ULTRASONIC SENSOR AND MEASURING METHOD USING THE SAME, AND METHOD OF MANUFACTURING ULTRASONIC SENSOR

摘要

To provide an ultrasonic sensor that can improve propagation efficiency of an ultrasonic wave, an ultrasonic sensor 1 comprises a substrate 10 where an opening section W is formed; a vibration plate 50 provided on the substrate 10 so as to close the opening section; a piezoelectric element 300 provided on a surface of the vibration plate 50 on an opposite side to the opening section W and having a first electrode 60, a piezoelectric material layer 70, and a second electrode 80; and a reflection layer 71 provided in a space around the piezoelectric element 300 on the surface of the vibration plate on an opposite side to the opening section, to reflect other ultrasonic waves transmitted in a different direction from a transmitted ultrasonic wave transmitted to a measuring target side on an interface between the piezoelectric element and the reflection layer, and having a thickness so as to superimpose other ultrasonic waves on the transmitted ultrasonic wave.