Monolithic CMUT-on-CMOS integration for intravascular ultrasound applications
Yükleniyor...
Dosyalar
Tarih
2011-12
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
IEEE-INST Electrical Electronics Engineers Inc
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
One of the most important promises of capacitive micromachined ultrasonic transducer (CMUT) technology is integration with electronics. This approach is required to minimize the parasitic capacitances in the receive mode, especially in catheter-based volumetric imaging arrays, for which the elements must be small. Furthermore, optimization of the available silicon area and minimized number of connections occurs when the CMUTs are fabricated directly above the associated electronics. Here, we describe successful fabrication and performance evaluation of CMUT arrays for intravascular imaging on custom-designed CMOS receiver electronics from a commercial IC foundry. The CMUT-on-CMOS process starts with surface isolation and mechanical planarization of the CMOS electronics to reduce topography. The rest of the CMUT fabrication is achieved by modifying a low-temperature micromachining process through the addition of a single mask and developing a dry etching step to produce sloped sidewalls for simple and reliable CMUT-to-CMOS interconnection. This CMUT-to-CMOS interconnect method reduced the parasitic capacitance by a factor of 200 when compared with a standard wire-bonding method. Characterization experiments indicate that the CMUT-on-CMOS elements are uniform in frequency response and are similar to CMUTs simultaneously fabricated on standard silicon wafers without electronics integration. Experiments on a 1.6-mm-diameter dual-ring CMUT array with a center frequency of 15 MHz show that both the CMUTs and the integrated CMOS electronics are fully functional. The SNR measurements indicate that the performance is adequate for imaging chronic total occlusions located 1 cm from the CMUT array.
Açıklama
work was supported by the National Institutes of Health under the grants HL082811 and EB010070
Anahtar Kelimeler
Chronic total occlusions, Front-end electronics, Arrays, Transducers, Future, Fabrication, Metals, Surface topography, Surface treatment, Wires, Electronics, Equipment Design, Equipment failure analysis, Image enhancement, Micro-electrical-mechanical systems, Miniaturization, Reproducibility of results, Semiconductors, Sensitivity and specificity, Systems integration
Kaynak
IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control
WoS Q Değeri
Q1
Scopus Q Değeri
Q1
Cilt
58
Sayı
12
Künye
Zahorian, J., Hochman, M., Xu, T., Satir, S., Gurun, G., Karaman, M., & Degertekin, F. L. (2011). Monolithic CMUT-on-CMOS integration for intravascular ultrasound applications. IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 58(12), 2659-2667. doi:10.1109/TUFFC.2011.2128
