Piezoelectric aluminum nitride thin films for ultrasonic transducers

Laurie Valbin; Laure Sevely

doi:10.1117/12.443023

1 October 2001 Piezoelectric aluminum nitride thin films for ultrasonic transducers

Laurie Valbin, Laure Sevely

Proceedings Volume 4559, MEMS Components and Applications for Industry, Automobiles, Aerospace, and Communication; (2001) https://doi.org/10.1117/12.443023
Event: Micromachining and Microfabrication, 2001, San Francisco, CA, United States

Abstract

Piezoelectric aluminum nitride (AlN) thin films have been developed to realize ultrasonic transducers. AlN up to 1.5m is deposited at low temperature (140 degree(s)C) by reactive DC magnetron sputtering of an Al target in argon and nitrogen on Si, Si/SiO₂/Al, and Si/Al substrates, and is wet etched (rates from 0.1 micrometers /min to 0.2 micrometers /min and selectivity of 1:10 with Al, and no etching with Si). SiO₂/Al/AlN/Al, Al/AlN/Al and Si/AlN/Al square and circular membranes, from 10 micrometers to 1.5 mm size are fabricated using silicon deep reactive ion etching (DRIE), which gives etch profiles about 90, which allows larger integration density than wet anisotropic etching for ultrasonic transducers arrays. By varying size and thickness of membranes, resonance frequencies from 10 kHz to 20 MHz are expected, acoustic and electrical measurements are in progress. Ultrasonic transducers using this technology will be used to measure flows velocity by Doppler method. Other potential applications for ultrasonic transducers include medical ultrasounds and sonar. Other structures are also in progress such as Thin Film Bulk Acoustic Resonator (TFBAR), and Lamb wave devices using this technology.

Citation Download Citation

Laurie Valbin and Laure Sevely "Piezoelectric aluminum nitride thin films for ultrasonic transducers", Proc. SPIE 4559, MEMS Components and Applications for Industry, Automobiles, Aerospace, and Communication, (1 October 2001); https://doi.org/10.1117/12.443023

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available