Trench Isolated CMUT Arrays

Stanford researchers have developed a novel method of fabricating one-dimensional and two-dimensional capacitive micromachined ultrasonic transducer (CMUT) arrays. The method builds a CMUT array on a silicon-on-insulator (SOI) wafer using either the wafer-bonding method or the sacrificial release method. The electrical interconnect to CMUT array elements is provided through the highly conductive silicon substrate. A deep through-wafer trench provides isolation, and a frame structure provides mechanical support for the rigidity of the CMUT array.