Nonselective vertical etching of GaAs and AlGaAs/GaAs in high pressure capacitively coupled BCl 3/N 2 plasmas

Abstract

We studied nonselective, vertical dry etching of GaAs and AlGaAs/GaAs structure in high pressure capacitively coupled BCl 3/N 2 plasmas. The operating pressure was fixed at 150 m Torr. We found that there was an optimized process condition for nonselective and vertical etching of GaAs and AlGaAs/GaAs at the relatively high pressure. It was noted that there was a range of % N 2 (i.e. 20–40%) where nonselective etching of GaAs over AlGaAs could be achieved in the BCl 3/N 2 mixed plasma. We also found that dry etching of GaAs and AlGaAs/GaAs structure provided quite vertical and smooth surface when % N 2 was in the range of 0–20% in the BCl 3/N 2 plasma. The maximum etch rates for GaAs (0.41 μm/min) and AlGaAs/GaAs structure (0.42 μm/min) were obtained with 20–30% N 2 composition in the plasma.