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You searched on: Author: Yaw Obeng

Displaying records 1 to 10 of 29 records.
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1. Experimentally, How Does Cu TSV Diameter Influence its Stress State?
Published: 5/27/2015
Authors: Chukwudi Azubuike Okoro, Lyle E Levine, Yaw S Obeng, Ruqing Xu
Abstract: In this work, an experimental study of the influence of Cu through-silicon via (TSV) diameter on stress build up was performed using synchrotron-based X-ray microdiffraction technique. Three Cu TSV diameters were studied; 3 µm, 5 µm and 8 µm, all of ...

2. Electromagnetic Field Test Structure Chip for Back End of the Line Metrology
Published: 3/23/2015
Authors: Lin You, Jungjoon Ahn, Emily Hitz, Jonathon Michelson, Yaw S Obeng, Joseph J Kopanski
Abstract: 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 va ...

3. Influence of Metal¿MoS2 Interface on MoS2 Transistor Performance: Comparison of Ag and Ti Contacts
Published: 12/16/2014
Authors: 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
Abstract: 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 subth ...

4. Broad-Band Microwave-Based Metrology Platform Development: Demonstration of In-Situ Failure Mode Diagnostic Capabilities for Integrated Circuit Reliability Analyses
Published: 11/7/2014
Authors: Lin You, Chukwudi Azubuike Okoro, Jungjoon Ahn, Joseph J Kopanski, Yaw S Obeng, Rhonda R Franklin
Abstract: 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 t ...

5. Non-destructive Measurement of the Residual Stresses in Copper Through-Silicon Vias using Synchrotron Based Micro-beam X-ray Diffraction
Published: 7/1/2014
Authors: Chukwudi Azubuike Okoro, Lyle E Levine, Yaw S Obeng, Klaus Hummler, Ruqing Xu
Abstract: In this study, we report a new method for achieving depth resolved determination of the full stress tensor in buried Cu through-silicon vias (TSVs), using synchrotron based X-ray micro-diffraction technique. Two adjacent Cu TSVs were analyzed; on ...

6. Synchrotron-Based Measurement of the Impact of Thermal Cycling on the Evolution of Stresses in Cu Through-Silicon Via
Published: 6/30/2014
Authors: Chukwudi Azubuike Okoro, Lyle E Levine, Ruqing Xu, Klaus Hummler, Yaw S Obeng
Abstract: One of the main causes of failure during the lifetime of microelectronics devices is their exposure to fluctuating temperatures. In this work, synchrotron-based X-ray micro-diffraction is used to study the evolution of stresses in copper through-sili ...

7. Defect and Microstructural Evolution in Thermally Cycled Cu Through-Silicon Vias
Published: 6/14/2014
Authors: Chukwudi Azubuike Okoro, James Marro, Yaw S Obeng, Kathleen Richardson
Abstract: 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 ...

8. X-Ray Micro-Beam Diffraction Measurement of the Effect of Thermal Cycling on Stress in Cu TSV: A Comparative Study
Published: 5/26/2014
Authors: Chukwudi Azubuike Okoro, Lyle E Levine, Yaw S Obeng, Klaus Hummler, Ruqing Xu
Abstract: Microelectronic devices are subjected to constantly varying temperature conditions during their operational lifetime, which can lead to their failure. In this study, we examined the impact of thermal cycling on the evolution of stresses in Cu TSVs us ...

9. Microwave-Based Metrology Platform Development: Application of Broad-Band RF Metrology to Integrated Circuit Reliability Analyses
Published: 5/12/2014
Authors: Lin You, Chukwudi Azubuike Okoro, Jungjoon Ahn, Joseph J Kopanski, Yaw S Obeng
Abstract: In this paper we describe the development of a suite of techniques, based on the application of high frequency electromagnetic waves, to probe material and structural changes in integrated circuits under various external perturbations. We discuss how ...

10. Scanning Probe Microscopes for Subsurface Imaging
Published: 5/11/2014
Authors: Joseph J Kopanski, Lin You, Jungjoon Ahn, Emily Hitz, Yaw S Obeng
Abstract: 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 ...

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