A Magnetic Rotary Encoder for Patterned Media Lithography

2014 ◽  
Author(s):  
Shaomin Xiong ◽  
Yuan Wang ◽  
Xiang Zhang ◽  
David Bogy
Keyword(s):  
High Speed ◽  
New Technology ◽  
Hard Disk Drives ◽  
Magnetic Storage ◽  
Magnetic Islands ◽  
Bit Patterned Media ◽  
Patterned Media ◽  
Rotary Encoder ◽  
Digital Format ◽  
Field Programmable

Bit patterned media (BPM) is expected to enable the magnetic storage density in hard disk drives (HDDs) beyond 1 Tb/in2. BPM uses isolated magnetic islands to record the data information. However, the large volume fabrication of those patterned media disks at an affordable cost is a challenge for this new technology. A master template is the first step for patterned media fabrication. Using nano-imprint technology, the master template can be replicated to tens of thousands of pattern disks. A rotary electron beam lithography machine or plasmonic nanolithography machine is recommended to assist in the fabrication of the master template. In both systems, a high resolution encoder system for positioning in the rotary lithography machine is necessary. In this paper, a magnetic rotary encoder system is introduced. The encoder system can be operated at several thousand revolution per minute (RPM). The scale pitch is 90 nm which is one to two orders smaller than current optical encoders. The resolution is about 2.8 million counts per revolution (CPR). A flying magnetic head is used to retrieve the readback signal from the magnetic encoders. A field programmable gate array (FPGA) is implemented to finish the high speed signal processing and provide a digital format encoder signal to trigger the lithography machine at a rate of several Mega Hertz.

Repeatable Runout Following in Bit Patterned Media Recording

2014 ◽  
Author(s):  
Behrooz Shahsavari ◽  
Ehsan Keikha ◽  
Fu Zhang ◽  
Roberto Horowitz
Keyword(s):  
Controller Design ◽  
Hard Disk Drives ◽  
Lms Algorithm ◽  
Variable Step Size ◽  
Step Size ◽  
Bit Patterned Media ◽  
Patterned Media ◽  
Periodic Input ◽  
Feedforward Controller ◽  
Adaptive Feedforward

An adaptive feedforward controller design for tracking repeatable runout (RRO) in bit patterned media recording (BMPR) is proposed for single stage hard disk drives (HDD). The technique is based on a modified filtered-x least mean squares (MFX-LMS) algorithm with deterministic periodic input, and a novel variable step size that boosts both the convergence rate and the steady state error. Comprehensive simulations are provided to show the effectiveness of the proposed method.

scholarly journals Modulation Code for Reducing Intertrack Interference on Staggered Bit-Patterned Media Recording

2020 ◽  
Vol 10 (15) ◽  
pp. 5295 ◽  
Author(s):  
Seongkwon Jeong ◽  
Jaejin Lee
Keyword(s):  
Storage System ◽  
Areal Density ◽  
Magnetic Storage ◽  
Two Dimensional ◽  
Bit Patterned Media ◽  
Patterned Media ◽  
Cross Track ◽  
Modulation Code ◽  
Intertrack Interference

A bit-patterned media recording (BPMR) system is a type of ultrahigh-capacity magnetic storage system that can extend to an areal density of 1 terabit per square inch or higher. However, because the space between islands in the down- and cross-track directions is reduced to extend the areal density, the effect of two-dimensional interference is increased. However, using a staggered array, which is one of the possible island distributions for BPMR, helps to decrease intertrack interference. A 7/10 modulation code for a staggered BPMR is proposed to avoid the effect of two-dimensional interference and provide distance among nonidentical codewords for improving the correcting capability.

Microfabrication research at the National Submicron Facility

1983 ◽  
Vol 41 ◽  
pp. 86-89
Author(s):  
E.D. Wolf
Keyword(s):  
Integrated Circuits ◽  
Particle Physics ◽  
High Speed ◽  
New Technology ◽  
High Energy ◽  
High Energy Particle ◽  
New Science ◽  
Wide Range ◽  
Intermediate Domain ◽  
Circuit Function

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.

