Wafer Lapping and Polishing Raw wafers are lapped and polished to a
mirror-like finish. For some applications, a thin layer of
silicon with different electrical characteristics than the
underlying wafer is deposited on the wafer's surface. Wafers
are then cleaned and dried.
Oxidation After cleaning, oxygen or water vapour
reacts chemically with the silicon wafer surface at high
temperature to form thin, uniform layers of silicon dioxide
in a furnace.
Align and Expose: At this stage, circuit patterns are
imaged from a reticle or mask onto the coated wafer in a scanner.
Chemical Vapor Deposition: Insulating or conducting
layers are deposited on the wafer surface via a chemical
reaction or plasma discharge to obtain a conformal coating.
Coating: The photolithography process begins
by spreading photosensitive material, called photoresist,
evenly over the water surface. The material is baked
at a low temperature to remove the solvent.
