[17]. As these
material reach their physical limit, devices cannot keep up with their performance. The Si02 reliability degrades as it
becomes thinner and result in breakdown [4]. Although Cu is less sensitive to electromigration than AI , the material is
more susceptible to open defect when used as interconnect
wires. Low-k materials utilized for back end process (e.g.
insulator between adjacent interconnect wires to minimize
cross talk) suffer from the high mechanical and thermal stress
during packaging phase.