Accelerating laser processes with a smart two-dimensional polygon mirror scanner for ultra-fast beam deflection

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Florian Roessler ◽  
André Streek
Keyword(s):  
Energy Distribution ◽  
Real Time ◽  
Laser Processing ◽  
High Speed ◽  
Beam Deflection ◽  
Two Dimensional ◽  
Heat Accumulation ◽  
Field Programmable ◽  
Drill Holes ◽  
Average Laser

Abstract In laser processing, the possible throughput is directly scaling with the available average laser power. To avoid unwanted thermal damage due to high pulse energy or heat accumulation during MHz-repetition rates, energy distribution over the workpiece is required. Polygon mirror scanners enable high deflection speeds and thus, a proper energy distribution within a short processing time. The requirements of laser micro processing with up to 10 kW average laser powers and high scan speeds up to 1000 m/s result in a 30 mm aperture two-dimensional polygon mirror scanner with a patented low-distortion mirror configuration. In combination with a field programmable gate array-based real-time logic, position-true high-accuracy laser switching is enabled for 2D, 2.5D, or 3D laser processing capable to drill holes in multi-pass ablation or engraving. A special developed real-time shifter module within the high-speed logic allows, in combination with external axis, the material processing on the fly and hence, processing of workpieces much larger than the scan field.

Based on FPGA Intelligent Physiological Parameters Acquisition

2013 ◽  
Vol 344 ◽  
pp. 107-110
Author(s):  
Shun Ren Hu ◽  
Ya Chen Gan ◽  
Ming Bao ◽  
Jing Wei Wang
Keyword(s):  
High Speed ◽  
Low Cost ◽  
Physiological Parameters ◽  
Sensor Data ◽  
Low Power Consumption ◽  
Physiological Signal ◽  
Pulse Sensor ◽  
Monitoring Applications ◽  
Field Programmable ◽  
Design Ideas

For the physiological signal monitoring applications, as a micro-controller based on field programmable gate array (FPGA) physiological parameters intelligent acquisition system is given, which has the advantages of low cost, high speed, low power consumption. FPGA is responsible for the completion of pulse sensor, the temperature sensor, acceleration sensor data acquisition and serial output and so on. Focuses on the design ideas and architecture of the various subsystems of the whole system, gives the internal FPGA circuit diagram of the entire system. The whole system is easy to implement and has a very good promotional value.

Resistless Patterning of Magnetic Storage Media Using Ion Projection Structuring

2001 ◽  
Vol 705 ◽  
Author(s):  
A. Dietzel ◽  
R. Berger ◽  
H. Grimm ◽  
C. Schug ◽  
W. H. Bruenger ◽  
...  
Keyword(s):  
Process Development ◽  
Ion Beam ◽  
Silicon On Insulator ◽  
Magnetic Storage ◽  
Magnetic Islands ◽  
Superlattice Structure ◽  
Head Positioning ◽  
Out Of Plane ◽  
Set Up ◽  
The Impact

AbstractCo/Pt thin film multilayers with strong perpendicular anisotropy and out-of-plane coercivities of 5-11 kOe were magnetically altered in areas of local ion beam interaction. The ion irradiations were performed by ion projection through silicon stencil masks fabricated by silicon on insulator (SOI) membrane technology. The ion projector at the Fraunhofer Institute for Silicon Technology (ISiT) was operated at 73 keV ion energy and with a 8.7- fold demagnification. After exposure to 3 × 1014Ar+/ cm2 magnetic islands smaller than 100 nm in diameter were resolved in the Co/Pt multilayersby means of magnetic force microscopy. The impact of different ion species (He+, Ar+ and Xe+) and ion energies (10 – 200 keV) on the multilayer structure was evaluated using Monte Carlo simulations. The ballistic interface intermixing was used to predict magnetic coercivity changes for various irradiation conditions. The simulations revealed that with 73 keV Ar+ and Xe+ ions the irradiation dose could be reduced by a factor of 100 and 400 respectively in comparison to 73 keV He+which was verified in the experiments. X-ray reflectivity measurements confirmed that the Co/Pt superlattice structure is slightly weakened during the irradiation and that the surface smoothness of the media is preserved. Using the Ion Projection Process Development Tool (PDT) at IMS-Vienna concentric data tracks including head positioning servo informations were patterned onto a 1” IBM microdrive™ glass disk which was coated with Co/Pt multilayers. In a single exposure step several tracks within an exposure field of 17 mm in diameter were structured by 2 × 1015He+/ cm2 at 45 keV using a 4- fold demagnification set-up.

Determination of Bit Patterned Media Noise Based on Island Perimeter Fluctuations

2012 ◽  
Vol 48 (11) ◽  
pp. 4574-4577 ◽  
Author(s):  
Laurens Alink ◽  
J. P. J. Groenland ◽  
Jeroen de Vries ◽  
Leon Abelmann
Keyword(s):  
Bit Patterned Media ◽  
Patterned Media ◽  
Media Noise
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