Characterization of Germanium dry etching using inductively coupled BCl₃ plasma

This study investigates the etch rates and the etched surface for Ge as a function of variations in the BCl₃ flow rate, inductively coupled plasma (ICP) power and work pressure. It was found that the peak etch rate is at 40 sccm of a BCl₃ flow rate. The etch rate of Ge decreases from 2370 to 1780 Å/min as the BCl₃ flow rate increases from 40 to 80 sccm. The etch rate of Ge decreases from 2835 to 2094 Å/min as ICP power increases from 200 to 500 W, whereas the etching rate of Ge increases from 2370 to 2900 Å/min as work pressure increases from 10 to 50 mTorr. The etched surface has a very smooth surface appearance at parameters of a BCl₃ flow rate of 40 sccm, 400 W of ICP power, and 10 of mTorr work pressure.