Large-Scale and High-Density pMUT Array Based on Isolated Sol-Gel PZT Membranes for Fingerprint Imaging
Large-Scale and High-Density pMUT Array Based on Isolated Sol-Gel PZT Membranes for Fingerprint Imaging
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DOI：
10.1149/2.0891707jes
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发表时间：
2017-01-01
影响因子：
3.9
通讯作者：
Ren, Tian-Ling
中科院分区：
文献类型：
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作者：
Chen, Yuan-Quan;Li, Yu-Xing;Ren, Tian-Ling
在这项工作中，我们提出了一种新的超声换能器阵列的基础上的50 × 50压电微机械超声换能器（pMUT）的阵列。该结构是专门为指纹成像应用而设计的。pMUTs阵列的制作与隔离的压电锆钛酸铅（PZT）电池，以减少相邻单元之间的串扰，并释放深硅蚀刻从背面。pMUT的细胞大小和间距分别为50 μ m和100 μ m。在溶胶-凝胶法制备PZT薄膜的过程中，采用逐层退火的方法代替了一次退火。pMUT的谐振频率约为24.82 MHz，与模拟的25.02 MHz吻合良好。换能器的有效机电耦合系数k（eff）为0.1293，机械品质因数Q为198。建立了换能器的等效电路并进行了分析。拟合的导纳圆与实验结果吻合较好。这种pMUT阵列的展示对于大规模、高密度和高频率的指纹成像具有深远的潜力。(C)作者（S）2017由ECS发布。All rights reserved.
In this work, we proposed a novel ultrasonic transducer array based on an array of 50 x 50 piezoelectric micromachined ultrasonic transducers (pMUTs). The structure was specially designed for fingerprint imaging application. The pMUTs array were fabricated with isolated piezoelectric lead zirconate titanate (PZT) cells to reduce the crosstalk between adjacent units, and released by deep-silicon etching from the back side. The cell size and pitch of pMUTs were 50 mu m and 100 mu m, respectively. Layer-by-layer annealing method was used instead of one-time annealing during the fabrication of sol-gel based PZT film. The resonance frequency of the pMUT was about 24.82 MHz which agreed well with simulated 25.02 MHz. Besides, the effective electro-mechanical coupling coefficient (k(eff)) and mechanical quality factor (Q factor) of the transducer were 0.1293 and 198, respectively. The equivalent circuit of the transducer was established and analyzed. The fitted admittance circle agreed well with the experimental result. This demonstration of pMUTs array has profound potential for large-scale, high-density, and high-frequency fingerprint imaging. (C) The Author(s) 2017. Published by ECS. All rights reserved.