Patent ID: 7074634
Filing Date: 2006-07-11
Classification: H04R

Abstract:
1. A surface micromachining process for manufacturing Electroacoustic transducers, particularly ultrasonic transducers, said transducers comprising a silicon semiconductor substrate ( 1 ), on an upper surface of which one or more membranes ( 18 ) of resilient materials are supported by a structural layer ( 11 ) of insulating material, rigidly connected to said silicon semiconductor substrate ( 1 ), said resilient material having a Young's modulus not lower than 50 GPa, said membranes ( 18 ) being metallised, said transducers including one or more lower electrodes ( 23 , 25 ), rigidly connected to said silicon semiconductor substrate ( 1 ), the process comprising the following steps: A. providing said silicon semiconductor substrate ( B. realising an intermediate product comprising: rigidly connected to an upper surface of said silicon semiconductor substrate ( 1 ), the surfaces of said sacrificial layer ( 8 , 8 ′) and of said structural layer ( 11 ) not in contact with said silicon semiconductor substrate ( 1 ) being substantially co-planar, C. depositing a layer ( D. releasing said membranes ( said process being characterised in that said structural layer (