| abstract |
PROBLEM TO BE SOLVED: To provide a porous silica thin film having a low relative dielectric constant of a porous silica thin film and having sufficient mechanical strength to withstand a CMP step in a copper wiring step of a semiconductor element. SOLUTION: The crosslinking ratio of the porous silica thin film is 70% or more, and the scattering angle (2θ) in X-ray scattering measurement is 0.5 to 0.5%. At least one scattering peak exists between 3 °, And a porous silica thin film having a surface density of silanol groups of 2% or less. |