Fluorinated polymides for interlayer dielectric applications: Tailoring of properties via copolymerization

Conference · Tue Oct 01 04:00:00 UTC 1996

OSTI ID:370848

Auman, B C ^[1]; McKerrow, A J; Ho, P S ^[2]

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1. Du Pont Electronic Materials, Wilmington, DE (United States)
2. Univ. of Texas, Austin, TX (United States); and others

Over the past several years DuPont has been exploring new, rod-like fluorinated polyimides for interlayer dielectric (ILD) applications. It has been shown that copolymerization is a versatile method for tailoring properties of these rigid polyimides. Initial product offerings from DuPont showed an excellent balance of properties for ILD applications. These materials, however, due to their highly rod-like structure and very low in-plane coefficient of thermal expansion (CTE), actually yielded negative thermal stresses on silicon at the 1 {mu}m thicknesses typical of interlayer dielectrics. More flexible materials with higher CTE typically yield positive stress values which can be undesirably quite high. The dielectric constant of these highly rod-like fluorinated polyimides was also somewhat anisotropic, again due to the rod-like nature and resulting high in-plane orientation of these polyimides. Since a thermal stress on silicon near zero and a more isotropic dielectric constant are likely the most desirable states for an ILD, the highly rod-like polyimide was further optimized by incorporation of a more flexible fluorinated comonomer, 6FDA, at various levels to increase CTE and balance dielectric constant. The various properties of this series of fluorinated polyimides were investigated. The results have shown that it is indeed possible to obtain near zero stress on silicon while attaining more isotropic dielectric constant via structure optimization.

• OSTI ID: 370848
• Report Number(s): CONF-960376--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COPOLYMERIZATION
DIELECTRIC PROPERTIES
IMIDES
ORGANIC FLUORINE COMPOUNDS
ORGANIC POLYMERS
THERMAL EXPANSION
THERMAL STRESSES