A design approach for ultra-low-k dielectric organosiloxane polymers

Capacitance reduction is crucial for advanced interconnect scaling. Decreasing dielectric constant of inter layer dielectric (ILD) and inter metal dielectric (IMD) contributes significantly to the decrease of capacitance. Spin-on organosiloxane polymers have many advantages as ILD and IMD materials, including high thermal stability, easy processing, and dielectric constant (k) lower than 3. For further k reduction, introduction of porosity is the most common strategy to achieve k< 2.7. However, highly porous materials can suffer from e.g. poor mechanical properties, resulting in several integration challenges. We have demonstrated a material design approach for low-k organosiloxane dielectric polymers, enabling ultra-low-k (<2.5) spin-on thin films without introducing porosity to material.