Reliability evaluation of tungsten donut-via as an element of the highly robust metallization. (September 2016)

• Record Type: Journal Article
• Authors: Hein, Verena; Erstling, Marco; Sethu, Raj Sekar; Weide-Zaage, Kirsten; Bai, Tianlin
• Is Part Of: Microelectronics and reliability. Volume 64(2016)
• Page Start: 259
• Page End: 265
• Publication Date: 2016-09
• Subjects: Donut-via -- Interconnect reliability -- Design -- Robustness -- High temperature -- AlCu-metallization; Electronic apparatus and appliances -- Reliability -- Periodicals; Miniature electronic equipment -- Periodicals; Appareils électroniques -- Fiabilité -- Périodiques; Équipement électronique miniaturisé -- Périodiques; Electronic apparatus and appliances -- Reliability; Miniature electronic equipment; Periodicals; 621.3815
• DOI: 10.1016/j.microrel.2016.07.136
• Languages: English
• ISSNs: 0026-2714

Abstract

Abstract: The typical via layout in CMOS technology with AlCu-metallizations and tungsten via is cylindrical. Common vias have a size as small as possible in the related process. More challenging application, temperature and mission profiles require higher robustness of a metallization [1, 2]. Via arrays of small common vias are in use to the transfer of higher currents [3]. But the typical via array layout is not the best layout for applications which are faced to high mechanical stress because via arrays metal layer connections make these parts in the stack inflexible. The developed so called highly robust metallization is optimized for applications with extended operating conditions regarding higher currents and temperatures as well as mechanical stress [4]. Donut-Vias are elements of the highly robust metallization for the interconnection of highly robust metal lines. The paper shows the layout of a Donut-Via and explains the benefits and limits of the new layout by simulation and test results. Highlights: Excellent performance for Donut-Via in highly robust metallization stack Improved local mechanical stress distribution