Rany Elsayed - Academia.edu (original) (raw)
Papers by Rany Elsayed
This paper presents a design example that illustrates the potential of microelectromechanical sys... more This paper presents a design example that illustrates the potential of microelectromechanical systems (MEMS) to perform the mechanical positioning required for addressing stored data and to enable an entirely new mechanism for reading and writing magnetic data. Specifically, MEMS sensors and actuators can be used to achieve active servo control of the separation between magnetic probe tips and a media surface with sub-nanometer accuracy.
In this research we have extensively analyzed and optimized the performance of MEMS-positioned, n... more In this research we have extensively analyzed and optimized the performance of MEMS-positioned, nonvolatile, re-writable, mass storage devices with MFM-based single-pole read/write magnetic tips currently under development at Carnegie Mellon University. This has been achieved through general design consideration investigation, analytical modeling, and through in-depth micromagnetic modeling and simulations. For micromagnetic modeling, two simulators were especially designed and built by the author to study and analyze the performance of the MFM-based MEMS-actuated mass storage device. The simulators have been tested and verified using the standard problem #1 proposed by the Micromagnetic Modeling Activity Group (muMAG) in the NIST Center for Theoretical and Computational Materials Science (CTCMS). In general design consideration investigation, many important concepts and observations have been developed. First, the tip field amplitude and gradient dependence on tip size has been stu...
2000 IEEE International Symposium on Circuits and Systems. Emerging Technologies for the 21st Century. Proceedings (IEEE Cat No.00CH36353), 2000
This paper addresses the design of an analog very large-scale integration (VLSI) high accuracy ne... more This paper addresses the design of an analog very large-scale integration (VLSI) high accuracy neural cell with supervised learning ability using standard 2-µm CMOS technology. A novel architecture is presented such that all cells, input, output, or hidden, have the same architecture which ensures a high degree of flexibility in terms of topology programming. Moreover, in designing the cell architecture, a new design technique based on hardware functionality multiplexing is employed. This technique resulted in a considerable compact cell. On the circuit level, the cell design is based mainly on a novel very high accuracy switched-current (SI) memory cell. With minor modifications, the SI memory cell is used in building all of the switched-current-based modules in the cell, which resulted in a high accuracy neural cell. The performance and timing for the separate modules and the whole cell are extensively studied. The cell is tested through a Multi-Layer Perceptron Network (MLP) using SPICE to solve the digit recognition problem.
IEEE Transactions on Semiconductor Manufacturing, 2000
In this paper, we present a novel methodology for fully characterizing back-end interconnect line... more In this paper, we present a novel methodology for fully characterizing back-end interconnect lines. The use of the proposed new hybrid resistive e-test and SEM imaging algorithm addresses several practical issues. First it overcomes the inaccuracy of back-end estimation based on full capacitive measurement due to neglecting sidewall slope. Depending on the sidewall slope, a significant error in the estimation of line width, line thickness, side line space, and ILD thickness can result. This impact is shown to increase as interconnect geometry scales down. Secondly, it accommodates the limited silicon area in test chips. Finally, in addition to systematic behavior, the methodology accurately estimates and re-produces random component to fully re-construct the behavior of the interconnects on actual Si.
IEEE Transactions on Magnetics, 2002
IEEE Transactions on Magnetics, 2004
In this work, we present three magnetic force microscopy (MFM)-compatible pulse-width-modulation ... more In this work, we present three magnetic force microscopy (MFM)-compatible pulse-width-modulation (PWM) coding scheme to be employed in scanning-probe storage devices. For each code, analytical models describing the code length utilization [CLU, i.e., non-return-to-zero (NRZ) code length to PWM code length ratio] and the signal-to-quantization noise ratio (SQNR) resulting from the granularity of the media are derived. To verify the models, a micromagnetic model was constructed. Using a proposed variable-length PWM coding scheme with 3 bits/symbol, 30-nm tip diameter, and a fractional step of 20% of the initial mark, a 82% increase in areal density over optimized regular NRZ single-bit coding is shown to be achievable (i.e., 1.26 Tb/in 2 ) with an SQNR of 17.2 dB and an overall SNR of 13.1 dB.
