Channeling crack of low-k dielectric films

EM 397 Term Paper:
Kuan H. Lu
Channeling crack of low-k dielectric films
Today low-k dielectric materials are integrated into computer chips to improve the
operation speed and reduce the cross-talk noise. Due to weak mechanical properties of
low-k dielectric materials, cohesive failure is subjected to occur. Channel cracking is
one common mode of cohesive failure. In this term paper, several potential issues
relevant to channel cracking of low-k dielectric thin films are reviewed. These issues
include the well known substrate constrain effect; the concentration of crack driving
force due to patterned structure, as shown in the following figure, and the degrading
of fracture toughness as scaling down the dielectric constant of the films. Some design
rules of applying the low-k dielectric thin films are also discussed in this report.
1. X. H. Liu, “Channel cracking in low-k films on patterned multi-layers”,
Proceedings of the IEEE 2004 International Interconnect Technology Conference,
page 93-95.
2. E. G. Liniger, “Moisture-driven crack growth in blanket low dielectric constant
and ultralow dielectric constant films”, Journal of Applied Physics, 96, 2004.