Systems for buried electrical feedthroughs in a glass-silicon MEMS process

A micro electromechanical system (MEMS) gyroscope comprising:

• a housing;
• gyroscope electronics located within said housing;
• a structure defining a hermetically sealed cavity within said housing;
• and
• a tuning fork gyroscope located within the hermetically sealed cavity, said structure comprising:
• a plurality of electrical feedthroughs providing electrical connections between said gyroscope electronics and said tuning fork gyroscope;
• a glass substrate comprising recesses formed therein, said recesses being where said electrical feedthroughs pass into and out of the hermetically sealed cavity;
• a glass layer deposited over said substrate, said glass layer further deposited over said electrical feedthroughs in said recesses, said glass layer planarized to a level of a portion of said electrical feedthroughs around said recesses;
• and
• silicon bonded to said planarized glass layer, said silicon fabricated such that a portion of each said electrical feedthrough is within the hermetically sealed cavity and a portion of each said electrical feedthrough is outside the hermetically sealed cavity.

A structure having a hermetically sealed cavity therein, said structure having at least one electrically conductive path passing from outside of the cavity to the sealed cavity, said structure comprising:

• a glass substrate comprising recesses formed therein where electrical signals are to pass into the sealed cavity and an upper surface;
• conductive leads deposited on said recesses;
• a glass deposit on said conductive leads, said glass deposit comprising an upper surface planarized to a level of said upper surface of said substrate;
• and
• silicon bonded to said upper surface of said glass deposit and said upper surface of said substrate, said silicon fabricated such that a portion of each said conductive lead is within the sealed cavity and a portion of each said conductive lead is outside the sealed cavity.