The present invention includes a residue-free overlay target, as well as a method
of forming a residue-residue free overlay target. The residue-free overlay target
of the present invention is defined by trenches or pads including a series of raised
lines. The raised lines included in the overlay target of the present invention
substantially eliminate any surface topography, such as depressions, at the top
surface of overlying material layers, and, thereby, prevent accumulation of process
residue which may obscure the overlay target and inhibit further processing. The
method of the present invention may be accomplished and modified using process
technology known in the semiconductor fabrication art and includes providing a
semiconductor substrate, depositing a resist layer, patterning the resist, and
executing a wet or dry etch to create at least one overlay target according to
the present invention.