IEEE Transactions on Magnetics, 2003
In this paper, we present an analysis of the performance of a 0.3-Tb/in 2 ultralow-power magnetic... more In this paper, we present an analysis of the performance of a 0.3-Tb/in 2 ultralow-power magnetic-forcemicroscopy-based scanning-probe storage device actuated by microelectromechanical systems technology. The device is currently under development at Carnegie Mellon University, Pittsburgh, PA. The analysis shows that, with an optimized commercial single-layered Co-based perpendicular medium with an optimized tip trajectory, a signal-to-noise ratio of 20-25 dB is achievable. The analysis includes general design considerations as well as various aspects of performance such as recording dynamics, 50 , intersymbol-interference limit, detection sensitivity, thermal degradation, intertrack interference, off-track errors, process variations, and surface fluctuation effect. Design/performance standards for the new device are suggested.
IEEE Transactions on Magnetics, 2000
In this paper, we investigate the feasibility of using a magnetic force microscopy scheme for rec... more In this paper, we investigate the feasibility of using a magnetic force microscopy scheme for recording and retrieving magnetic marks for ultrahigh-density, ultralow power applications. We will address the main design considerations while designing such a system. Then, using the impulse-response and inverse-convolution technique, we deduce a novel tip trajectory for the optimum recording process. We will also apply extensive optimization for a Co x Cr y Pt 1 x y perpendicular media structure to maximize the signal-to-noise ratio (SNR). An areal density of up to 0.3 Tb in 2 is shown to be achievable with thermally stable magnetic marks and a SNR of 20-25 dB in the existence of additional electronic noise.
Nonvolatile Memory …, 2001
AbstractThis paper presents a design example that illustrates the potential of microelectromech... more AbstractThis paper presents a design example that illustrates the potential of microelectromechanical systems (MEMS) to perform the mechanical positioning required for addressing stored data and to enable an entirely new mechanism for reading and writing ...
IEEE Transactions on Magnetics, 2003
In this paper, we present an analysis of the performance of a 0.3-Tb/in 2 ultralow-power magnetic... more In this paper, we present an analysis of the performance of a 0.3-Tb/in 2 ultralow-power magnetic-forcemicroscopy-based scanning-probe storage device actuated by microelectromechanical systems technology. The device is currently under development at Carnegie Mellon University, Pittsburgh, PA. The analysis shows that, with an optimized commercial single-layered Co-based perpendicular medium with an optimized tip trajectory, a signal-to-noise ratio of 20-25 dB is achievable. The analysis includes general design considerations as well as various aspects of performance such as recording dynamics, 50 , intersymbol-interference limit, detection sensitivity, thermal degradation, intertrack interference, off-track errors, process variations, and surface fluctuation effect. Design/performance standards for the new device are suggested.
This paper presents a design example that illustrates the potential of microelectromechanical sys... more This paper presents a design example that illustrates the potential of microelectromechanical systems (MEMS) to perform the mechanical positioning required for addressing stored data and to enable an entirely new mechanism for reading and writing magnetic data. Specifically, MEMS sensors and actuators can be used to achieve active servo control of the separation between magnetic probe tips and a media surface with sub-nanometer accuracy.
In this research we have extensively analyzed and optimized the performance of MEMS-positioned, n... more In this research we have extensively analyzed and optimized the performance of MEMS-positioned, nonvolatile, re-writable, mass storage devices with MFM-based single-pole read/write magnetic tips currently under development at Carnegie Mellon University. This has been achieved through general design consideration investigation, analytical modeling, and through in-depth micromagnetic modeling and simulations. For micromagnetic modeling, two simulators were especially designed and built by the author to study and analyze the performance of the MFM-based MEMS-actuated mass storage device. The simulators have been tested and verified using the standard problem #1 proposed by the Micromagnetic Modeling Activity Group (muMAG) in the NIST Center for Theoretical and Computational Materials Science (CTCMS). In general design consideration investigation, many important concepts and observations have been developed. First, the tip field amplitude and gradient dependence on tip size has been stu...
2000 IEEE International Symposium on Circuits and Systems. Emerging Technologies for the 21st Century. Proceedings (IEEE Cat No.00CH36353), 2000
This paper addresses the design of an analog very large-scale integration (VLSI) high accuracy ne... more This paper addresses the design of an analog very large-scale integration (VLSI) high accuracy neural cell with supervised learning ability using standard 2-µm CMOS technology. A novel architecture is presented such that all cells, input, output, or hidden, have the same architecture which ensures a high degree of flexibility in terms of topology programming. Moreover, in designing the cell architecture, a new design technique based on hardware functionality multiplexing is employed. This technique resulted in a considerable compact cell. On the circuit level, the cell design is based mainly on a novel very high accuracy switched-current (SI) memory cell. With minor modifications, the SI memory cell is used in building all of the switched-current-based modules in the cell, which resulted in a high accuracy neural cell. The performance and timing for the separate modules and the whole cell are extensively studied. The cell is tested through a Multi-Layer Perceptron Network (MLP) using SPICE to solve the digit recognition problem.
