Searcharxiv⌕ Search

arXiv · cond-mat/0512283

Focused-ion-beam milling based nanostencil mask fabrication for spin transfer torque studies

Abstract

Focused-ion-beam milling is used to fabricate nanostencil masks suitable for the fabrication of magnetic nanostructures relevant for spin transfer torque studies. Nanostencil masks are used to define the device dimensions prior to the growth of the thin film stack. They consist of a wet etch resistant top layer and an insulator on top of a pre-patterned bottom electrode. The insulator supports a hard mask and gives rise to an undercut by its selective etching. The approach is demonstrated by fabricating current perpendicular to the plane Co/Cu/Co nanopillar junctions, which exhibit current-induced magnetization dynamics.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

B. Oezyilmaz, G. Richter, N. Muesgens, M. Fraune, M. Hawraneck, B. Beschoten, G. Guentherodt, M. Bueckins, J. Mayer. 2005-12-13. Focused-ion-beam milling based nanostencil mask fabrication for spin transfer torque studies. https://doi.org/10.1063/1.2711785

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Modification of Damon-Eshbach magnetostatic mode spectra in ferromagnet/paramagnet bilayer

Using the magnetostatic approximation, we calculate the spectra of bulk and surface spin waves in an in-plane magnetized ferromagnet/paramagnet bilayer. Due to the dipolar coupling between the layers, the paramagnet becomes polarized, which in turn modifies the spectrum of the Damon-Eshbach magnetostatic modes. We assume that the paramagnet is characterized by a magnetic susceptibility, $χ\propto 1/(T-T_C)$, which reaches large values when the system temperature $T$ is close to the Curie temperature $T_C$. We find the conditions under which surface spin waves become unidirectional, i.e., capable of carrying energy in only one direction, and determine the magnitude of their frequency nonreciprocity. We demonstrate the possibility of switching the unidirectional wave regime on and off by varying the external magnetic field or temperature, making the ferromagnet/paramagnet system an attractive platform for tunable magnonic logic devices.

cond-mat.mes-hall↗

Sub-kelvin cryogenic wafer probing verified by on-wafer primary Coulomb blockade thermometry

Scalable cryogenic wafer level testing is emerging as an essential tool for the development of quantum devices and cryogenic microelectronics, but the main motivation, the actual operational on-wafer temperature, remains largely unverified. In this work, utilizing a cryogenic wafer prober (CWP) enables wafer-scale electrical testing of Coulomb blockade thermometers (CBTs), while the CBTs simultaneously provide an independent static and dynamic assessment of the prober's thermal performance through primary and in situ calibrated secondary electron thermometry, realizing a reciprocal characterization approach. Using recently introduced scalable normal metal TiW-based CBTs, which require no superconductivity suppressing magnetic fields, we have measured on-wafer electron temperatures of 630-660 mK across a full 150 mm wafer, representing, to our knowledge, record-low electron temperatures measured in a CWP. These exceed the nominal 600 mK chuck setpoint by approximately 40 mK on average, demonstrating the necessity of direct on-wafer thermometry. Self-calibrated secondary CBT thermometry resolves the thermal transients caused by chuck movement and reveals a thermal settling time within 5 minutes after probe touch down. This reciprocal wafer-scale approach simultaneously evaluates the device under test and the thermal performance of the measurement environment, providing a practical methodology for scalable sub-kelvin characterization of quantum devices and cryogenic microelectronics.

cond-mat.mes-hall↗

Anisotropic wavevector-dependent damping of thickness-quantized magnons

Magnon damping is a key factor governing spin-wave transport and nonlinear dynamics of multimode magnon systems. However, many descriptions rely on the assumption of an effective mode-independent parameter, which can mask wavelength-dependent relaxation processes that depend on propagation geometry and mode profile. Here, we employ high-resolution parametric-instability spectroscopy to probe thickness-quantized spin waves with wavelengths down to about a hundred nanometers in micrometer-thick yttrium iron garnet films. The instability threshold exhibits a regular sawtooth dependence on the magnetic field, arising from switching between discrete thickness modes. Comparison with dipole--exchange theory reveals anisotropic wavevector-dependent damping that increases with mode number and depends differently on the in-plane and out-of-plane wavevector components.

cond-mat.mes-hall↗