Abslreet KAM ton are well known Io be that (finite!) pan of phase space in which the motion of a weakly F u r b e d classical Hamiltonian system remains integrable. M o w e r , they are tamers in Ihe phase space of systems with two d e w s of kedom. We show that elfain Hamiltonian syslems contain invariant noflm-plor fori with compressible flow. Using as an example an eledmn moving in elenromagnetic fields which are periodic in space we demonstrate: 0) that strange attractors (and repellers) of well known autonomous or (quasi-)pericdically timedliven systems may occur on such Strongr rOn; (ii) that one may 6nd boniss consisting of non-regular Hamiltonian tori in systems with any number of degrees of freedom (the flow on such barriers is non-chaotic, though); and Cii) Ihat certain RAM Ion transform into non-regular tori-rather Ihan breaking up-when the perturbation b e " s suong.03054470S'3420261+20$07.50 @ 1993 IOP Publishing Ud Lichtenberg A J and lieberman M A 1983 Regulnr and SIochastic Motion p " e w York Springer) Kaplan J Land Yorke J A 1919 Lccnue Notes m Mathematia 730 ed H 0 Peitgen and H 0 Wlfher Til T 1990 DimcIiom m Choos Ill ed Ha0 h i -t i n (Singapore: World Scientific) p 149

A robust embedded ladder-oxide (k ¼ 2:9)/copper (Cu) multilevel interconnect is demonstrated for 0.13 mm complementary metal oxide semiconductor (CMOS) generation. A stable ladder-oxide intermetal dielectric (IMD) is integrated by the Cu metallization with a minimum wiring pitch of 0.34 mm, and a single damascene (S/D) Cu-plug structure is applied. An 18% reduction in wiring capacitance is obtained compared with that in SiO 2 IMDs. The superior controllability of metal thickness by the S/D process enables us to enhance the MPU maximum frequency easily. The stress-migration lifetime of vias on wide metals for the S/D Cu-plug structure is longer than that for a dual damascene (D/D) structure. Reliability test results such as electromigration (EM), the temperature dependant dielectric breakdown (TDDB) of Cu interconnects, and pressure cooker test (PCT) results are acceptable. Moreover, a high flexibility in a thermal design is obtained.