PHOTOELECTROCHEMICAL ETCHING OF BLAZED ECHELLE GRATINGS IN N-GAAS

It is the purpose of this communication to report the photoelectrochemical fabrication of blazed, deep gratings with crystallographic control of the glaze angle. It is found that in order to produce blazed Echelle gratings, it is necessary to cut the GaAs crystal at an angle off the (100) plane toward the (011) plane. Orienting the photoresist lines in the [011¯] direction should then give rise to structures with the interior angles governed by the preferred Ga-rich surfaces. One advantage of photoelectrochemical etching for producing these structures is that the process can be followed coulometrically.