Application of charge-based capacitance measurement technique in characterization of hydrogen silsesquioxane

The charge-based capacitance measurement technique was employed to measure femtofarad-level interconnect capacitance, to evaluate the dielectric constant of hydrogen silsesquioxane (HSQ) intermetal dielectric, and to study dielectric anisotropy of HSQ. It is demonstrated that high temperature processes during hack end integration will affect the dielectric property of HSQ and therefore an alternative thermal curing condition is required. An over 25% reduction in intracapacitance for 0.32 μm spaced metal lines has been achieved. The underlying dielectric liner has insignificant impact on parasitic interconnect capacitance. HSQ exhibits anisotropic dielectric behavior which is desirable in minimizing both resistance capacitance delay and cross talk.