Patent classifications
G01R33/0325
MAGNETIC FIELD SENSOR USING ACOUSTICALLY DRIVEN FERROMAGNETIC RESONANCE
An acoustically driven ferromagnetic resonance (ADFMR) device includes a piezoelectric element, a pair of transducers arranged to activate the piezoelectric element to generate an acoustic wave, a magnetostrictive element arranged to receive the acoustic wave, and a readout circuit to detect one of either a change in the magnetostrictive element or a change in the acoustic wave.
MAGNETIC FIELD SENSOR USING ACOUSTICALLY DRIVEN FERROMAGNETIC RESONANCE
An acoustically driven ferromagnetic resonance (ADFMR) device has a piezoelectric element comprised of piezoelectric material, first and second electrodes arranged in a vertical stack with the piezoelectric element to activate the piezoelectric element to generate an acoustic wave, a radio frequency voltage source electrically connected to the first electrode, a magnet comprised of a magnetostrictive material in the vertical stack with the first and second electrodes and the piezoelectric element to receive the acoustic wave, wherein the acoustic wave resonates at a ferromagnetic resonance of the magnetostrictive material, and a readout circuit to detect a change in the acoustic wave by detecting one of an output voltage amplitude, a change in impedance or a reflection of the acoustic wave in the magnet to measure an unknown magnetic field in which the ADFMR device resides and as experienced at the magnetostrictive element.
Method for extracting a transverse magneto-optic effect signal
An apparatus to detect and measure a T-MOKE signal includes a first linear polarizer located on the optical path between a light source and a reflecting surface of a sample, a device to produce a magnetic field at the sample location, the device being configured to direct the magnetization perpendicularly to the optical plane of incidence and to reverse the direction of the magnetic field, a rotatable quarter-wave plate located after the reflecting surface on the optical path of the reflected light, a second linear polarizer that is rotatable and is located after the quarter-wave plate on the optical path of the reflected light, and a photo-detector located after the second linear polarizer on the optical path of the reflected light, the photo-detector being configured to measure the intensity of the light. A method for extracting a T-MOKE signal in an ellipsometric measurement procedure employs such an apparatus. The method includes a polarization detection scheme to ascertain that a T-MOKE signal (and not a noise signal) is indeed detected.
Apparatus, systems, and methods for measurement using magneto-optical Kerr effect
The magneto-optical Kerr effect (MOKE) is used to capture variations in magnetic permeability and magnetization to determine the presence of sensitization. MOKE-magnetometry-based systems and apparatus may be used to provide in-field magnetic measurements, and may be particularly useful in methods for assessing changes in composition, crystal structure, and grain size in magnetic materials.
MAGNETIC PROPERTY MEASURING SYSTEMS, METHODS FOR MEASURING MAGNETIC PROPERTIES, AND METHODS FOR MANUFACTURING MAGNETIC MEMORY DEVICES USING THE SAME
A magnetic property measuring system includes coil structures configured to apply a magnetic field to a sample, a light source configured to irradiate incident light to the sample, and a detector configured to detect polarization of light reflected from the sample. The magnetic field is perpendicular to a surface of the sample. Each coil structure includes a pole piece and a coil surrounding an outer circumferential surface of the pole piece. A wavelength of the incident light is equal to or less than about 580 nm.
Apparatus for testing sample properties in a magnetic field
A magnetic testing apparatus includes a magnet assembly with a sample path extending through the magnet assembly. The magnetic field produced by the magnet assembly defines a known, varying magnetic field profile along the sample path. A sample is moved along sample path such that the sample portion is subjected to a predetermined magnetic field ramp or magnetic field profile during a measurement period. A measurement arrangement is also provided to measure one or more properties of the sample during the measurement period, in order to test sample properties at a plurality of different magnetic fields. The apparatus may be particularly suited to magneto-optical measurements, including Magneto-Optical Kerr Effect measurements. The apparatus may be used for testing of hard disk platters.
Defect inspection device and defect inspection method
A defect inspection device configured to measure a surface shape of an inspection target using light applied to the inspection target via a spatial light phase modulator based on an interference state of reflected light from the inspection target obtained via the spatial light phase modulator, to measure magnetic field distribution of a surface of the inspection target magnetized by an excitation device for magnetizing the inspection target using light applied to the inspection target via the spatial light phase modulator based on an interference state of reflected light from the inspection target obtained via the spatial light phase modulator, and to separate data of a magnetic field specific portion which exists on the surface of the inspection target from magnetic field distribution data which is a measurement result of magnetic field distribution of the inspection target based on surface shape data which is a measurement result of the surface shape of the inspection target, to suppress deterioration of measurement accuracy of magnetic field distribution generated by the surface shape of the inspection target and to improve defect detection accuracy.
SEMICONDUCTOR MANUFACTURING DEVICE AND SEMICONDUCTOR MANUFACTURING METHOD
A semiconductor manufacturing device includes a detection unit that detects an extinction response of a perpendicular magnetic anisotropy PMA film in a sample from a polar Kerr effect signal, and a derivation unit that derives an anisotropic magnetic field (Hk) of the PMA film by extrapolating and fitting the detected extinction response, in magneto-optical Kerr effect measurement that uses a plurality of electromagnets that electrically apply magnetic fields to the sample on the stage by convert a perpendicular magnetic field that includes a vertical component normal to an upper surface of a stage, and a horizontal magnetic field parallel to the upper surface of the stage.
Inspection device and method for disposing magneto-optical crystal
An inspection device includes a light source, an MO crystal disposed to face a semiconductor device (D), an object lens configured to concentrate the light output from the light source onto the MO crystal, a holder configured to hold the MO crystal, a flexible member interposed between the MO crystal and the holder, and an object lens drive unit configured to cause the MO crystal to contact the semiconductor device (D) by causing the holder to be moved in the optical axis direction of the object lens, wherein, when the MO crystal contacts the semiconductor device (D), the flexible member is bent, so that an incident plane is inclined in a range in which an inclination angle of the incident plane of the light in the MO crystal with respect to a plane orthogonal to the optical axis is less than or equal to an aperture angle.
Heat-assisted rotating disk magnetometer for ultra-high anisotropy magnetic measurements
An apparatus comprises a spindle to rotate a magnetic recording medium and a magnetic field generator to expose a track of the medium to a DC magnetic field. The magnetic field generator is configured to saturate the track during an erase mode and reverse the DC magnetic field impinging the track during a writing mode. A laser arrangement heats the track during the erase mode and, during the writing mode, heats the track while the track is exposed to the reversed DC magnetic field so as to write a magnetic pattern thereon. A reader reads the magnetic pattern and generates a read signal. A processor is coupled to the reader and configured to determine an anisotropy parameter using the read signal. The apparatus can further comprise a Kerr sensor that generates a Kerr signal using the magnetic pattern.