Wafer-level Packaging of Solid-state Biosensor, Microfluidics, and Through-Silicon Via

A biosensor system package comprising:

• a transistor structure in a semiconductor layer having a front side and a back side, the transistor structure comprising a channel region;
• a multi-layer interconnect (MLI) structure on the front side of the semiconductor layer comprising a first conductive line and a second conductive line at a first metal (M1) layer, the transistor structure being electrically connected to the MLI structure;
• a carrier substrate on the MLI structure;
• a buried oxide (BOX) layer on the back side of the semiconductor layer, wherein the buried oxide layer has an opening, a first bonding trench, and a second bonding trench on the back side of the channel region, and wherein an interface layer covers the back side over the channel region;
• a microfluidic channel cap structure attached to the first conductive line and the second conductive line;
• and
• a second through substrate via (TSV) structure extending through the microfluidic channel cap structure and configured to provide an electrical connection between the MLI structure and a separate die.

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 microfluidic channel cap structure;
• bonding the microfluidic channel cap structure to the BOX layer;
• thinning the carrier substrate;
• creating a first through substrate via (TSV) structure extending through the carrier substrate, the first TSV structure electrically connected to the MLI structure;
• and
• thinning the microfluidic channel cap structure to form at least one port for inflow and outflow of fluid samples.