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Search Publications by: Yaw S. Obeng (Fed)

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Displaying 51 - 75 of 86

Electromagnetic Field Test Structure Chip for Back End of the Line Metrology

March 23, 2015
Author(s)
Lin You, Jungjoon Ahn, Emily Hitz, Jonathon Michelson, Yaw S. Obeng, Joseph J. Kopanski
A test chip to produce known and controllable gradients of surface potential and magnetic field at the chip surface and suitable for imaging with various types of scanning probe microscopes is presented. The purpose of the test chip is to evaluate various

Influence of Metal?MoS2 Interface on MoS2 Transistor Performance: Comparison of Ag and Ti Contacts

December 16, 2014
Author(s)
Hui H. Yuan, Guangjun Cheng, Lin You, Haitao Li, Hao Zhu, Wei Li, Joseph J. Kopanski, Yaw S. Obeng, Angela R. Hight Walker, David J. Gundlach, Curt A. Richter, D. E. Ioannou, Qiliang Li
In this work, we present a study of enhancing MoS2 transistor performance by using proper metal contact. We found that the on-state current of MoS2 field-effect transistors with 30 nm Au/ 30 nm Ag contacts is enhanced more than 60 times and the

Broad-Band Microwave-Based Metrology Platform Development: Demonstration of In-Situ Failure Mode Diagnostic Capabilities for Integrated Circuit Reliability Analyses

November 7, 2014
Author(s)
Lin You, Chukwudi A. Okoro, Jungjoon Ahn, Joseph Kopanski, Yaw S. Obeng, Rhonda R. Franklin
In this paper, we discuss the use of broadband high frequency electromagnetic waves (RF) to non- destructively identify, classify and characterize performance-limiting defects in emerging nanoelectronic devices. As an illustration, the impact of thermal

Defect and Microstructural Evolution in Thermally Cycled Cu Through-Silicon Vias

June 14, 2014
Author(s)
Chukwudi A. Okoro, James Marro, Yaw S. Obeng, Kathleen Richardson
In this study, the effect of thermal cycling on defect generation, microstructure, and the RF signal integrity of blind Cu through-silicon via (TSV) were investigated. Three different thermal cycling profiles were used; each differentiated by their peak

Scanning Probe Microscopes for Subsurface Imaging

May 11, 2014
Author(s)
Joseph J. Kopanski, Lin You, Jungjoon Ahn, Emily Hitz, Yaw S. Obeng
Scanning probe microscopes (SPMs) have some ability to image sub-surface structures. This paper describes the theoretical and practical basis for imaging metal lines buried beneath insulating layers and for imaging insulating regions or voids within metal

Development of a Methodology to Determine Risk of Counterfeit Use

June 5, 2013
Author(s)
Mark Schaffer, Yaw S. Obeng
Counterfeit components have become a multi-million dollar, yet undesirable, part of the electronics industry. The profitability of the counterfeit industry rests in large part on its ability to recognize supply constraints and quickly respond, effectively

Accelerated Stress Test Assessment of Through-Silicon Vias Using RF Signals

June 1, 2013
Author(s)
Chukwudi A. Okoro, Pavel Kabos, Jan Obrzut, Klaus Hummler, Yaw S. Obeng
In this work, radio frequency (RF) signal is demonstrated as an effective metrology tool for the assessment of the effect of thermal cycling on the reliability of through-silicon via (TSV) stacked dies. It was found that RF signal integrity of TSV daisy

Use of RF-Based Technique as a Metrology Tool for TSV Reliability Analysis

May 28, 2013
Author(s)
Chukwudi A. Okoro, Yaw S. Obeng, Jan Obrzut, Pavel Kabos, Klaus Hummler
In this work, we used radio frequency (RF) based measurement technique is used as a prognostic tool for the assessment of the effect of thermal cycling on the reliability of through-silicon via (TSV) stacked dies. It was found that RF signal integrity in

X-Ray Micro-Beam Diffraction Determination of Full Stress Tensors in Cu TSVs

May 28, 2013
Author(s)
Chukwudi A. Okoro, Lyle E. Levine, Oleg A. Kirillov, Yaw S. Obeng, Ruqing Xu, Jonathan Z. Tischler, Wenjun Liu, Klaus Hummler
We report the first non-destructive, depth resolved determination of the full stress tensor in Cu through-silicon vias (TSVs), using synchrotron based micro-beam X-ray diffraction. Two adjacent Cu TSVs were studied; one deliberately capped with SiO2, the

Measurement Science for "More-Than-Moore" Technology Reliability Assessments

October 12, 2012
Author(s)
Chukwudi A. Okoro, Jungjoon Ahn, Meagan V. Kelso, Pavel Kabos, Joseph Kopanski, Yaw S. Obeng
In this paper, we will present an overview of metrology issues and some of the techniques currently under development in our group at NIST, aimed at understanding some of the potential performance limiting issues in such highly integrated systems. We will

Metrology for Nanosystems and Nanoelectronics Reliability Assessments

August 20, 2012
Author(s)
Yaw S. Obeng, Chukwudi A. Okoro, Joseph J. Kopanski
The traditional models and techniques for studying reliability in integrated circuits may not be appropriate for nanoelectronics and nanosystems. In this paper, we present an overview of a number of materials and metrology techniques currently under

A Case Study on the Impact of Local Material Chemistry on the Mechanical Reliability of Packaged Integrated Circuits: Correlation of the Packaging Fallout to the Chemistry of Passivation Dielectrics in an Al-Cu System

March 19, 2012
Author(s)
Chukwudi A. Okoro, Yaw S. Obeng
In this paper, we use a variety of analytical techniques to examine the impact of local chemistry, and the mechanical properties, of the encapsulation dielectric films on the post-packaging device rejection rate of integrated circuit devices. A strong

Towards clean and crackless transfer of graphene

January 2, 2012
Author(s)
Xuelei X. Liang, Brent A. Sperling, Irene G. Calizo, Guangjun Cheng, Christina Hacker, Qin Zhang, Yaw S. Obeng, Kai Yan, Hailin Peng, Qiliang Li, Xiaoxiao Zhu, Hui Yuan, Angela R. Hight Walker, Zhongfan Liu, Lianmao Peng, Curt A. Richter
We present the results of a thorough study of wet chemical methods for transferring chemical vapor deposition grown graphene from the metal growth substrate to a device compatible substrate. Based on these results, we have developed a "modified RCA clean"

The Case for Innovations in Photovoltaics: the Nonmaterial Edge

January 26, 2011
Author(s)
Yaw S. Obeng, Kathleen C. Richardson
The limitations of current thin film and the gaps to cost efficient photovoltaic (PV) cells will be discussed in the presentation. This discussion will suggest ways to improve PV cell performance through the use of reduced dimension materials (e.g