Dry Etch Recipe for Ge in Chlorine Based RIE
Recipe
| Gasses: | |
BCl3 | 15.0 sccm |
Cl2 | 15.0 sccm |
He | 17.5 sccm |
| Pressure | 2.00 Pa |
| RF Power | 65 W |
| Substrate temperature | 20 °C |
Etch characteristics
| Etch rate: 195 nm/min |
| Etching is anisotropic |
Selectivity
| Etch rate of AZ 1420: 75 nm/min (selectivity 2.5) |
Remarks
| Considerable loading effect |
| Reproducibility: 10 % |
| Almost no aspect ratio dependence |
| The wafer heats up considerably during etching (mask choice!) |
| Recommended mask is hard baked AZ 1420 or HPR (120 0C) |
| This process is also used for three layer mask processing (descumming of PMMA is necessary before etching the germanium |