Patent ID: 6539798
Filing Date: 2003-04-01
Classification: G01P

Abstract:
A method of producing an acceleration threshold sensor including a supporting device, a seismic mass, and a connecting device with the aid of which the seismic mass is attached to the supporting device, said connecting device being provided with a predetermined breaking point interrupting the connection between the seismic mass and the supporting device when said seismic mass is subjected to an acceleration exceeding a predetermined acceleration, said method comprising the following steps:a) providing a SIMOX substrate or another SOI substrate or a silicon substrate provided with a silicon oxide layer or a silicon start layer; b) depositing a silicon epitaxial layer or a silicon CVD layer on a thin silicon film of the SIMOX substrate or on an oxide layer of the SOI substrate or on the silicon start layer; c) producing a conducting-path system and a contacting system on the silicon layer deposited in step b); d) producing and structuring a passivation layer over the silicon layer deposited in step b) and the conducting-path system and the contacting system, with the property that this layer acts as an etching mask during a subsequent trench-etching process; e) producing a back mask and carrying out a back-etching process, an oxide layer of the SIMOX substrate, an oxide layer of the SOI substrate or an oxide layer provided on the silicon start layer acting as an etch stop; f) carrying out etching from the back of the structure for removing the oxide layer; and g) carrying out a subsequent trench-etching process so as to form and expose the seismic mass and the connecting device of the acceleration threshold sensor.