Disclosed herein are techniques for using diblock copolymer (DBCP) films
as etch masks to form small dots or holes in integrated circuit layers.
In an embodiment, the DBCP film is deposited on the circuit layer to be
etched. Then the DCBP film is confined to define an area of interest in
the DCBP film in which hexagonal domains will eventually be formed. Such
confinement can constitute masking and exposing the DCBP film using
photolithographic techniques. Such masking preferably incorporates
knowledge of the domain spacing and/or grain size of the to-be-formed
domains in the area of interest to ensure that a predictable number
and/or orientation of the domains will result in the area of interest,
although this is not strictly necessary in all useful embodiments.
Domains are then formed in the area of interest in the DBCP film which
comprises a hexagonal array of cylindrical domains in a matrix. The film
is then treated (e.g., with osmium or ozone) to render either the domains
or the matrix susceptible to removal, while the other component is then
used as a mask to etch either dots or holes in the underlying circuit
layer.