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Title: Self-sensing cantilevers with integrated conductive coaxial tips for high-resolution electrical scanning probe metrology

The lateral resolution of many electrical scanning probe techniques is limited by the spatial extent of the electrostatic potential profiles produced by their probes. Conventional unshielded conductive atomic force microscopy probes produce broad potential profiles. Shielded probes could offer higher resolution and easier data interpretation in the study of nanostructures. Electrical scanning probe techniques require a method of locating structures of interest, often by mapping surface topography. As the samples studied with these techniques are often photosensitive, the typical laser measurement of cantilever deflection can excite the sample, causing undesirable changes electrical properties. In this work, we present the design, fabrication, and characterization of probes that integrate coaxial tips for spatially sharp potential profiles with piezoresistors for self-contained, electrical displacement sensing. With the apex 100 nm above the sample surface, the electrostatic potential profile produced by our coaxial tips is more than 2 times narrower than that of unshielded tips with no long tails. In a scan bandwidth of 1 Hz–10 kHz, our probes have a displacement resolution of 2.9 Å at 293 K and 79 Å at 2 K, where the low-temperature performance is limited by amplifier noise. We show scanning gate microscopy images of a quantum point contact obtained with our probes, highlighting the improvementmore » to lateral resolution resulting from the coaxial tip.« less
Authors:
;  [1] ;  [2] ; ; ;  [3]
  1. Department of Mechanical Engineering, Stanford University, 440 Escondido Mall, Stanford, North Carolina 94305 (United States)
  2. Department of Electrical Engineering, Stanford University, 350 Serra Mall, Stanford, North Carolina 94305 (United States)
  3. Department of Physics, Stanford University, 382 Via Pueblo Mall, Stanford, North Carolina 94305 (United States)
Publication Date:
OSTI Identifier:
22489527
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 118; Journal Issue: 3; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AMPLIFIERS; ATOMIC FORCE MICROSCOPY; DESIGN; ELECTRIC CONTACTS; ELECTRICAL PROPERTIES; FABRICATION; IMAGES; KHZ RANGE; LASERS; MAPPING; NANOSTRUCTURES; NOISE; PERFORMANCE; POTENTIALS; PROBES; SPATIAL RESOLUTION; SURFACES