Determination of thermal activation energy of spin-on MSQ used as interlayer dielectric

Device dimension in VLSI circuit constantly shrink with one main objective, i.e. increase in speed. However, there are other parasitic components in the VLSI circuit other than device dimension that can increase the speed of VLSI circuits. The reduction of dielectric constant of interlayer dielectric (ILD) material can improve the speed due to reduction in parasitic capacitance. Therefore, low dielectric constant (k) materials are being introduced. Low-k dielectric material is categorised as material having dielectric constant of less than 3.0. In this research Methylsilsesquioxane (MSQ), which is a type of spin-on glass (SOG), is being used as it offers low fabrication cost. There was reported activation energy for SiO₂ but there is no activation energy information for MSQ. Using the technique of leakage current measurement at different bake temperatures, the activation energy of MSQ degradation due to Aluminium diffusion is approximately determined to be 0.35 eV.