Biosensor System with Integrated Microneedle

A biosensor system package comprising:

• a biosensor structure in a semiconductor layer having a front side and a back side, the biosensor structure comprising a channel region and an interface layer covering the back side over the channel region;
• a buried oxide (BOX) layer on the back side of the semiconductor layer, wherein the buried oxide layer has an opening on the back side of the channel region, and the interface layer is exposed in the opening;
• a multi-layer interconnect (MLI) structure on the front side of the semiconductor layer, the biosensor structure being electrically connected to the MLI structure;
• a reference electrode connected to the MLI structure and configured to provide a reference potential;
• and
• a cap structure attached to the buried oxide layer, the cap structure comprising a microneedle.

A method of fabricating a biosensor system package comprising:

• providing a substrate, the substrate comprising a semiconductor layer having a front side and a back side, a buried oxide (BOX) layer at the back side, and a bulk silicon layer at the back side;
• forming a transistor structure on the substrate, wherein a channel region of the transistor structure is in the semiconductor layer;
• forming a multi-layer interconnect (MLI) structure on the front side of the semiconductor layer, wherein the MLI structure is electrically connected to the transistor structure;
• attaching a carrier substrate to the MLI structure;
• removing the bulk silicon layer;
• etching the buried oxide layer to form an opening at the back side over the channel region;
• depositing an interface layer on the back side over the channel region;
• fabricating a cap structure using a complementary metal-oxide-semiconductor (CMOS) compatible process flow;
• bonding the cap structure to the BOX layer;
• and
• creating a microneedle on the cap structure.