Selective area etching of InP with CBr4 in MOVPE

We report on the in situ selective area etching (SAE) of InP using carbon tetrabromide (CBr4) in a metal organic vapor phase (MOVPE) reactor at different pressures and temperatures. Etch rate dependence on growth temperature from 550 to 700 °C and growth pressure from 50 to 90 Torr was evaluated. Etch rates were determined by in situ optical reflectance measurements for planar wafers. Selective area etch rate was evaluated by Dektak and atomic force microscopy (AFM) for enhanced etch rates within oxide pad areas. It is shown that pre-etching InP with CBr4 reduces the effect of excessive edge growth enhancement in selective area growth (SAG). By improving wafer planarity of SAG regrowth, CBr4 pre-etch is beneficial to the fabrication of integrated optoelectronic devices.