A method for anisotropic plasma etching of organic-containing insulating
layers is disclosed. According to this method at least one opening is
created in an organic-containing insulating layer formed on a substrate.
These openings are created substantially without depositing etch residues
by plasma etching said insulating layer in a reaction chamber containing a
gaseous mixture which is composed such that the plasma etching is highly
anisotropic. Examples of such gaseous mixtures are a gaseous mixture
comprising a fluorine-containing gas and an inert gas, or a gaseous
mixture comprising an oxygen-containing gas and an inert gas, or a gaseous
mixture comprising HBr and an additive. The plasma etching of the
organic-containing insulating layer can be performed using a patterned
bilayer as an etch mask, said bilayer comprising a hard mask layer, being
formed on said organic-containing insulating layer, and a resist layer
being formed on said hard mask layer. A method is disclosed for forming a
layer, protecting exposed surfaces of low-k dielectrics. More particularly
the method comprises the steps of sealing exposed surfaces of a,
preferably porous, low-k dielectric, by forming a protective layer on
exposed surfaces during or after the step of patterning openings in the
porous dielectric layers. Preferably this protective layer is formed by a
N2/O2 plasma treatment of the exposed surfaces.
