PRE-COLLAPSED CAPACITIVE MICRO-MACHINED TRANSDUCER CELL WITH STRESS LAYER

摘要

The present invention relates to a pre-collapsed capacitive micro-machined transducer cell (10) comprising a substrate (12), and a membrane (14) disposed above a total membrane area (Atotal), wherein a cavity (20) is formed between the membrane (14) and the substrate (12), the membrane comprising a hole (15) and an edge portion (14a) surrounding the hole (15). The cell (10) further comprises a stress layer (17) on the membrane (14), the stress layer (17) having a predetermined stress value with respect to the membrane (14), the stress layer (17) being adapted to provide a bending moment on the membrane (14) in a direction towards the substrate (12) such that the edge portion (14a) of the membrane (14) is collapsed to the substrate (12). The present invention further relates to a method of manufacturing such pre-collapsed capacitive micro-machined transducer cell (10).