IEEE Transactions on Semiconductor Manufacturing, 2000
In this paper, we present a novel methodology for fully characterizing back-end interconnect line... more In this paper, we present a novel methodology for fully characterizing back-end interconnect lines. The use of the proposed new hybrid resistive e-test and SEM imaging algorithm addresses several practical issues. First it overcomes the inaccuracy of back-end estimation based on full capacitive measurement due to neglecting sidewall slope. Depending on the sidewall slope, a significant error in the estimation of line width, line thickness, side line space, and ILD thickness can result. This impact is shown to increase as interconnect geometry scales down. Secondly, it accommodates the limited silicon area in test chips. Finally, in addition to systematic behavior, the methodology accurately estimates and re-produces random component to fully re-construct the behavior of the interconnects on actual Si.
IEEE Transactions on Magnetics, 2002
IEEE Transactions on Magnetics, 2004
In this work, we present three magnetic force microscopy (MFM)-compatible pulse-width-modulation ... more In this work, we present three magnetic force microscopy (MFM)-compatible pulse-width-modulation (PWM) coding scheme to be employed in scanning-probe storage devices. For each code, analytical models describing the code length utilization [CLU, i.e., non-return-to-zero (NRZ) code length to PWM code length ratio] and the signal-to-quantization noise ratio (SQNR) resulting from the granularity of the media are derived. To verify the models, a micromagnetic model was constructed. Using a proposed variable-length PWM coding scheme with 3 bits/symbol, 30-nm tip diameter, and a fractional step of 20% of the initial mark, a 82% increase in areal density over optimized regular NRZ single-bit coding is shown to be achievable (i.e., 1.26 Tb/in 2 ) with an SQNR of 17.2 dB and an overall SNR of 13.1 dB.
IEEE Transactions on Magnetics, 2003
In this paper, we present an analysis of the performance of a 0.3-Tb/in 2 ultralow-power magnetic... more In this paper, we present an analysis of the performance of a 0.3-Tb/in 2 ultralow-power magnetic-forcemicroscopy-based scanning-probe storage device actuated by microelectromechanical systems technology. The device is currently under development at Carnegie Mellon University, Pittsburgh, PA. The analysis shows that, with an optimized commercial single-layered Co-based perpendicular medium with an optimized tip trajectory, a signal-to-noise ratio of 20-25 dB is achievable. The analysis includes general design considerations as well as various aspects of performance such as recording dynamics, 50 , intersymbol-interference limit, detection sensitivity, thermal degradation, intertrack interference, off-track errors, process variations, and surface fluctuation effect. Design/performance standards for the new device are suggested.
IEEE Transactions on Magnetics, 2000
In this paper, we investigate the feasibility of using a magnetic force microscopy scheme for rec... more In this paper, we investigate the feasibility of using a magnetic force microscopy scheme for recording and retrieving magnetic marks for ultrahigh-density, ultralow power applications. We will address the main design considerations while designing such a system. Then, using the impulse-response and inverse-convolution technique, we deduce a novel tip trajectory for the optimum recording process. We will also apply extensive optimization for a Co x Cr y Pt 1 x y perpendicular media structure to maximize the signal-to-noise ratio (SNR). An areal density of up to 0.3 Tb in 2 is shown to be achievable with thermally stable magnetic marks and a SNR of 20-25 dB in the existence of additional electronic noise.
Nonvolatile Memory …, 2001
AbstractThis paper presents a design example that illustrates the potential of microelectromech... more AbstractThis paper presents a design example that illustrates the potential of microelectromechanical systems (MEMS) to perform the mechanical positioning required for addressing stored data and to enable an entirely new mechanism for reading and writing ...
IEEE Transactions on Magnetics, 2003
In this paper, we present an analysis of the performance of a 0.3-Tb/in 2 ultralow-power magnetic... more In this paper, we present an analysis of the performance of a 0.3-Tb/in 2 ultralow-power magnetic-forcemicroscopy-based scanning-probe storage device actuated by microelectromechanical systems technology. The device is currently under development at Carnegie Mellon University, Pittsburgh, PA. The analysis shows that, with an optimized commercial single-layered Co-based perpendicular medium with an optimized tip trajectory, a signal-to-noise ratio of 20-25 dB is achievable. The analysis includes general design considerations as well as various aspects of performance such as recording dynamics, 50 , intersymbol-interference limit, detection sensitivity, thermal degradation, intertrack interference, off-track errors, process variations, and surface fluctuation effect. Design/performance standards for the new device are suggested.