Time filter

Source Type

Seoul, South Korea

Kim Y.,Microsystems Packaging Center | Um J.,Seoul National University of Science and Technology | Kim S.,Seoul National University of Science and Technology | Kim S.E.,Seoul National University of Science and Technology
ECS Solid State Letters | Year: 2012

The p-type to n-type conductivity inversion of SnO thin films was demonstrated through nitrogen incorporation via reactive RF sputtering. The undoped SnO thin film showed a relatively low p-type conductivity of 0.05 Ω-1cm-1 and it was lowered slightly to 0.04 Ω-1cm-1 with nitrogen incorporation. Then the SnO thin films exhibited the n-type conductivity of 79.97 Ω -1cm-1 as the nitrogen incorporation was increased. The undoped SnO thin film consisted of a polycrystalline SnO phase with a preferred (101) orientation; however, with nitrogen incorporation, the preferred orientation was suppressed, and the SnO thin films became nanocrystalline. © 2012 The Electrochemical Society. All rights reserved.

Maeng K.-H.,Seoul National University of Science and Technology | Kim Y.,Microsystems Packaging Center | Kang S.-G.,Microsystems Packaging Center | Kim S.-D.,Microsystems Packaging Center | And 2 more authors.
Current Applied Physics | Year: 2011

In 3D wafer-stacking technology, one of the major manufacturing issues is wafer warpage because it causes process and product failures, such as delamination, cracking, mechanical stresses, and even electrical failure. In this study, the wafer warpage and local strain of thinned Si wafers in a wafer stack were investigated. A blanket Cu film was deposited on a Si wafer by a sputtering process. Two Cu deposited wafers were bonded by a thermo-compression method, and a stacked wafer was thinned down to 30 μm. The three wafers were then stacked on a Si wafer substrate. The wafer warpage and local strain of each stacked Si wafer were measured by film-stress measurement and the convergent-beam electron diffraction technique of transmission electron microscopy, respectively. An emphasis was placed on the effects of wafer stacking by Cu bonding and Si thinning on stress development in a thinned Si wafer. As the number of wafers in a stack increased, wafer warpage became severe, and the local strain in thinned Si wafers near the Si/Cu interface was increased. © 2011 Elsevier B.V. All rights reserved.

Discover hidden collaborations