Plasma treatments of molecularly templated nanoporous silica films

Abstract

Oxygen plasma has been successfully utilized to remove the organic template in molecularly templated nanoporous silica films. The resulting nanoporous silica film has a high porosity and a surface roughness of less than 10 Å. The hydrophilic film can be modified to be hydrophobic by reacting with hexamethyldisilazane (HMDS). Reductive plasmas, such as hydrogen and ammonia plasmas, have been applied to reduce the leakage current of the nanoporous silica film without deteriorating the dielectric properties. The dielectric constant of the silica film can be reduced to 1.7 after an HMDS/H2 plasma/HMDS treatment. The leakage current of the plasma-treated silica film can reach below 1 × 10-7 A/cm2 at an electric field of 2 MV/cm. This report shows the feasibility of integration of plasma processes into preparation of molecularly templated nanoporous silica films for ULSI applications.