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/Cl₂ plasmas. The etch rate, surface morphology and subtended angle obtained with different etching conditions are presented. The etch rate of Ge increases from 374 Å/min to 520 Å/min as the ICP power increases from 400 to 700 W, whereas the etching rate of Ge decreases from 524 Å/min to 400 Å/min as CCl₂F₂ flow increases from 40 sccm to 80 sccm. In addition, the etching rate of Ge decreases from 467 Å/min to 400 Å/min as the Cl₂ flow increases from 0 sccm to 20 sccm. As the ICP power increases the subtended angle also increases. According to SEM imagery Ar/CCl₂F₂/Cl₂ ICP etching leads to the presence of carbon-based material in the form of large particles.