Rough back surface is investigated to decrease the reverberation noise in ultrasonic imaging. Silicon crystal is selected as the backing substrate of the ultrasonic transducer because rough structure is convenient to be fabricated on silicon substrate using microfabrication technologies. Different dimensions of rough boundaries are designed and simulated to scatter the undesired waves based on finite element method modeling. Transient analysis indicates that a rough surface whose dimension (including depth and width) is around 1.0 λ should be considered to scatter a majority of incident waves.
