Abstract
In this paper, the design, fabrication and characterization of PMUTs for medical applications are discussed. Scandium (20% Sc/(Sc + Al)) doped AlN is used as the piezoelectric material. The fabrication process for PMUTs with a patterned piezoelectric layer is developed. Single-cell and linear arrays of PMUT are fabricated and electrical, mechanical and acoustic characterization is carried out. The piezo-patterning improved the performance of PMUTs. The fabricated PMUT showed excellent chip-wafer level uniformity and yield. At resonance (5.7 MHz), the ScAlN PMUT array showed transmit sensitivity of 13 kPa/V and receive sensitivity of 1.1 V/MPa. The good transmit-receive properties and the ability to operate without bias voltage make the ScAlN PMUTs best for voltage-limited medical applications. 2023-0131
| Original language | English |
|---|---|
| Pages (from-to) | 505-512 |
| Number of pages | 8 |
| Journal | Journal of Microelectromechanical Systems |
| Volume | 32 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - Oct 2023 |
| MoE publication type | A1 Journal article-refereed |
Keywords
- Aluminum nitride
- cavity silicon on insulator (CSOI)
- Electrodes
- Fabrication
- III-V semiconductor materials
- Medical services
- medical ultrasound
- PMUT
- ScAlN
- Sensitivity
- Stress