Preparation And Properties Of Polyimide Films With Low Dielectric Permittivity

Low dielectric permittivity materials were explored in order to reduce the resistance capacitance time (RC) delay, cross-talks and power consumption caused by the increasing device densities in ultra-large-scale integrated (ULSI) circuits. Polymer-based low-k films have been proved to be promising for use in the microelectronics industry. The introduction of pores into a fluorinated polyimide results in further reduction of the dielectric permittivity.In the present work, we studied the preparation and properties of nanoporous polyimide films with low dielectric permittivity. SiO2/PI nanocomposite films based on ODA-PMDA and 3FEDAM- 6FDA were successfully synthesized by a wet phase inversion process. Then removal of the silica cores of the nano-composite films by HF etching gives rise to the nanoporous of polyimide films. The structure of monomers can be characterized by 1H NMR and FT-IR spectroscopy. TEM images are used to display the porous structure of polyimide films. The relationships between the structure of the films and the properties, including the dielectric permittivity, the heat resistance, the contact angles and the mechanical strength, were researched.The fluorinated polyimide films were successfully synthesized with nanoporous of 40nm size. The dielectric permittivity of porous F-PI films was decreased to 2.45 with good mechanical properties and thermal stability. So this type of novel polyimide films can be used as alternative dielectric layers in the microelectronic industry.