AVS 47th International Symposium
    Manufacturing Science and Technology Wednesday Sessions
       Session MS-WeA

Paper MS-WeA5
Cluster Formation on Copper Evaporated Onto Dow Cyclotene 3022

Wednesday, October 4, 2000, 3:20 pm, Room 304

Session: Process Integration (Cu/Low-k/300mm)
Presenter: E. Sacher, Ecole Polytechnique, Canada
Authors: E. Sacher, Ecole Polytechnique, Canada
D.-Q. Yang, Ecole Polytechnique, Canada
S. Poulin, Ecole Polytechnique, Canada
S. Rodrigues, Ecole Polytechnique, Canada
L. Martinu, Ecole Polytechnique, Canada
M. Meunier, Ecole Polytechnique, Canada
Correspondent: Click to Email
Dow Cyclotene 3022 is a low permittivity polymer used in the microelectronics industry. It is made through the Diels-Alder polymerization of bis-benzocyclobutene-terminated divinyl siloxane monomers. Key Cu integration issues concern the adhesion of patterned Cu lines and the stability of the Cu-polymer interface to metal diffusion. Photoacoustic FTIR and XPS have shown that the Cu atoms interact asymmetrically with the aromatic rings of the Cyclotene to give weak bonding across the interface. XPS, XRD, AFM, TEM, spectroscopic ellipsometry, and other techniques, have shown that the Cu exists in the form of surface clusters. TEM micrographs, for example, show that a nominal 3.2 nm deposit exists in the form of irregular clusters with an average diameter estimated at 9 nm. This may be compared with an XPS estimate, based on an intensity comparison at two different orbital energies, which suggests that the clusters are spherical and about 7 nm in size. The weak bonding permits surface diffusion, which causes cluster coalescence on annealing, although there is no evidence, from any technique available to us, of diffusion into the bulk Cyclotene. The structure and properties of the Cu/Cyclotene interface will be compared with adhesion studies by microscratch and adhesive tape peel tests.