Dry Etch Recipe for Aluminium in Chlorine Based RIE
Recipe
| Gasses: | |
BCl3 | 15 sccm |
Cl2 | 7,5 sccm |
N2 | 50 sccm |
| Pressure | 15 Pa |
| RF Power | 70 W |
| Substrate temperature | ambient |
Etch characteristics
| Etch rate: 17 nm/min |
| Etching is anisotropic |
Selectivity
| Etch rate of AZ 1420: 80 nm/min (selectivity 2) |
| Etch rate of SiO2: 25 nm/min (selectivity 6) |
Remarks
| Considerable loading effect |
| The native AlOx top layer etches very slowly |
| Reproducibility depends strongly on the AlOx top layer |
| The wafer heats up considerably during etching (mask choice!) |
| Anisotropy is due to the inhibiting effect of carbon compounds (mask choice!) |
| Recommended mask is hard baked AZ 1420 or HPR (120 oC) |