Author :
Ikeda, A. ; Travaly, Y. ; Humbert, A. ; Hoofman, R.J.O.M. ; Li, Y.-L. ; Tokei, Zs. ; Iacopi, F. ; Michelon, J. ; Bruynseraede, C. ; Willegems, M. ; Hendrickx, D. ; Van Aelst, J. ; Struyf, H. ; Versluijs, J. ; Heylen, N. ; Carbonell, L. ; Richard, O. ; Ben
Abstract :
Single damascene (SD) Cu/Aurorareg ULK interconnects with a minimum spacing of 50nm are achieved by using a metal hard mask (MHM) integration scheme, which enables to perform the resist ash before dielectric etch. This patterning scheme is used in combination with a low damage etch technique based on sidewall protection. Interconnect performance and reliability can be further improved by using Aurorareg ULK high modulus (HM), a low-k film with a reduced diffusivity as compared to Aurora ULK, and a comparable k-value of 2.7. The MHM approach results in a limited increase in integrated k-value by 0.1 for ULK HM vs. 0.3 for Aurorareg ULK. The median time dependent dielectric breakdown (TDDB) lifetime is well above the 10 years criterion for spacings down to the 50nm. Finally, the MHM integration scheme enabled fabrication of dual damascene interconnects with Aurorareg ULK HM
Keywords :
etching; integrated circuit interconnections; low-k dielectric thin films; masks; nanopatterning; 32 nm; 50 nm; Cu; ULK interconnect; damage etch technique; dielectric etch; integration process; interconnect scaling; low-k films; low-k property; metal hard mask; patterning scheme; single damascene; time dependent dielectric breakdown; Ash; Chemistry; Dielectric materials; Etching; Plasma applications; Plasma materials processing; Polymers; Protection; Resists; Strips;
