Conference paper
Wafer bonded CMUT technology utilizing a Poly-Silicon-on-Insulator wafer
Department of Health Technology, Technical University of Denmark1
Center for Fast Ultrasound Imaging, Biomedical Engineering, Department of Health Technology, Technical University of Denmark2
Mems Applied Sensors Group, Biomedical Engineering, Department of Health Technology, Technical University of Denmark3
Biomedical Engineering, Department of Health Technology, Technical University of Denmark4
Optofluidics, Nano and Bio-physical Systems, Department of Health Technology, Technical University of Denmark5
Nano and Bio-physical Systems, Department of Health Technology, Technical University of Denmark6
This paper presents a fabrication process of a Poly-Silicon-On-Insulator (PSOI) wafer that can be used as an alternative to conventional Silicon-On-Insulator (SOI) wafers for fabrication of Capacitative Micromachined Ultrasound Transducers (CMUT). The fabrication of PSOI wafers does, unlike the conventional SOI fabrication, not involve any bonding steps.
A batch of PSOI wafers having a 400 nm BOX layer and a 2.6 µm ± 0.04 µm (1σ) device layer is fabricated and characterized. A surface roughness of 0.47 nm is measured for the PSOI device layer, and successful fusion bonds (direct bonds) are demonstrated between PSOI wafers and oxidized silicon wafers.
A wafer-bonded CMUT using a PSOI wafer is fabricated and electrically characterized, and the expected CMUT performance is observed. Impedance spectra are demonstrated at five different DC biases, the expected spring softening effect is observed when the magnitude of the DC bias is increased.
| Language: | English |
|---|---|
| Publisher: | IEEE |
| Year: | 2019 |
| Pages: | 758-761 |
| Proceedings: | 2019 IEEE International Ultrasonics Symposium |
| ISBN: | 1728145953 , 1728145961 , 172814597X , 172814597x , 9781728145952 , 9781728145969 and 9781728145976 |
| ISSN: | 19485727 |
| Types: | Conference paper |
| DOI: | 10.1109/ULTSYM.2019.8925931 |
| ORCIDs: | Engholm, Mathias , Grass, Rune Sixten , Jensen, Jørgen Arendt and Thomsen, Erik Vilain |
