低k介质电特性.ppt

Low-k Dielectrics: Materials and Process Technology Rebeca C. Diaz EE 518, Penn State Instructor: Dr. J. Ruzyllo April 13, 2006 Outline Motivation for low-k dielectrics Required properties of low-k dielectrics Proposed materials Most promising materials CVD vs. Spin-on techniques Conclusion Why Low-k Dielectrics? Reduce RC constant without reducing size R metal interconnect minimized with Cu C dielectric need low-k Why Low-k Dielectrics?2 Required Properties of Low-k Dielectrics2 Proposed Materials2,3 Inorganic/organic Hybrid: MSQ (k = 2.0)2 HOSP (Honeywell) “Carbon-doped oxide” High thermal stability High resistance to cracks Reactant with stripping chemicals Organic: PAE (k = 2.6)2 FLARE (Honeywell) and VELOX (Schumacher) High thermal stability Low moisture absorption Good adhesion with metals and SiO2 Anisotropic but solved by increasing k to 2.8 Organic: Parylene4 Parylene-N (k = 2.7) Mechanically stable High thermal stability Poor adhesion with Cu Parylene-F (k = 2.4) Same properties as Parylene-N Poor adhesion can lead to corrosion Organic: B-staged polymers (k = 2.6)2 CYCLOTENE (Dow Chemical) Fluorine based Good temperature stability Low metal adhesion Moisture absorption Currently used in GaAs interlayer dielectric SiLK (Dow Chemical) Phosphorous based High temperature stability Good metal adhesion Low mechanical stability Organic: PTFE (k = 1.9)2 SPEEDFILM No moisture absorption Temperature resistant Good adhesion with metals Good mechanical stability Compatible with etching chemistries Porous Organics and Inorganics Add closed cells of air to materials that show promising characteristics Dielectric constants below 2.0 Disadvantages of Porous Materials2 Weakens mechanical properties Lower thermal conductivity Narrow pore distribution to ensure dielectric constant is homogeneous and isotropic Pores need to be closed cells to prevent crack propagation and moisture absorption Need to add silica to seal surface pores Air G