Browsing by Author "Liao, YY"

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A novel erase scheme to suppress overerasure in a scaled 2-bit nitride storage flash memory cell
(2004-09-01)
Yeh, CC
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Wang, TH
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Tsai, WJ
;
Lu, TC
;
Liao, YY
The cause of over-erasure in a two-bit nitride storage Flash memory cell is investigated. Extra positive charges accumulated above the n(+) unction and channel-shortening enhanced drain-induced barrier lowering effect are found to be responsible for threshold voltage (V-t) lowering in an over-erased cell. A modified erase scheme is proposed to resolve this issue. By applying a source voltage during erase, the erase speed can be well controlled for cells with different channel lengths and a wide range of program-state Vt distribution, which will reduce overerasure significantly.
A novel fully CMOS process compatible PREM for SOC applications
(2005-03-01)
Yeh, CC
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Wang, TH
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Tsai, WJ
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Lu, TC
;
Liao, YY
A novel nonvolatile memory cell named programmable resistor with eraseless memory (PREM) is proposed for system on chip applications for the first time. PREM combines a novel "eraseless" algorithm and the progressive breakdown of an ultrathin oxide. No or one extra mask is needed with a standard CMOS process. Multitime programming, multilevel cell, nonvolatility, and low-voltage operation are realized. Good reliability is demonstrated based on the result of a single cell.
A novel PHINES flash memory cell with low power program/erase, small pitch, two-bits-per-cell for data storage applications
(2005-04-01)
Yeh, CC
;
Wang, TH
;
Tsai, WJ
;
Lu, TC
;
Chen, MS
A novel programming by hot-hole injection nitride electron storage (PHINES) Flash memory technology is-developed. The memory bit size of 0.046 mu m(2) is fabricated based on 0.13-mu m technology. PHINES cell uses a nitride trapping storage cell structure. Fowler-Nordheim (FN) injection is performed to raise V-t in erase while programming is done by lowering a local V-t through hand-to-hand tunneling-induced hot hole (BTBT HH) injection. Two-bits-per-cell feasibility, low-power and high-speed program/erase, good endurance and data retentivity make it a promising candidate for Flash EEPROM technology in gigabit era applications.
Alignment and orientation of absorbed dipole molecules
(2004-12-01)
Liao, YY
;
Chen, YN
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Chuu, DS
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電子物理學系
;
Department of Electrophysics
Half-cycle laser pulse is applied on an absorbed molecule to investigate its alignment and orientation behavior. Crossover from field-free to hindered rotation motion is observed by varying the angel of hindrance of potential well. At small hindered angle, both alignment and orientation show sinusoidal-like behavior because of the suppression of higher excited states. However, mean orientation decreases monotonically as the hindered angle is increased, while mean alignment displays a minimum point at certain hindered angle. The reason is attributed to the symmetry of wave function and can be explained well by analyzing the coefficients of eigenstates.
IAC network for composition of waste-incineration facility
(1996-04-01)
Kao, JJ
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Liao, YY
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環境工程研究所
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Institute of Environmental Engineering
This research explores a prototypical interactive activation and competition (IAC) network to facilitate the selection of an appropriate facility combination for municipal solid waste incineration on the basis of characteristics of waste streams. Waste of types treatable with a specific facility combination was also evaluated. A prototypical IAC network was developed with a knowledge base constructed from five data sources: waste characteristics, air-pollution-control devices, pretreatment units, flue gas cooling types, and combustion-chamber types. Unlike a traditional database or a rule base, questions with incomplete information can be answered by the IAC network. This advantage greatly helps an engineer screen a sound facility combination for a specified waste stream with some degree of uncertainty. The prototype can be used also by a waste authority to preliminarily evaluate waste facility construction permit applications, by a novice engineer to learn the appropriate usage of a facility, and by an incinerator manager to preliminarily evaluate treatable waste.
