Ultralow k SiO/sub 2/ thin films with nano-voids by gas-evaporation technique

Abstract

We have developed the gas evaporation technique to deposit ultralow-k (as low as 1.7) SiO/sub 2/ thin films with nanometer-size voids. In the technique silicon (Si) in a boat was evaporated in argon gas containing a small amount of oxygen. Although the film contains many nanometer-size voids, it is tolerant of moisture and does not show a change in the dielectric constant or the resistance with time. The SiO/sub 2/ film deposited by the gas evaporation technique is a good candidate for a low-k dielectric in the future Si VLSI.