High Quality, Low-K, Thermally Conductive COF Thin Films

NU 2020-222

INVENTORS
Austin M. Evans
William R. Dichtel*
Mark C. Hersam*
Vinod K. Sangwan
Ioannina Castano
Patrick E. Hopkins (UVA)*
Ashutosh Giri

SHORT DESCRIPTION
A method for producing high quality, low-k, thermally conductive 2D COF thin films for use as dielectric materials

BACKGROUND
As electronic device components continue to decrease in size, insulating dielectric layers become thinner and existing materials become unsuitable. High-k dielectric materials experience excessive charge buildup, which can lead to crosstalk and signal propagation delay when layers become too thin. Low-k dielectric materials can overcome these issues; however, they are typically thermally insulating, which is troublesome from a heat dissipation standpoint. New low-k, thermally conductive materials are necessary to avoid electrical issues associated with high-k materials and allow adequate heat dissipation. This may facilitate the development of smaller electronic device components.

ABSTRACT
2D COFs are porous polymer frameworks that have a wide variety of applications. Thin films of 2D boronate-ester linked COFs are ultra-low-k and thermally conductive, two properties that are ideal for dielectric layers in small electronic device components. However, current methods of producing these 2D COFs (direct growth, exfoliation, and interfacial polymerization) are not suitable for wafer-scale production of high-quality thin films necessary for use in electronic devices. This technology describes a new method of producing high-quality COF thin-films directly onto substrates of interest using direct polymerization of starting material colloids. The resulting COF thin-films have excellent crystallinity, uniformity, and control of thickness. These materials, once deposited on substrates, were shown to be thermally conductive and ultra-low k.

APPLICATIONS