AVS 47th International Symposium
    Incorporating Principles of Industrial Ecology Wednesday Sessions
       Session IE+PS+MS+SE-WeM

Invited Paper IE+PS+MS+SE-WeM1
CVD Films as Directly Patternable Low-k Dielectrics

Wednesday, October 4, 2000, 8:20 am, Room 304

Session: Environmentally Friendly Process Development
Presenter: K.K. Gleason, Massachusetts Institute of Technology
Authors: K.K. Gleason, Massachusetts Institute of Technology
H.G. Pryce Lewis, Massachusetts Institute of Technology
G.L. Weibel, Cornell University
C.K. Ober, Cornell University
Correspondent: Click to Email
As microelectronic feature sizes decrease to 100-nm and below, major advances in both interconnect and lithographic technologies are necessary. Novel low-k candidates being assessed include fluorine- and silicon-containing materials produced by chemical vapor deposition (CVD). Fluorine- and silicon-containing polymeric materials are also ideal resist candidates for 157-nm photolithography, as conventional photoresists are opaque at this wavelength. In this paper, we present a collaboration aimed at merging the role of sacrificial resist and low-k dielectric. Specifically, we are investigating a direct dielectric patterning process in which a low-k fluorocarbon or organosilicon material is deposited by CVD, exposed, and developed using no wet processing. In our scheme, a film is deposited using hot-filament CVD, a non-plasma technique which offers the ability to tailor film chemistries. The film is masked and exposed using e-beam or a 157-nm source, and developed using supercritical CO@sub 2@ as a dry developing medium. The patterned film then serves as a low-k material compatible with metallization schemes such as the damascene process. This technology would greatly simplify future device manufacture by reducing the number of steps involved in patterning. The CVD process and the use of dry development also offer environmental, safety and health advantages over solvent-based spin-on coating and aqueous development. Positive-tone contrast has been demonstrated in fluorocarbon CVD films and fully-developed images of 0.25-micron have been demonstrated from e-beam exposure. We are presently working to enhance sensitivity and optimize image resolution.