Low dielectric constant ultrathin polyimide films alternated by poly(amic acid) salt/poly(allylamine hydrochloride)/imogolite through layer by layer deposition

• Published in: Advanced composites and hybrid materials Vol. 6; no. 6
• Main Authors: Yin, Liying, He, Yingqi, Guo, Wenhui, Wang, Shunyu, He, Jianxin, Wang, Tianyu
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.12.2023
• Subjects: Ceramics; Chemistry and Materials Science; Composites; Glass; Materials Engineering; Materials Science; Natural Materials; Polymer Sciences; Polyimide film; Imogolite nanotube; Dielectric constant; Layer by layer
• ISSN: 2522-0128; 2522-0136
• DOI: 10.1007/s42114-023-00795-1

The ultrathin polyimide films with low dielectric constant have been fabricated by static electronic layer by layer self-assembly of poly(amic acid) salt (PAAs)/poly(allylamine hydrochloride) (PAH)/imogolite nanotubes followed by heat-induced imidization. The imogolite nanotubes were introduced to form a nano-porous composite polyimide film, which exhibited a lower dielectric constant of 2.78 compared to 3.25 for pure polyimide film. The assembly film thickness was about 12.2 nm in each cycle multilayer and reduced to 10.7 nm after heat-induced imidization due to the loss of hydrated water from imogolite nanotubes. The multilayer growth was found to be steady and uniform, and the growth relationship of the film was linear. Heating of PAAs/PAH/imogolite film at 250 °C for 2 h completely converted the poly(amic acid) to the corresponding polyimide. Electrostatic deposition of poly(amic acids) and imogolite nanotubes thus provides a convenient way to prepare ultrathin polyimide films with low dielectric constant. Therefore, this porous polyimide/imogolite nanotubes composite film with low dielectric constant has potential applications as interlayer dielectrics in integrated circuit manufacturing. Graphical abstract