Dry Etching of Germanium Using Inductively Coupled Ar/CCl2F2/Cl2 Plasma

In this study, the etch characteristics of Ge are investigated using inductively coupled Ar/CCl2F2/Cl-2 plasmas. The etch rate, surface morphology and subtended angle obtained with different etching conditions are presented. The etch rate of Ge increases from 374 angstrom/min to 520 angstrom/min as the ICP power increases from 400 to 700 W. whereas the etching rate of Ge decreases from 524 angstrom/min to 400 angstrom/min as CCl2F2 flow increases from 40 seem to 80 seem. In addition, the etching rate of Ge decreases from 467 angstrom/min to 400 angstrom/min as the Cl-2 flow increases from 0 seem to 20 seem. As the ICP power increases the subtended angle also increases. According to SEM imagery Ar/CCl2F2/Cl-2 ICP etching leads to the presence of carbon-based material in the form of large particles.