A method for marking a semiconductor wafer 302 includes the steps of:
providing a reticle 300 including liquid crystal pixels; positioning the
semiconductor wafer in proximity to the reticle; directing radiation
through a first plurality of the pixels onto a first location on the
wafer; changing the relative positions of the semiconductor wafer and the
reticle; and directing radiation through a second plurality of the pixels
onto a second location on the wafer. The first plurality of pixels can be
used to form a first mark and the second plurality of pixels can be used
to form a second mark, wherein the second mark is different from the
first mark. The marks can be made of a pattern of dots in order to save
space. The pixels can be selected to form certain marks by using a
computer 304 to turn on or off a transistor that may be associated with
each pixel. Also described is a system for marking a semiconductor wafer.
The system includes a wafer mount 301; a radiation source 306 in
proximity to the wafer mount; a reticle 300 which includes liquid crystal
pixels and that is positionable between the radiation source and the
wafer mount; and a mechanism 303 for changing the relative positions of
the reticle and the wafer mount. The radiation source can be non-coherent
far-ultraviolet, near-ultraviolet, or visible sources, or a laser.