As the semiconductor nano-electronics industry progresses toward incorporating increasingly lower dielectric constant
materials as the inter layer dielectric (ILD) in Cu interconnect structures, thermo-mechanical reliability is becoming an
increasing concern due to the inherent fragility of these materials. Therefore, the need for metrologies to assess the
mechanical properties and elastic constants of low-k dielectric materials is great. Unfortunately, traditional techniques
such as nano-indentation are being increasingly challenged as target low-k ILD thicknesses decrease below 100 nm for
sub 16 nm technologies. In this light, we demonstrate the applicability of two new techniques, Brillouin Light Scattering and Contact Resonance Atomic Force Microscopy, for the determination of Young’s modulus for low-k dielectric thin films. We show that these techniques yield values that are in agreement with standard nano-indentation measurements and are capable at film thickness on the order of 100 nm or less.
Plasma-induced damage to low-k dielectric materials can be quantified by separation of the effects of charged-particle
bombardment, photon bombardment, and gas-radical flux. For ion and photon bombardment, the spatial location and
extent of the damage can be determined. Damage effects from radical flux will be shown to be small. Both SiCOH and
photo-programmable low-k (PPLK) dielectrics will be discussed.