Browsing by Author "Chen, HB"

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Novel dual-metal gate technology using Mo-MoSix combination
(2006-06-01)
Li, TL
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Ho, WL
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Chen, HB
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Wang, HCH
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Chang, CY
A novel dual-metal gate technology that uses a combination of Mo-MoSix gate electrodes is proposed. An amorphous-Si/Mo stack was fabricated as a gate electrode for the n-channel device. It was thermally annealed to form MoSix. Pure Mo served as the gate electrode for the p-channel device. The work functions of MoSix and pure Mo gates on SiO2 are 4.38 and 4.94 eV, respectively, which are appropriate for devices with advanced transistor structures. The small increase in the work function (< 20 meV) and the negligible equivalent oxide thickness variation (< 0.08 nm) after rapid thermal annealing at 950 degrees C for 30 s also demonstrate the excellent thermal stabilities of Mo and MoSix on SiO2. Additional arsenic ion implantation prior to silicidation was demonstrated further to lower the work function of MoSix to 4.07 eV. This approach for modulating the work function makes the proposed combination of Mo-MoSix gate electrodes appropriate for conventional bulk devices. The developed dual-metal-gate technology on HfO2 gate dielectric was also evaluated. The effective work functions of pure Mo and undoped MoSix gates on HfO2 are 4.89 and 4.34 eV, respectively. A considerable work-function shift was observed on the high-k. gate dielectric. The effect of arsenic preimplantation upon the work function of the metal silicide on HfO2 was also demonstrated, even though the range of modulation was a little reduced.
On multicast rearrangeable 3-stage Clos networks without first-stage fan-out
(2006)
Chen, HB
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Hwang, FK
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應用數學系
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Department of Applied Mathematics
For the multicast rearrangeable 3-stage Clos networks where input crossbars do not have fan-out capability, Kirkpatrick, Klawe, and Pippenger gave a sufficient condition and also a necessary condition which differs from the sufficient condition by a factor of 2. In this paper, we first tighten their conditions. Then we propose a new necessary condition based on the a. ne plane such that the necessary condition matches the sufficient condition for an infinite class of 3-stage Clos networks.
One-dimensional optimal bounded-shape partitions for Schur convex sum objective functions
(2006-05-01)
Chang, FH
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Chen, HB
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Guo, JY
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Hwang, FK
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Rothblum, UG
Consider the problem of partitioning n nonnegative numbers into p parts, where part i can be assigned n(i) numbers with n(i) lying in a given range. The goal is to maximize a Schur convex function F whose ith argument is the sum of numbers assigned to part i. The shape of a partition is the vector consisting of the sizes of its parts, further, a shape (without referring to a particular partition) is a vector of nonnegative integers (n(1),..., n(p)) which sum to n. A partition is called size-consecutive if there is a ranking of the parts which is consistent with their sizes, and all elements in a higher-ranked part exceed all elements in the lower-ranked part. We demonstrate that one can restrict attention to size-consecutive partitions with shapes that are nonmajorized, we study these shapes, bound their numbers and develop algorithms to enumerate them. Our study extends the analysis of a previous paper by Hwang and Rothblum which discussed the above problem assuming the existence of a majorizing shape.