The impact of electrode materials on 1/f noise in piezoelectric AlN contour mode resonators
Abstract
This paper presents a detailed analysis on the impact of electrode materials and dimensions on flicker frequency (1/f) noise in piezoelectric aluminum nitride (AlN) contour mode resonators (CMRs). Flicker frequency noise is a fundamental noise mechanism present in any vibrating mechanical structure, whose sources are not generally well understood. 1 GHz AlN CMRs with three different top electrode materials (Al, Au, and Pt) along with various electrode lengths and widths are fabricated to control the overall damping acting on the device. Specifically, the use of different electrode materials allows control of thermoelastic damping (TED), which is the dominant damping mechanism for high frequency AlN CMRs and largely depends on the thermal properties (i.e. thermal diffusivities and expansion coefficients) of the metal electrode rather than the piezoelectric film. We have measured Q and 1/f noise of 68 resonators and the results show that 1/f noise decreases with increasing Q, with a power law dependence that is about 1/Q4. Interestingly, the noise level also depends on the type of electrode materials. Devices with Pt top electrode demonstrate the best noise performance. Our results help unveiling some of the sources of 1/f noise in these resonators, and indicate that a careful selection of the electrode material and dimensions could reduce 1/f noise not only in AlN-CMRs, but also in various classes of resonators, and thus enable ultra-low noise mechanical resonators for sensing and radio frequency applications.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- May 01, 2018
- Source ID
- 10.1063/1.5024961
Entities
People
- Gianluca Piazza
- Hoe Joon Kim
- Jeronimo Segovia-Fernandez
- Soon In Jung
Organizations
- Carnegie Mellon University
- Daegu Gyeongbuk Institute of Science and Technology
- Defense Advanced Research Projects Agency
- National Research Foundation of Korea