Abstract: In one embodiment, a first storage storing writing data, a second storage storing correction data for correcting an error in a writing position due to factors including bending of the substrate, a cell data allocator virtually dividing a writing region of the substrate into blocks, and allocating a cell to the blocks in consideration of the correction data, a plurality of bitmap data generators virtually dividing the blocks into meshes, calculating an irradiation amount per mesh region, and generating bitmap data which assigns the irradiation amount to each mesh region, and a shot data generator generating shot data that defines an irradiation time for each beam. The cell data allocator virtually divides the writing region by division lines in a direction different from a writing forward direction to generate a plurality of division regions. The plurality of bitmap data generators generate pieces of bitmap data of the different division regions.

Abstract: In one embodiment, a first storage storing writing data, a second storage storing correction data for correcting an error in a writing position due to factors including bending of the substrate, a cell data allocator virtually dividing a writing region of the substrate into blocks, and allocating a cell to the blocks in consideration of the correction data, a plurality of bitmap data generators virtually dividing the blocks into meshes, calculating an irradiation amount per mesh region, and generating bitmap data which assigns the irradiation amount to each mesh region, and a shot data generator generating shot data that defines an irradiation time for each beam. The cell data allocator virtually divides the writing region by division lines in a direction different from a writing forward direction to generate a plurality of division regions. The plurality of bitmap data generators generate pieces of bitmap data of the different division regions.

Abstract: According to one embodiment, a magnetic disk device includes a disk including a tracks including a servo region, a light irradiator configured to irradiate the disk with light and heat the disk with the light, a head including a write head configured to write data in a range irradiated and heated with the light, and a read head configured to read data from the tracks, a controller configured to write first data to be used for offset detection in a first region of the tracks, read the first data from the first region with reference to servo data in the servo region, detect an offset of the read head based on an amplitude of a first signal of the first data, and control a position of the read head based on the offset.

Abstract: According to one embodiment, a magnetic disk device includes a disk including a tracks including a servo region, a light irradiator configured to irradiate the disk with light and heat the disk with the light, a head including a write head configured to write data in a range irradiated and heated with the light, and a read head configured to read data from the tracks, a controller configured to write first data to be used for offset detection in a first region of the tracks, read the first data from the first region with reference to servo data in the servo region, detect an offset of the read head based on an amplitude of a first signal of the first data, and control a position of the read head based on the offset.

Abstract: According to one embodiment, a magnetic recording medium used in a heat assisted magnetic recording system includes a magnetic recording layer and a metal particle layer in which metal particles are arranged in a dispersed manner on a substrate. In the metal particle layer, percentage content of the metal particles in a second region positioned at an outer periphery side of a first region is higher than that of the first region in a surface direction of the substrate.

Abstract: According to one embodiment, a magnetic recording medium includes a magnetic recording layer formed on a substrate and including magnetic grains and a grain boundary formed between the magnetic grains, the grain boundary includes a first grain boundary having a first thermal conductivity, and a second grain boundary formed on the first grain boundary and having a second thermal conductivity different from the first thermal conductivity, and at least one of the first and second grain boundaries suppresses thermal conduction.

Abstract: A storage apparatus includes a magnetic storage medium which is formed with a data portion based on isolated magnetic dots and a servo pattern portion, a drive mechanism which drives the storage medium, a head actuator which includes a head for reading and writing data from and to the storage medium, and a permanent magnet which is disposed at a position that is opposable to a whole radial region of the servo pattern portion, during a rotation of the storage medium.

Abstract: A magnetic recording medium includes a plurality of recording tracks formed of a magnetic material and a non-magnetic area arranged between the recording tracks to separate each recording track. The non-magnetic area is formed of a non-magnetic material, which can accumulate and retain electric charges. The electric charges accumulated in the non-magnetic area represent servo information.

Abstract: A storage apparatus includes a magnetic storage medium which is formed with a data portion based on isolated magnetic dots and a servo pattern portion, a drive mechanism which drives the storage medium, a head actuator which includes a head for reading and writing data from and to the storage medium, and a permanent magnet which is disposed at a position that is opposable to a whole radial region of the servo pattern portion, during a rotation of the storage medium.

Abstract: A write-head positioning method includes steps of positioning a write head on a first track of a storage medium on the basis of a servo signal and writing a signal on the first track, positioning the write head on second and third tracks located adjacent to opposite sides of the first track on the basis of servo signals and writing signals on the second track and the third track, positioning the read head at positions on the first track that are set at a predetermined interval in a track-width direction, and reading a signal from the first track at each position thereof, determining a signal profile that indicates a fluctuation of output values of the signals read at the respective positions on the first track, and detecting a peak position indicating a maximum output value in the determined signal profile.

Abstract: A write-head positioning method includes steps of positioning a write head on a first track of a storage medium on the basis of a servo signal and writing a signal on the first track, positioning the write head on second and third tracks located adjacent to opposite sides of the first track on the basis of servo signals and writing signals on the second track and the third track, positioning the read head at positions on the first track that are set at a predetermined interval in a track-width direction, and reading a signal from the first track at each position thereof, determining a signal profile that indicates a fluctuation of output values of the signals read at the respective positions on the first track, and detecting a peak position indicating a maximum output value in the determined signal profile.

