UCLA

The continuous scaling of Silicon Complementary Metal-Oxide-Semiconductor (Si CMOS) technology has driven exponential improvements in computing performance over the past several decades. However, as transistor scaling approaches its physical limits, packaging technology has emerged as a critical enabler of continued system-level performance improvements. As one contribution to advanced packaging, University of California, Los Angeles (UCLA) Center for Heterogeneous Integration and Performance Scaling (CHIPS) demonstrated the successful fabrication of a hybrid dielectric substrate by integrating an inorganic dielectric layer on top of an organic dielectric, achieving 10 micrometers (μm) die-to-die bonding pitch. However, this approach relied on conventional organic build-up films, such as Ajinomoto Build-Up Films (ABF), which required lamination and post-lamination thinning to achieve thinner dielectric layers—steps that introduce complexity and process limitations. To address these challenges of conventional laminating process, this thesis investigates a novel spin-coatable dielectric material, Ajinomoto VGL510, as an alternative to conventional dry film ABF in advanced packaging applications.A spin-coating process was developed to achieve precise dielectric thickness control by tuning spin speed and viscosity, enabling film thicknesses below 5 micrometers (μm) without the need for mechanical grinding. This process offers flexibility of choosing different dielectric thickness which helps in impedance matching to improve signal integrity. Furthermore, a dry etching process of the material was established by employing a metal hard mask with vertical sidewall profiles and high anisotropy, thereby supporting fine-pitch via formation. To evaluate the electrical characteristics, test structures were designed and verified by simulation studies. Mechanical reliability was also assessed through adhesion tests to confirm compatibility with advanced packaging requirements. Therefore, these results demonstrate the feasibility of achieving fine pitch patterns on organic dielectrics by utilizing spin-coatable VGL510.