Electron cyclotron resonance (ECR) plasma etching with additional rf-b
iasing produces etch rates greater than or equal to 2,500 A/min for In
GaP and AlInP in CH4/H-2/Ar. These rates are an order of magnitude or
much higher than for reactive ion etching conditions (RIE) carried out
in the same reactor. N-2 addition to CH4/H-2/Ar can enhance the InGaP
etch rates at low flow rates, while at higher concentrations it provi
des an etch-stop reaction. The InGaP and AlInP etched under ECR condit
ions have somewhat rougher morphologies and different stoichiometries
up to similar to 200 Angstrom from the surface relative to the RIE sam
ples.