Effects of plasma power and deposition pressure on the properties of the low dielectric constant plasma polymerized cyclohexane thin films deposited by plasma enhanced chemical vapor deposition

Abstract

Effects of plasma power and deposition pressure on the properties of low dielectric constant plasma polymerized cyclohexane (PPCHex) thin films deposited by plasma enhanced chemical vapor deposition were investigated. As plasma power increased, the relative dielectric constant (k) value increased, while the C-H bonding concentration decreased. Unlike the power, as deposition pressure increased, k value decreased and the C-H bonding concentration increased. Increase of plasma power could be considered to be quite similar to decrease of deposition pressure. The PPCHex thin films with higher k values had smaller intensities of C-H bonding concentrations and higher thermal stability. Copper diffusion into the PPCHex thin films was also investigated by current-voltage measurement and transmission electron microsopy. PPCHex thin films were resistant to Cu diffusion up to 400°C, while there was a notable amount of Cu diffused into the PPCHex thin films after 450°C annealing.