Fabrication and use of a nanoscale Hall probe for measurements of the magnetic field induced by MFM tips

Abstract

Extraordinary Hall effect probes with 160 nm × 160 nm working area were fabricated using photo- and electron-beam lithographic procedures with the aim of direct measurements of MFM cantilever tip magnetic properties. The magnetic field sensitivity of the probes was 35 Ω T(-1). Magnetic induction of the MFM cantilever tips coated by Co and SmCo films was measured with the probes. It was shown that the resolution of the probes was of the order of 10 nm.

Hall effect sensors on the basis of carbon material

“…Aluminum film was deposited by electron-beam deposition. Laser ablation was used [3] for Fe deposition and Ni was deposited by the self ion assisted deposition technique [26]. The substrate with catalyst bilayer was annealed in air for two minutes at 800°C in order to form catalyst nanoparticles.…”

“…Such sensors with an active area of micron and submicron sizes are fabricated from various metals (Au, Al) [1], alloys (NiFe) [2], (FePt) [3], semimetals (Bi) [1,4], semiconductors (InSb) [5,6], (InAs) [8], on the basis of two-dimensional electron gas (2DEG) [1,[8][9][10] and graphene [11][12][13]. A specific ferromagnetic effect, known as extraordinary or anomalous Hall effect, is observed in FePt films [14].…”

“…S ordinarily drops as the sensor active area decreases [9,12]. In recent years Hall sensors have been actively developed for scanning probe microscopy operating at room temperature [4,8] and for calibration of magnetic cantilevers in magnetic force microscopy [3,11]. A sensor of minimal size 50 Â 50 nm 2 with the magnetic field sensitivity 40 Ω/ T was fabricated from Bi [4] and a sensor of maximum S¼ 1250 Ω/T with active area size of 1 Â 1 mm 2 was fabricated from graphene grown on SiC [11].…”

“…The films were grown at a temperature of 890°(1, 6), 912°(2, 7), 925°(3,8), 938°(4,9), 950°C (5, 10).…”

Three-axis Hall transducer based on semiconductor microtubes

“…However, the near-surface depletion of GaAs will hardly permit a reduction of the thickness of GaAs-based conducting films below ≈30 nm with preservation of reasonable carrier concentration and mobility values. In this connection, promising objects for scaling shell-based devices into the nano-scale region involve: (i) shells based on narrow-gap semiconductors [16], (ii) hybrid shells in which semiconductor layers can be used as shape-defining layers, and the active conducting layer can be a metal layer (for instance, a 2-nm thick FePt layer, in which an anomalous Hall effect was observed [17]), and (iii) graphene-based shells [18].…”