Patent ID: 8421170
Filing Date: 2013-04-16
Classification: B06B,B81B,B81C,Y10T

Abstract:
1. A method for microfabrication of a capacitive micromachined ultrasonic transducer (CMUT) containing at least one CMUT cell comprising the steps preparing a substrate by preparing a membrane by assembling the membrane on the substrate such that the intermediate layer is facing cavities, by plasma-activated direct wafer bonding between the intermediate layer and the cavity walls; removing the substrate of the diamond layer; and forming at least one first electrode connection; wherein said intermediate layer is of a material with high chemical affinity towards the cavity wall material, the surface roughness of said intermediate layer is decreased by polishing to below 0.5 nm, and the thickness of said intermediate layer after polishing is determined such that the behavior of the membrane is determined by the diamond layer.