Ultralow dielectric cross-linked silica aerogel nanocomposite films for interconnect technology

• Published in: Applied materials today 2022-08, Vol.28, p.101536, Article 101536
• Main Authors: Choi, Haryeong, Kim, Taehee, Kim, Taeho, Moon, Sunil, Yoo, SangHyuk, Parale, Vinayak G., Dhavale, Rushikesh P., Kang, Keonwook, Sohn, Hyunchul, Park, Hyung-Ho
• Format: Article
• Language: English
• Subjects: Aerogels; Cross-linked aerogel films; Interlayer dielectric; Spin coating; Ultralow- κ
• ISSN: 2352-9407; 2352-9415
• DOI: 10.1016/j.apmt.2022.101536

•Silica aerogel thin film showed an ultralow dielectric constant of 1.7.•Epoxide based linker enhanced the mechanical property of the silica aerogel films.•Cross-linked aerogel films achieved the robust modulus over 5.1 GPa.•Compatibility to semiconductor process were evaluated to demonstrate applicability. An increase in resistance and capacitance (RC) delay has been a critical issue in reducing integrated circuit scales. The delay is successfully reduced using low dielectric constant (κ) interconnects and porous low-κ materials adopted in real devices. However, an increase in porosity could lower κ values with a dramatic decrease in elastic modulus, which would not sustain the stress during the packaging process. Highly porous cross-linked silica aerogel thin film with an ultralow-κ value of 1.7 applied to nanodevice interconnect technology has been suggested. Cross-linking using an epoxide ring-opening reaction produced a high elastic modulus (> 5.1 GPa), stable enough to sustain the chemical mechanical polishing (CMP) and the plasma dry etching process. The thickness of aerogel films is approximately 700 nm with a hydrophobic surface. Closed-surface pores created by selective solvent evaporation can prevent metal penetration. Our cross-linked aerogel films are the first among the low-dielectric aerogel films validated as interlayer low-dielectric materials and robust candidates for ultralow -κ dielectric materials. [Display omitted]