基于腔体SOI的CMUT工艺方法及性能研究

Research on CMUT Process Method and Performance Based on Cavity SOI

摘要:

针对目前水下超声检测对超声探头结构尺寸、灵敏度及可靠性等方面的更高要求，提出了一种基于腔体绝缘体上硅工艺设计并制备微小电容式微机械超声换能器（CMUT）的方法，并通过封装完成了 CMUT 电学性能测试以及水下性能表征。测试结果表明，此方法制备的 CMUT 具有更高的良品率与一致性，且其发送电压响应级为 169. 03 dB、接收灵敏度为?211. 31 dB、相对带宽为 121%，表现出优异的灵敏度特性与指向性（?6 dB 波束宽度为 8°）。这种新型的 CMUT 制备方法为未来 CMUT 高密度集成及水下超声检测提供了理论支持与依据。

Abstract:

Currently， underwater ultrasonic testing places higher demands on the structural size， sensitivity， and reliability of ultrasonic probes. This article proposes a method for designing and fabricating a capacitive micromechanical ultrasonic transducer （CMUT） based on cavity SOI technology and completes CMUT electrical performance testing and underwater performance characterization through packaging. The test results show that the CMUT fabricated using this method achieves higher yield and consistency. Its transmission voltage response level is 169. 03 dB， reception sensitivity is ?211. 31 dB， and relative bandwidth is 121%， demonstrating excellent sensitivity characteristics and directionality （with a ? 6 dB beam width of 8°）. This novel CMUT fabrication method provides theoretical support and a foundation for future high-density CMUT integration and underwater ultrasonic testing.