Temperature dependence of dielectric constant of nanoparticle composite porous low-k films fabricated by pulse radio frequency discharge with amplitude modulation

Nanoparticle composite porous low-k films are deposited by pulse radio frequency (RF) discharge with the amplitude modulation (AM) of discharge voltage. The deposition rate obtained with AM is 0.65 nm/s, which is sevenfold as high as that obtained without AM, and porosity = 60-63% and dielectric constant k = 1.1-1.4 for the films obtained with AM are nearly equal to those obtained without AM. The deposition of porous low-k films by pulse RF discharge with AM is a promising method for increasing the deposition rate with a less pronounced agglomeration and without variations in the properties of the films. With decreasing substrate temperature from 403 to 368 K, the porosity of the films increases from 3.5 to 60%, leading to a reduction in their dielectric constant from 2.9 to 1.4. Substrate temperature is a key parameter that determines the porosity and dielectric constant of the porous low-k films.