A method for filling a gap feature on a substrate surface is disclosed. The method may include: providing a substrate comprising a non-planar surface including one or more gap features; depositing a metal oxide film over a surface of the one or more gap features by a cyclical deposition process; contacting the metal oxide with an organic ligand vapor; and converting at least a portion of the metal oxide film to a porous material thereby filling the one or more gap features. Semiconductor structures including a metal-organic framework material formed by the methods of the disclosure are also disclosed.