Dry etching of InGaP in magnetron enhanced BCl₃ plasmas

Magnetron enhanced reactive ion etching of In_0.5Ga_0.5P was investigated in BCl₃ plasmas. Etch rates were determined as a function of cathode power (0.2–0.5 W/cm²), BCl₃ flow rate (3–12 sccm), and pressure (2–10 mTorr), with rates as high as 0.35 μm/min achieved. The addition of N₂, O₂, and Ar to BCl₃ was ineffective in producing an etch rate increase. Changes in sheet resistance and photoluminescence of n- and p-type InGaP exposed to BCl₃ plasmas were also investigated as a function of power, pressure, and etch duration. The n-type material was more susceptible to etch-induced damage than p-type material, suggesting that electron traps are produced by ion bombardment. Scanning electron micrographs showed etched surfaces to be smooth, with vertical sidewalls free of undercut.