Optical Nanoscopy of High-Tc Cuprate Nano-Constriction Devices Patterned by Helium Ion Beams

Abstract

Helium-ion beams (HIB) focused to sub-nanometer scales have emerged as powerful tools for high-resolution imaging as well as nano-scale lithography, ion milling or deposition. Quantifying irradiation effects is essential for reliable device fabrication but most of the depth profiling information is provided by computer simulations rather than experiment. Here, we use atomic force microscopy (AFM) combined with scanning near-field optical microscopy (SNOM) to provide three-dimensional (3D) dielectric characterization of high-temperature superconductor devices fabricated by HIB. By imaging the infrared dielectric response we find that amorphization caused by the nominally 0.5 nm HIB extends throughout the entire 26.5 nm thickness of the cuprate film and by about 500 nm laterally. This unexpectedly widespread structural and electronic damage can be attributed to a Helium depth distribution substantially modified by internal device interfaces. Our study introduces AFM-SNOM as a quantitative nano-scale tomographic technique for non-invasive 3D characterization of irradiation damage in a wide variety of devices.

arXiv comment9 pages, 5 figures

References in corpus (5)

• High-temperature interface superconductivity between metallic and insulating cuprates
• Interplay of electron-lattice interactions and superconductivity in Bi2Sr2CaCu2O8+d
• Precision Cutting and Patterning of Graphene with Helium Ions
• Helium Ion Microscopy
• Model for quantitative tip-enhanced spectroscopy and the extraction of nanoscale-resolved optical constants

Cited by in corpus (6)

• Single-photon detection using high-temperature superconductors
• Josephson junctions and SQUIDs created by focused helium ion beam irradiation of YBa${}_2$Cu${}_3$O${}_7$
• Dynamic properties of high-Tc superconducting nano-junctions made with a focused helium ion beam
• Surface Josephson plasma waves in a high-temperature superconductor
• Angle-dependent Magnetoresistance of an Ordered Bose Glass of Vortices in YBa${}_2$Cu${}_3$O${}_{7-\delta }$ Thin Films with a Periodic Pinning~Lattice
• Nanostructured Superconductors