Browsing by Author "Chang, MH"

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A floating well method for exact capacitance-voltage measurement of nano technology
(2003-06-01)
Su, HD
;
Chiou, BS
;
Wu, SY
;
Chang, MH
;
Lee, KH
Small gate area with short gate length reduces the C-V distortion of ultrathin oxide devices, but results in high parasitic capacitance/total capacitance ratio. The floating well method can exclude the parasitic capacitance to obtain accurate inversion oxide thickness without using any dummy pattern. It is suitable for nano technology.
A synthesis of alpha-cuparenone based on symmetry considerations
(1997-06-01)
Ho, TL
;
Chang, MH
;
交大名義發表
;
應用化學系
;
National Chiao Tung University
A ring expansion approach to alpha-cuparenone was accomplished in 5 or 6 steps. The key intermediate is 3-methyl-3-(4-methylphenyl)cyclobutanone, which was derived from a [2+2]cycloaddition of dichloroketene on a styrene derivative, followed by dechlorination.
A synthesis of alpha-cuparenone based on symmetry considerations
(1997-06-01)
Ho, TL
;
Chang, MH
;
應用化學系
;
Department of Applied Chemistry
A ring expansion approach to alpha-cuparenone was accomplished in 5 or 6 steps. The key intermediate is 3-methyl-3-(4-methylphenyl)cyclobutanone, which was derived from a [2+2]cycloaddition of dichloroketene on a styrene derivative, followed by dechlorination.
Abnormal and regioselective Wacker oxidation of 1,5-dienes
(2003-09-01)
Ho, TL
;
Chang, MH
;
Chen, C
;
應用化學系
;
Department of Applied Chemistry
The presence of an additional double bond can change the regioselectivity of the Wacker oxidation of a 1-alkene moiety to give the aldehyde product. (C) 2003 Published by Elsevier Ltd.
Bi-mode breakdown test methodology of ultrathin oxide
(2003-12-01)
Su, HD
;
Chiou, BS
;
Ko, CY
;
Wu, SY
;
Chang, MH
The breakdown detections of ultrathin oxide (1.4-2 nm) using a fast voltage ramp have been studied. It was found that the breakdown voltage test of deep sub-micron technology requires the reduction of the gate area of test patterns and therefore the increase of the number of structures due to a large inversion gate current at a low electrical field (> 0. 1 A/cm(2) at 1 V) caused by the scaling down of oxide thickness. The gate current in accumulation mode is smaller than that in inversion mode by more than two orders of magnitude at a low applied voltage (1 V). The bi-mode model proposed in this paper applies a voltage stress in the inversion mode and detects failure in the accumulation mode to enhance the robustness of the breakdown test and reduce the possibility of pseudo breakdown failure. With the proposed method, a shorter test time with an increased test pattern area to improve the efficiency of the breakdown test of ultrathin oxide is achieved.
Characteristics of oxide breakdown and related impact on device of ultrathin (2.2 nm) silicon dioxide
(2003-09-01)
Su, HD
;
Chiou, BS
;
Wu, SY
;
Chang, MH
;
Lee, KH
The oxide breakdown characteristics of ultrathin oxide (2.2 nm) have been studied in this paper. Light emission microscopy (EMMI) analysis shows that each breakdown has a specific failure location with a random distribution. Gate leakage current increases for all soft breakdown events are similar. After soft breakdown, the I-V curve still shows the representative direct tunneling characteristics and can be fitted using a dual direct tunneling (DDT) model. Soft breakdown has no effect on the drain current of long-channel devices. Breakdown at the polyedge appears to be of the hard-breakdown mode and results in an abrupt increase in gate current. For short-channel devices, the polyedge is always within the damaged region of an oxide because the channel is shorter than the damaged region of the oxide. Hence, only hard breakdown resulting in permanent damage is observed in short-channel devices.
Early-late gate receiving for Bluetooth packet
(2001)
Peng, CS
;
Chang, MH
;
Wen, KA
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
An efficient early-late gate scheme for Bluetooth packet receiving had been proposed. It eliminates the use of Analog-to-Digital Converter (ADC) and expends only hundred gate counts to implement the timing recovery. Simulation with complete Bluetooth V1.0 baseband and radio specifications had been established to confirm the timing recovery algorithm. Field programmable gate arrays (FPGA) emulation and ASIC implementation had all been completed for performance analysis.
Improving Lamport one-time signature scheme
(2005-08-05)
Chang, MH
;
Yeh, YS
;
資訊科學與工程研究所
;
Institute of Computer Science and Engineering
One-time signature scheme, a kind of digital signature schemes, is used to sign at most one message; otherwise the signature can be forged. One of the advantages is that the one-time signature generation and verification are very efficient and it is useful for chip cards, where low computation complexity is required. Lamport first invented a one-time digital signature scheme based on one-way functions. However, the Lamport one-time scheme requires a large amount of space for storage of authentic information if a large number of messages are signed. In this paper, we improve the Lamport one-time signature on the amount of storage space for public keys and signed message saving storage space and propose an efficient scheme to sign a long message. Thus, we make the Lamport one-time signature useful in practice. (c) 2004 Elsevier Inc. All rights reserved.
Novel chip standby current prediction model and ultrathin gate oxide scaling limit
(2002-01-01)
Su, HD
;
Chiou, BS
;
Lu, PC
;
Chang, MH
;
Lee, KH
In deep sub-micron technology, leakage current of the oxide layer has a severe impact on chip power consumption due to the scaling down of oxide thickness. The inverter circuit model proposed in this paper provides a simple and quick method of predicting chip standby current. This model takes into account both the conventional device-off current and the inversion gate current, as compared to the conventional approach in which the gate leakage current is small and neglected. The temperature dependence study shows that the logarithm of the device-off current is inversely proportional to temperature. From 25 C, the device-off current increases tenfold for a temperature increase of 50 C, while the inversion gate current is almost temperature independent. Hence, a more aggressive oxide scaling rule could be employed in high-performance products operated at higher temperatures under the same device-off current/inversion gate current ratio.
Studies of stereocontrol in cyclization of hexacarbonyldicobalt-stabilized propargyl cations.
(1997-09-07)
Ho, TL
;
Chang, MH
;
應用化學系
;
Department of Applied Chemistry
Studies of stereocontrol in cyclization of hexacarbonyldicobalt-stabilized propargyl cations.
(1997-09-07)
Ho, TL
;
Chang, MH
;
應用化學系
;
Department of Applied Chemistry
Synthesis of cuparene and herbertene via a common intermediate
(1999-09-07)
Ho, TL
;
Chang, MH
;
應用化學系
;
Department of Applied Chemistry
A dihydroisobenzofuran (13) was obtained from beta-ionone in 10 steps via an intramolecular Diels-Alder reaction. On further oxidation, reductive ring opening and decarboxylation, cuparene and herbertene were synthesized.