A Multiple-Scan Focusing Method for Radio Frequency Bulk Acoustic Wave Device Observation by Laser Probe System

作者:Wu Nan*; Hashimoto Ken ya; Omori Tatsuya; Yamaguchi Masatsune
来源:Japanese Journal of Applied Physics, 2010, 49(7): 07HD10.
DOI:10.1143/JJAP.49.07HD10

摘要

This paper proposes a focusing method based on multiple scanning of a device surface to be observed, which is particularly-suitable for a fast-mechanical-scanning and phase-sensitive laser probe for radio frequency (RF) surface and bulk acoustic wave (SAW/BAW) devices. When high spatial resolution is required for the observation, one needs an objective lens of large magnifying power with extremely shallow focal depth. Accordingly, an uneven surface and tiny inclination of a BAW device cause acquired images a considerable defocus, by which it is difficult to obtain precise and reliable field quantities related to acoustic waves in the device. The proposed method is shown to be most effective in avoiding this sort of defocus and able to focus the entire surface. By this method, for example, we could clearly observe power leakage in an FBAR structure.

  • 出版日期2010

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