Chenming Hu

Bio: Chenming Hu is an academic researcher from University of California, Berkeley. The author has contributed to research in topics: MOSFET & Gate oxide. The author has an hindex of 119, co-authored 1296 publications receiving 57264 citations. Previous affiliations of Chenming Hu include Motorola & National Chiao Tung University.

A capacitance method to determine the gate-to-drain/Source overlap length of MOSFET's

Abstract: A method is described which uses accurate measurement of gate-to-drain/source overlap capacitances to determine the gate-to-drain/ source overlap length for process control as well as device characterization. The method might also be a useful analytical tool in studying lateral dopant diffusion. Using this technique, the variation in overlap length of MOSFET's in a 4-in wafer is mapped. It is found that a significant spread of the overlap exits and is attributable to the implant shadowing by the polysilicon gate.

A ferroelectric DRAM cell for high density NVRAMs

Abstract: The operation of a ferroelectric memory cell for nonvolatile random access memory (NVRAM) applications is described. Because ferroelectric polarization reversal only occurs during store/recall but not DRAM read/write, ferroelectric fatigue is not a serious endurance problem. In the worst case, the effective silicon dioxide thickness of the unoptimized film studied here is less than 15 A. The resistivity and endurance properties of the ferroelectric films can be optimized by modifying the composition of the film. This cell can be the basis of a very high density nonvolatile RAM with practically no read/write cycle limit and at least 1010 nonvolatile store/recall cycles

Modeling and design study of nanocrystal memory devices

Abstract: Semiconductor memory for the future demand high density/low cost and low power consumption cell design. Compared with DRAM, flash memory with floating gate structure consume less power and they can also achieve much high array density. However, the tunnel oxide must be less than 25 A in order to achieve 100 ns write/erase time for a reasonable programming voltage (<10 V). Unfortunately, the retention time of a floating-gate device with 20 A tunnel oxide is less than 1 ms. To achieve a better retention/programming time ratio, a semiconductor memory with nanocrystal embedded in the gate dielectric was proposed. Although a nanocrystal memory device has been experimentally investigated, no theory is available to guide its design or to predict its performance limits, especially the nanocrystal size scaling limit. In this paper, the write/erase and retention time of semiconductor nanocrystal memory devices at room temperature are modeled using single-charge tunneling theory with quantum confinement and Coulomb blockade effects. The impact of nanocrystal size and tunnel-oxide thickness are studied, and the suitability of nanocrystal memory devices for nonvolatile memory and DRAM applications is discussed.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

High-κ gate dielectrics: Current status and materials properties considerations

Abstract: Many materials systems are currently under consideration as potential replacements for SiO2 as the gate dielectric material for sub-0.1 μm complementary metal–oxide–semiconductor (CMOS) technology. A systematic consideration of the required properties of gate dielectrics indicates that the key guidelines for selecting an alternative gate dielectric are (a) permittivity, band gap, and band alignment to silicon, (b) thermodynamic stability, (c) film morphology, (d) interface quality, (e) compatibility with the current or expected materials to be used in processing for CMOS devices, (f) process compatibility, and (g) reliability. Many dielectrics appear favorable in some of these areas, but very few materials are promising with respect to all of these guidelines. A review of current work and literature in the area of alternate gate dielectrics is given. Based on reported results and fundamental considerations, the pseudobinary materials systems offer large flexibility and show the most promise toward success...

Design of Analog CMOS Integrated Circuits

Abstract: The CMOS technology area has quickly grown, calling for a new text--and here it is, covering the analysis and design of CMOS integrated circuits that practicing engineers need to master to succeed. Filled with many examples and chapter-ending problems, the book not only describes the thought process behind each circuit topology, but also considers the rationale behind each modification. The analysis and design techniques focus on CMOS circuits but also apply to other IC technologies. Table of contents 1 Introduction to Analog Design 2 Basic MOS Device Physics 3 Single-Stage Amplifiers 4 Differential Amplifiers 5 Passive and Active Current Mirrors 6 Frequency Response of Amplifiers 7 Noise 8 Feedback 9 Operational Amplifiers 10 Stability and Frequency Compensation 11 Bandgap References 12 Introduction to Switched-Capacitor Circuits 13 Nonlinearity and Mismatch 14 Oscillators 15 Phase-Locked Loops 16 Short-Channel Effects and Device Models 17 CMOS Processing Technology 18 Layout and Packaging

Prospects of Colloidal Nanocrystals for Electronic and Optoelectronic Applications

Abstract: Nanocrystals (NCs) discussed in this Review are tiny crystals of metals, semiconductors, and magnetic material consisting of hundreds to a few thousand atoms each. Their size ranges from 2-3 to about 20 nm. What is special about this size regime that placed NCs among the hottest research topics of the last decades? The quantum mechanical coupling * To whom correspondence should be addressed. E-mail: dvtalapin@uchicago.edu. † The University of Chicago. ‡ Argonne National Lab. Chem. Rev. 2010, 110, 389–458 389