Abstract: The difference is detected between the outputs from first and second heads in a recording medium drive. The first head is positioned relative to the boundary between a first recording track and a separation track isolating the first recording track and a second recording track from each other. The second head is positioned relative to the boundary between the separation track and the second recording track. A position information specifying the positions of the first and second heads are generated based on the difference. The first and second heads follow the different boundaries, so that the outputs of the first and second heads reliably vary. The difference between the outputs thus reliably changes. An accurate position information can be generated based on the difference. The position information may be utilized in tracking servo control, for example. This enables establishment of the tracking servo control with a higher accuracy.

Abstract: As the surface of a main pole facing a magnetic disk, one with a rectangle-shaped part whose width in a radius direction consecutively changes in a direction orthogonal to the radius direction of the magnetic disk is adopted. The rectangle-shaped part has two sides facing each other in the orthogonal direction. Two angles formed by one of the two sides and two sides touching the side are different. One of the two angles is in the neighborhood of 90 degrees including 90 degrees. Adopting such a shape, a magnetic head capable of suppressing side write can be more easily fabricated.

Abstract: The difference is detected between the outputs from first and second heads in a recording medium drive. The first head is positioned relative to the boundary between a first recording track and a separation track isolating the first recording track and a second recording track from each other. The second head is positioned relative to the boundary between the separation track and the second recording track. A position information specifying the positions of the first and second heads are generated based on the difference. The first and second heads follow the different boundaries, so that the outputs of the first and second heads reliably vary. The difference between the outputs thus reliably changes. An accurate position information can be generated based on the difference. The position information may be utilized in tracking servo control, for example. This enables establishment of the tracking servo control with a higher accuracy.

Abstract: An electron beam tester scans a sample with an electron beam to provide a secondary electron image, matches wiring patterns of the secondary electron image with wiring patterns prepared from CAD data, measures voltages of the wiring patterns, and corrects deformation of the secondary electron image. The electron beam tester comprises a pattern matching unit, a wiring pattern tester, a secondary electron image corrector, a wiring pattern inspection unit, and a pattern matching processor. The pattern matching unit simply and quickly matches the wiring patterns of the secondary electron image with the wiring patterns prepared from the CAD data. The wiring pattern tester detects slippage between layers of a multilayered semiconductor chip and correctly positions the electron beam on the chip during a pattern matching operation. The secondary electron image corrector accurately and automatically corrects deformation of the secondary electron image.

Abstract: An Electron Beam Tester which corrects deformation of a secondary electron image produced from scanning a sample with an electron beam. The secondary electron image is stored in a storage unit. Luminance data of the stored image is accumulated to obtain a projected luminance distribution. The projected luminance distribution data is then analyzed by a parallelism evaluation unit to obtain a rotation angle. Then the rotation angle is used to determine maximum parallelism and correct deformation of the secondary electron image by providing deflection control which transforms the deflectors .

Abstract: An electron beam tester scans a sample with an electron beam to provide a secondary electron image, matches wiring patterns of the secondary electron image with wiring patterns prepared from CAD data, measures voltages of the wiring patterns, and corrects deformation of the secondary electron image. The electron beam tester comprises a pattern matching unit, a wiring pattern tester, a secondary electron image corrector, a wiring pattern inspection unit, and a pattern matching processor. The pattern matching unit simply and quickly matches the wiring patterns of the secondary electron image with the wiring patterns prepared from the CAD data. The wiring pattern tester detects slippage between layers of a multilayered semiconductor chip and correctly positions the electron beam on the chip during a pattern matching operation. The secondary electron image corrector accurately and automatically corrects deformation of the secondary electron image.

Abstract: A method of measuring a voltage with an electron beam apparatus considers a change in a convergence factor due to a change in an S curve, as well as an error in a secondary electron signal level with a phase of measurement being scanned at random, to accurately measure the voltage. The method measures the voltage of a voltage measuring spot on a sample, prepares an analytic voltage by superimposing a probe voltage having an average of 0 V and no correlation with the measured voltage on the measured voltage, measures a secondary electron signal level with the analytic voltage, computes a convergence factor around a slice level set on the S curve according to a correlation between the secondary electron signal level and the probe voltage and according to an autocorrelation of the probe voltage, and updates the analytic voltage according to the convergence factor, thereby updating the measured voltage.

Abstract: A method of measuring a voltage with an electron beam apparatus considers a change in a convergence factor due to a change in an S curve, as well as an error in a secondary electron signal level with a phase of measurement being scanned at random, to accurately measure the voltage. The method measures the voltage of a voltage measuring spot on a sample, prepares an analytic voltage by superimposing a probe voltage having an average of 0 V and no correlation with the measured voltage on the measured voltage, measures a secondary electron signal level with the analytic voltage, computes a convergence factor around a slice level set on the S curve according to a correlation between the secondary electron signal level and the probe voltage and according to an autocorrelation of the probe voltage, and updates the analytic voltage according to the convergence factor, thereby updating the measured voltage.