Hillock formation during electromigration in Cu （丘在铜电迁移形成）.pdfVIP

Hillock formation during electromigration in Cu and Al thin films: Three-dimensional grain growth A. Gladkikh and Y. Lereah Department of Electronic Devices and Materials, Tel Aviv University, Ramat Aviv, Israel 69978 E. Glickman Graduate School of Applied Science and Technology, The Hebrew University, Jerusalem, Israel 91904 M. Karpovskia) and A. Palevski School of Physics and Astronomy, Tel Aviv University, Ramat Aviv, Israel 69978 J. Schubert Intel, Jerusalem, Israel 91031 Received 18 August 1994; accepted for publication 19 December 1994 The evolution of microstructure in Al and Cu thin film lines during electromigration has been studied using a transmission electron microscopy. Grain boundary migration was found to be critically involved in the electromigration induced hillock formation that can be described as a three-dimensional growth of a single grain. © 1995 American Institute of Physics. Electromigration EM damage in metal interconnection representation of the damaged areas. In Fig. 2a the region lines is a serious problem in the microelectronic industry. Al of increased film thickness hillock is clearly seen the is the most commonly used as an interconnect material; and thicker region is darker due to the absorption contrast. The Cu is considered to be the most promising alternative for hillock covers a group of several adjacent grains grains 1, 2, Al.1–4 Recent observations show that the Cu lines may suffer 3, and 4. We have analyzed the hillock structure using a from the same EM reliability problem as the Al ones.5–8 The goniometer stage which allowed to bring Bragg angle each goal of our work was to rev