| Sample No. | dSi [nm] (estimated) |
| Si-layer-thickness ratio: dSi/(dSi + |
| 1 | 0.6 | 3.4 | 0.15 |
| 2 | 0.8 | 2.7 | 0.23 |
| 3 | 0.9 | 2.9 | 0.24 |
| 4 | 1.0 | 2.9 | 0.26 |
| 5 | 1.0 | 2.6 | 0.27 |
| 6 | 0.9 | 2.2 | 0.29 |
| 7 | 1.1 | 2.3 | 0.32 |