Dominant factors in TDDB degradation of Cu interconnects

• Published in: IEEE transactions on electron devices Vol. 52; no. 8; pp. 1743 - 1750
• Main Author: Noguchi, J.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-08-2005; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Annealing; ANNEALING PROCESSES; Applied sciences; Breakdown; Chemical-mechanical polishing; CONNECTORS (ELECTRICAL); Copper; Design. Technologies. Operation analysis. Testing; Devices; DIELECTRIC BREAKDOWN; Dielectrics; Electric breakdown; Electric field strength; ELECTRONIC PRODUCTS; Electronics; Exact sciences and technology; Integrated circuit interconnections; Integrated circuit reliability; Integrated circuits; interface phenomena; INTERLAYERS; MECHANICAL POLISHING; Microelectronic fabrication (materials and surfaces technology); POLISHING; reliability; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; surface treatment; Interfacial layer; Annealing; Dielectric strength; Electric breakdown; Dielectric materials; Integrated circuit interconnections; Roughness; Durability; Surface treatment; dielectric breakdown; Time dependence; Interface phenomena; Microelectronic fabrication; Electric field; Wire bonding; Dielectric thin films; Reliability; Copper; Chemical mechanical polishing; Damaging
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2005.851849

The field acceleration factor (/spl gamma/) for the E-model of time-dependent dielectric breakdown (TDDB) in various Cu interconnect structures has been studied. The /spl gamma/ for pSiCN structures is larger than that of pSiN structures and independent of the kind of interlayer dielectric material or other processes used to make it. The relationship between the breakdown electric field strength (E/sub BD/) and the TDDB lifetime has been investigated. It has been demonstrated that the TDDB lifetime can be predicted from experimentally measured E/sub BD/ and /spl gamma/. An E/sub BD/ of at least 4.2 MV/cm is necessary to assure ten-year reliability under 0.2 MV/cm operation. Moreover, the important factors influencing the TDDB lifetime for Cu interconnects have been discussed. These include the Cu chemical-mechanical polishing (CMP), the post-CMP annealing, line edge roughness, and fine line effect.