in cooperation with LS Polymeric Materials of BTU Cottbus – Senftenberg
Miniaturization of microelectronic components requires the development of novel insulation coatings with low dielectricity constants of k< 4 (low-k-dielektrika), while so-called ultra-low-k materials with k < 2.4 are aimed for. In principle there are two ways to lower the dielectricity constant:
- Lowering of the polarizability (dipole strength) through use of substances with less polar bonds such as C-C, C-H, Si-F and Si-C bonds.
- Lowering of the density (dipole density) via creation of free volume and/or generation of locally confined pores.
The aim of this project was the development of novel low-k polymer materials with larger free volume on the basis of polycyanurate and perfluorocyclobutane (PFCB) polymers. These novel low-k polymers are produced without generation of pores by inclusion of bulky monofunctional structural elements to increase free volume. This avoids the described problems of integration for porous materials during processing.
The dielectricity constant could be lowered to presently k = 2.51 for a polycyanurate copolymer with a large percentage of monofunctional components. The good mechanical and thermal properties of polycyanurates were retained. The current industrial requirements for low-k materials with with respect to leakage current density (< 10-9 A/cm) and breakdown field strength EBD (> 3 MV/cm) were met. In addition, an adapted processing sequence was developed and applied successfully to the basic polymer. These results are a very promising basis for the successful integration into a copper metallization.
This project (01.07.2002 - 31.12.2006) was funded by the DFG (BA 1168/10 – 1) and carried out in cooperation with the Chair in Microtechnology of the Faculty for Electrotechnology and Information Technology at TU Chemnitz.
K. Schulze, U. Schuldt, O. Kahle, S. E. Schulz, M. Uhlig, C. Uhlig, C. Dreyer, M. Bauer, T. Gessner: Novel Low-k Polycyanurates for Integrated Circuit (IC) Metallization, Microelectronics Engineering 82 (3-4), p. 356-361 (2005)
C. Dreyer, J. Schneider, N. Keil, C. Zawadzki, H. H. Yao, U. Schuldt, K. Schulze, O. Kahle, S. E. Schulz, M. Uhlig, C. Uhlig, C. Boeffel, T. Gessener, M. Bauer: Material Development for Integrated Optics, Microelectronics and Display-Technology - Selected Examples, MicroSystem Technologies 2005, H. Reichl (ed.), ISBN 3-7723-7040-3, p. 455-462 (2005)
C. Dreyer, M. Bauer, J. Schneider, C. Boeffel, O. Kahle, C. Uhlig, U. Schuldt, N. Keil, H. H. Yao, C. Zawadzki: Fluorinated Polymers for High-Performance Applications, Science for Innovation, Brüssel (B), 04./05.10.2005
K. Schulze, U. Schuldt, O. Kahle, S. E. Schulz, M. Uhlig, C. Uhlig, C. Dreyer, M. Bauer, T. Gessner: Polycyanurates – A Low-k Material Approach, European Congress on Advanced Materials and Processes EUROMAT, Prag (CZ), 5.-8.9.2005