ABSTRACT
This chapter examines the advances made in patterning group-III nitrides. The group-III nitride materials are chemically inert and resist etching in common compound semiconductor material wet chemical etchants at room temperature. Very slow etching of GaN has been reported in hot alkalis or electrolitically in NaOH. The high rates and anisotropic profiles often achieved with RIE are attributed to the acceleration of energetic ions from the plasma to the wafer. However, this energetic ion bombardment of the surface can damage the sample and degrade both electrical and optical device performance. Similar to the trends observed for the GaN and AIN films, the etch rates increased as the pressure was increased from 1 to 2 mTorr suggesting a reactant limited regime at 1 mTorr. As the pressure was increased above 2 mTorr, the etch rates decreased due either to lower plasma density or to increased polymer deposition at higher pressures.
