Patent ID: 7422928

Claim:
A process for fabricating a micro-electro-mechanical system composed of fixed components fixedly supported on a base and movable components movably supported on said base; said process comprising the steps of: 1) providing a upper semiconductor substrate ( 10 ) and a lower substrate ( 20 ) which defines said base; 2) selectively etching a top layer ( 12 ) in said upper semiconductor substrate to form therein a plurality of posts which project commonly from a bottom layer ( 14 ) of said upper semiconductor substrate, said posts including said fixed components ( 30 ) to be fixed to said lower substrate and said movable components ( 40 ) which are resiliently coupled to one or more of said fixed components to be movable relative to said lower substrate; 3) selectively etching a top surface of said lower substrate to form therein at least one recess ( 22 ); 4) bonding said upper semiconductor substrate on top of said lower substrate with said upper semiconductor substrate upside down in such a manner as to place said fixed components directly on said lower substrate and to place said movable components upwardly of said at least one recess; and 5) removing said bottom layer from said upper semiconductor substrate to release said movable components from said bottom layer for floating said movable components above said at least one recess and allowing them to move relative to said lower substrate, while keeping said fixed components fixed to the top of said lower substrate.