Inductively coupled plasma-induced etch damage of GaN p-n junctions

Plasma-induced etch damage can degrade the electrical and optical performance of III–V nitride electronic and photonic devices. We have investigated the etch-induced damage of an inductively coupled plasma (ICP) etch system on the electrical performance of mesa-isolated GaN pn-junction diodes. GaN positive-insulating-negative mesa diodes were formed by Cl2/BCl3/Ar ICP etching under different plasma conditions. The reverse leakage current in the mesa diodes showed a strong relationship to chamber pressure, ion energy, and plasma flux. Plasma induced damage was minimized at moderate flux conditions (⩽500 W), pressures ⩾2 mTorr, and at ion energies below approximately −275 V.