Specific Process Knowledge/Etch/Etching of TOPAS
Etching of TOPAS
TOPAS is etched by an oxygen plasma in the ASE. Masking of TOPAS was achieved by photo resist or a hard mask of aluminum or silicon. Photo resist is the preferred masking material, since hard masks tends to introduce local masking due to redeposition. TOPAS can be etched at rates up to 500 nm/min, with excellent uniformity over the wafer.
| Parameter | TOPAS etch |
|---|---|
| O2 (sccm) | 99 |
| CO2 (sccm) | 0 |
| Pressure (mTorr) | 40 |
| Coil power (W) | 720 |
| Platen power (W) | 60 |
| Temperature (oC) | 20 |
| Etch rate (nm/min) | ~500 |