该文设计、制作并测试了一种用于实时三维超声成像的电容式微机械超声换能器(CMUT)二维面阵。根据二维面阵指向性分析, 设计了中心频率1 MHz、阵元间距0.7λ(λ为波长)的16×16阵元CMUT二维面阵, 并利用硅-绝缘体上硅(Si-SOI)键合工艺完成了CMUT二维面阵的加工。通过对CMUT二维面阵进行电容-电压(C-V)测试, 发现静态电容测试值与设计值基本一致, 测量了CMUT二维面阵中64个阵元的电容, 测量的平均电容为26.3 pF, 其标准差为4.27 pF, 验证了所制造的器件具有良好的均匀性。在水中测试了CMUT二维面阵的超声发射和接收功能, 得到测试距离与实际距离偏差不到1%, 实验表明, 不同距离下CMUT的发射和接收能力良好。

In this paper, a CMUT 2D array for real-time 3D ultrasound imaging is designed, fabricated and tested. According to the directivity analysis of 2D array, a 16×16 CMUT 2D array with center frequency of 1 MHz and element spacing of 0.7λ ( is the wavelength) is designed, and the processing of CMUT 2D array is completed by Si-SOI bonding process. Through the C-V test of the CMUT 2D array, it is found that the static capacitance test value is consistent with the design value. The capacitance of 64 elements in the CMUT 2D array is measured. The average capacitance is 26.3 pF, and the standard deviation is 4.27 pF, which verifies that the device has good uniformity. The ultrasonic transmitting and receiving function of CMUT 2D array is tested in water, and the deviation between the test distance and the actual distance is less than 1%. The experiment shows that the transmitting and receiving ability of CMUT is good at different distances.