Dry Etch Recipe of Siliconoxide in Fluorine Based RIE
Recipe
| Gasses: | |
CHF3 | 50 sccm |
O2 | 2.5 sccm |
| Pressure | 0.8 Pa (as low as possible) |
| RF Power | 50 W |
| Bias potential | -350 V |
Etch characteristics
| Etch rate: 45 nm/min |
| Etching is anisotropic |
Selectivity
| Etch rate of AZ 1420: 10 nm/min (selectivity: 1) |
| Etch rate of Si: 10 nm/min (selectivity: 1) |
Remarks
| Etch rate is somewhat aspect ratio dependent |
| The wafer heats up considerably during etching (Mask choice) |
| Wafer uniformity: 10 % |
| Reproducibility: 15% |
| Etch rate is almost proportional to RF power |
| PMMA inhibits etching at high pressure |
| Recommended mask is hard baked AZ 1420 |