Effects of environment on modulus of low-k porous films used in back end of line

Reliability is an important requirement for newly developed porous low-k interlayer dielectric (ILD) materials that are being introduced into the back-end-of -line (BEOL). Dependence of Young's moduli, as measured by nanoindentation technique, on the environmental factors, such as high relative humidity, water immersion and thermal recovery is presented along with FT-IR spectra for films with different k values. The effect of the moduli changes on cracking behavior is also discussed. © 2007 Materials Research Society.