Laser Chemical Etching of Semiconductors Carol I. H. Ashby Many
of today's important technologies require selective removal of
small regions of a thin film to produce a particular pattern.
Laser-driven chemical reactions have been extensively studied as
alternatives to current ion-beam-based etching processes, such
as ion-beam milling and reactive ion etching (RIE). The
attraction of photon-based processes lies in their ability to
selectively etch very small features with little or no substrate
damage using a range of reactants, temperatures, and pressures.
There are three general reaction classes: thermal chemical
reactions, photochemical reactant generation, and carrier-driven
reactions. The most appropriate type to use depends on the
specific application. Although most research has employed
lasers, one should always bear in mind that there is nothing
magic about using a laser except when extremely monochromatic or
highly coherent light is required. For many applications, high-
intensity lamps might be a bet