Preparation And Properties Of Polyimide/Mesoporous Silica Sieve Composite Films With Low Dielectric Constant

Low dielectric constant 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 dielectric composite films heve been proved to be promising for use in the microelectronics industry. The MCM-41 with the ultra low dielectric constant was mixed into polymers to obtain the low-k composite films.In this work, preparation and properties of polyimide/mesoporous sieve (PI/MCM-41) composite films were studied. The mesoporous sieve MCM-41 was synthesized by the sol-gel method, and low-k PI/MCM-41 composite films with different loading of MCM-41 particles were prepared using the methods of in-situ polymerization and ball-milling, respectively. TEM, SEM, thermal constants analyzer, impedance analyzer were used to characterize the microstructures and measure the thermal and dielectric properties of the achieved PI/MCM-41 composite films. The results showed that MCM-41 particles were dispersed well in PI matrix and the dielectric constant of PI/MCM-41 composite films was decreased to 2.58. Meanwhile, the volume resistivity and breakdown strength were increased to 3.139×10¹⁶Ω.m and 255.45 MVm^-1, respectively. It was obvious that the dielectric properties of PI/MCM-41 composite films by ball-milling are better than those prepared by in-situ dispersion polymerization. Therefore, this kind of PI/MCM-41 composite films has potential and broad applications in microelectronic industry.