Yuhong Zheng

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Control of variability and performance in the back end of the VLSI manufacturing line has become extremely difficult with the introduction of new materials such as copper and low-k dielectrics. To improve manufacturability, and in particular to enable more uniform chemical-mechanical planarization (CMP), it is necessary to insert area fill features into(More)
BACKGROUND Human embryonic stem cell (hESC) lines derived from poor quality embryos usually have either normal or abnormal karyotypes. However, it is still unclear whether their biological characteristics are similar. METHODS Seven new hESC lines were established using discarded embryos. Five cell lines had normal karyotype, one was with an unbalanced(More)
Control of variability and performance in the back end of the VLSI manufacturing line has become extremely difficult with the introduction of new materials such as copper and low-k dielectrics. Uniformity of chemical-mechanical planarization (CMP) requires the insertion of area fill features into the layout, in order to smoothen the variation of feature(More)
In recent years many common applications have been modified to take advantage of modern cryptography algorithms to enhance security in Internet communications. This paper presents an overview of several widely used secure Internet services, such as remote login, file transfer and domain name resolution applications. Trace data is used to derive measurements(More)
A new Open Artwork System Interchange Standard (OASIS) has been recently proposed for replacing the GDSII format. A primary objective of the new OASIS format is to enhance the compressibility of layout data. We compare the data compression capability of the Full OASIS set of operators with those also present in GDSII, which we refer to as the Restricted(More)
  • Robert B Ellis, In Mathematics, Andrew B Kahng, R J N B Cooper, A B Ellis, Kahng +35 others
  • 2012
Teaching Assistant, Virginia Tech. Lecturer with full responsibility for two courses totaling three lecture sections. Teaching assistant, and tutor, each for one semester. Types of Results Bounds on and exact values for optimal sizes of adaptive error-correcting and covering codes, channel generalizations and asymptotic bounds, near-perfect adaptive codes,(More)
Dummy fill is introduced into sparse regions of a VLSI layout to equalize the spatial density of the layout, improving uniformity of chemical-mechanical planarization (CMP). It is now well-known that dummy fill insertion for CMP uniformity changes the back-end flow with respect to layout, parasitic extraction and performance analysis. Of equal import is(More)
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