Patent ID: 7195946

Claim:
A method for fabricating a semiconductor device that includes a suspended micro-system, said method comprising the steps of: providing a silicon substrate; forming a silicon porous layer above the silicon substrate; oxidizing the silicon porous layer to produce an oxidized porous layer; depositing an oxide layer on the whole device; depositing a first polysilicon layer above the oxide layer; selectively removing the first polysilicon layer, the oxide layer, and the oxidized porous layer up to the silicon substrate so as to create at least one trench that reaches the silicon substrate; depositing a nitride layer on the whole device; depositing a second polysilicon layer on the whole device; selectively removing the second polysilicon layer so as to define areas to free and so as to leave a plurality of hinges that connect a suspended structure to the device; using the second polysilicon layer as a mask to etch the nitride layer, the first polysilicon layer, and the oxide layer; and removing the oxidized porous layer in areas made accessible by the previous steps of selectively removing and using, so as to create an empty space below the suspended structure, the hinges suspending the suspended structure over the empty space and allowing rotation of the suspended structure.