of the CPR is essential in order to understand the response of a JJ to various external parameters. Despite the rising interest in ultraclean encapsulated graphene JJs,...

Electronic transport in helium-ion-beam etched encapsulated graphene nanoribbons

We report the etching of and electronic transport in nanoribbons of graphene sandwiched between atomically flat hexagonal boron nitride (h-BN). The etching of ribbons of varying width was achieved with a focused beam of 30 keV He⁺ ions. Using in-situ electrical measurements, we established a critical dose of 7000 ions nm<sup>−2<...

Deep sub-wavelength metrology for advanced defect classification

Particle defects are important contributors to yield loss in semi-conductor manufacturing. Particles need to be detected and characterized in order to determine and eliminate their root cause. We have conceived a process flow for advanced defect classification (ADC) that distinguishes three consecutive steps; detection, review and...

Helium-ion-beam-induced growth of 3-dimensional AFM probes

Helium ion beam induced growth of hammerhead AFM probes

The authors report the direct-write growth of hammerhead atomic force microscope(AFM) probes by He+beam induced deposition of platinum-carbon. In order to grow a thin nanoneedle on top of a conventional AFM probe, the authors move a focused He+beam during exposure to a PtC precursor gas. In the final growth stage, a perpendicular movement of the...