Orientation of adsorbed dipolar molecules: A conical well model
(2006-03-01)
Liao, YY
;
Chen, YN
;
Chou, WC
;
Chuu, DS
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電子物理學系
Orientation of single and two coupled polar molecules irradiated by a single laser pulse under a conical-well model is investigated theoretically. The orientation of a single hindered rotor shows a periodic behavior. In particular, the amplitude of the oscillation is sensitive to the degree of alternation of the laser field. Crossover from field-free to hindered rotation is observed by varying the hindering angle for different heights of conical wells. For a small hindering potential and angle, time-averaged orientation differs greatly from that for an infinite one. The orientation at a large hindering angle shows irregularlike behavior under strong dipole-dipole interaction. Entanglement induced by the dipole-dipole interaction is also calculated for the coupled-rotor system, in which the time-averaged entropy increases monotonically as the hindering angle is increased. The competition between the confinement effect and dipole interaction is found to dominate the behavior of the coupled-rotor system.
Orientations of two coupled molecules
(2004-11-11)
Liao, YY
;
Chen, YN
;
Chuu, DS
;
電子物理學系
;
Department of Electrophysics
Orientation states of two coupled polar molecules controlled by laser pulses are studied theoretically. By varying the period of a series of periodically applied laser pulse, transition from regular to chaotic behavior may occur. Schmidt decomposition is used to measure the degree of entanglement. It is found that the entanglement can be enhanced by increasing the strength of laser pulse. (C) 2004 Elsevier B.V. All rights reserved.
Rotational entangled states between two coupled molecules
(2006-01-28)
Liao, YY
;
Chen, YN
;
Li, CM
;
Chuu, DS
;
電子物理學系
A method is proposed to create entanglement between two coupled identical polar molecules separated at a distance of tens of nanometres. Entangled states of two coupled polar molecules controlled by half-cycle pulses are studied theoretically. The von Neumann entropy is calculated to characterize the degree of entanglement. By varying the pulse shape of the applied laser, transition from regular to irregular behaviour occurs. Moreover, the entanglement is also found to be enhanced by applying multiple laser pulses. The behaviour from quantum to classical limit is also discussed.
Rotational states of an adsorbed dipole molecule in an external electric field
(2003-08-15)
Shih, YT
;
Liao, YY
;
Chuu, DS
;
電子物理學系
;
Department of Electrophysics
The rotational states of an adsorbed dipole molecule in an external electric field were investigated. The surface hindering potential was modeled as a finite conical well and a dipole-field interaction was added to the hindering potential. The molecular wave functions were expressed in terms of the eigenfunctions of molecular hindered rotation in the absence of electric field. Eigenenergies were determined by the matrix diagonalization procedures. Our results showed that, for both vertically and horizontally adsorbed molecules, there is avoided crossing between two adjacent rotational energy levels, as the field strength is increased, and finally all state energies decrease rapidly as the field strength is strong enough. The avoided crossing is due to the redistribution of wave function between different potential well regions. By employing the sudden unhindrance approximation, the rotational-state distributions of molecules desorbing from a solid surface in the presence of external electric field were calculated. Our results showed that the rotational-state distributions are significantly influenced by the external electric field. Since the electric field increases the ground-state energy of adsorbed molecule, the distribution shifts towards the high-J region if the electric field is applied to orient the molecular axis against the molecular preferred orientation. On the contrary, the distribution shifts towards the low-J region if the electric field is applied to orient the molecular axis towards molecular preferred orientation because the electric field decreases the ground-state energy of adsorbed molecule. The solutions to the finite conical well were also used to calculate the rotational alignment in the photodesorption of CO from Cr2O3(0001). Our results showed that at low-J values the CO molecules desorb like a helicopter, while at high-J values a cartwheel-like motion is preferred. This result is in qualitative agreement with the experimental observation.
Spin relaxation in a GaAs quantum dot embedded inside a suspended phonon cavity
(2006-02-01)
Liao, YY
;
Chen, YN
;
Chuu, DS
;
Brandes, T
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電子物理學系
The phonon-induced spin relaxation in a two-dimensional quantum dot embedded inside a semiconductor slab is investigated theoretically. An enhanced relaxation rate is found due to the phonon van Hove singularities. Oppositely, a vanishing deformation potential may also result in a suppression of the spin relaxation rate. For larger quantum dots, the interplay between the spin orbit interaction and Zeeman levels causes the suppression of the relaxation at several points. Furthermore, a crossover from confined to bulklike systems is obtained by varying the width of the slab.