Table 1.
Design parameters of structural dimensions and related material properties (σ: stress, E: Young’s modulus, ν: Poisson’s ratio)
| Parameter | Size [µm] | Relevant parameters |
|---|---|---|
| Sensor Chip | ||
| Width | 870 | |
| Length | 3200 | |
| Substrate thickness | 500 | |
| Membrane | σ 26 MPa | |
| Radius | 250 | |
| Electroplated Au thickness | 2.5 to 6.5a | E 78 GPa, ν 0.44 |
| Ti (adhesion layer) thickness | 0.020 | E 116 GPa, ν 0.32 |
| Parylene thickness | 4.6 | E 2.76 GPa, ν 0.40 |
| Sensor Gap (before Sealing) | 2.8 | |
| Fixed Au Electrode | ||
| Si3N4 thickness | 0.275 | ε 9.7b |
| Au thickness | 0.11 | |
| Substrate SiO2 thickness | 1.5 | |
| Au Switch Leads | ||
| Width | 4 | |
| Spacing | 4 | |
| Offset from center | 4 | |
| Fixed Switch Capacitors | C ~3.12 pF/Switch | |
| Length | 50 | |
| Width | 200 | |
| Si3N4 thickness | 0.275 | ε 9.7b |
| Release/Seal Channels | 4 Channels/Cavity | |
| Overall length | 178 | |
| Overall width | 420 | |
| Channel entrance width | 10 | |
aThe fabricated sensor had a 2.85-µm thickness.
bThe constant was experimentally measured with the capacitance and known area of characterization structures.