# US 2021/0239647 A1 · Wafer-level Packaging of Solid-state Biosensor, Microfluidics, and Through-Silicon Via

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- Number: US 2021/0239647 A1
- Document ID: US20210239647A1
- Status: Published application
- Kind: A1
- Application number: 17/095,151
- Filed: 2020-11-11
- Published: 2021-08-05
- Earliest claimed: 2020-01-30
- Assignees: Taiwan Semiconductor Manufacturing Company, Ltd.
- Applicants: Taiwan Semiconductor Manufacturing Company, Ltd.
- Inventors: Allen Timothy Chang; Jui-Cheng Huang; Wen-Chuan Tai; Yu-Jie Huang
- Web page: https://patentgrep.com/patent/US20210239647A1

## CPC

- B81C 1/00246: {Monolithic integration, i.e. micromechanical structure and electronic processing unit are integrated on the same substrate}
- G01N 27/4145: {specially adapted for biomolecules, e.g. gate electrode with immobilised receptors}
- B01L 3/502707: {characterised by the manufacture of the container or its components}
- B01L 3/502715: {characterised by interfacing components, e.g. fluidic, electrical, optical or mechanical interfaces}
- B81B 7/0061: {suitable for fluid transfer from the MEMS out of the package or vice versa, e.g. transfer of liquid, gas, sound}
- B01L 2300/023: Sending and receiving of information, e.g. using Bluetooth®
- B01L 2300/0636: Integrated biosensor, microarrays
- B01L 2300/0645: Electrodes
- B81B 2201/058: Microfluidics not provided for in B81B2201/051 - B81B2201/054
- B81B 2207/015: the micromechanical device and the control or processing electronics being integrated on the same substrate
- B81B 2207/096: through the substrate
- H10W 20/20: Interconnections within wafers or substrates, e.g. through-silicon vias [TSV]
- H10W 20/42: Vias, e.g. via plugs
- B81C: PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS (making microcapsules or microballoons B01J13/02; processes or apparatus specially adapted for the manufacture or treatment of piezoelectric, electrostrictive or magnetostrictive elements per se H10N30/01)
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)
- B01L: CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
- B81B: MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES (piezoelectric, electrostrictive or magnetostrictive elements per se H10N30/00, H10N35/00)
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

A biosensor system package includes: 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, the transistor structure being electrically connected to the MLI structure; a carrier substrate on the MLI structure; a first through substrate via (TSV) structure extending though the carrier substrate and configured to provide an electrical connection between the MLI structure and a separate die; 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 an interface layer covers the back side over the channel region; and a microfluidic channel cap structure attached to the buried oxide layer.

## Claims

### Claim 1

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, the transistor structure being electrically connected to the MLI structure;
a carrier substrate on the MLI structure;
a first through substrate via (TSV) structure extending though the carrier substrate and configured to provide an electrical connection between the MLI structure and a separate die;
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 an interface layer covers the back side over the channel region; and
a microfluidic channel cap structure attached to the buried oxide layer.

### Claim 2 (depends on 1)

The biosensor system package of claim 1, wherein the microfluidic channel cap structure is fabricated using a complementary metal-oxide-semiconductor (CMOS) compatible process flow.

### Claim 3 (depends on 1)

The biosensor system package of claim 1, wherein the microfluidic channel cap structure further comprises:
a cap structure substrate having a chamber configured to accommodate fluid samples to be tested; and
at least one port connecting the chamber and for inflow and outflow of the fluid samples.

### Claim 4 (depends on 3)

The biosensor system package of claim 3, wherein the microfluidic channel cap structure further comprises:
a high-k oxide material layer covering a bottom and sidewalls of the chamber.

### Claim 5 (depends on 3)

The biosensor system package of claim 3, wherein the cap structure substrate has bonding areas interfacing with bonding sites of the buried oxide layer.

### Claim 6 (depends on 1)

The biosensor system package of claim 1, wherein the MLI structure comprises:
a plurality of interposing dielectric layers;
a plurality of conductive lines, each conductive line disposed in one of the plurality of interposing dielectric layers; and
a plurality conductive vertical interconnect access (VIA) structures connecting the plurality of conductive lines.

### Claim 7 (depends on 1)

The biosensor system package of claim 1, wherein the first TSV structure comprises:
a conductive material;
a liner isolating the conductive material from the carrier substrate; and
a diffusion barrier layer between the conductive material and the liner.

### Claim 8 (depends on 1)

The biosensor system package of claim 1, further comprising:
the separate die, wherein the separate die is electrically connected to the first TSV structure and configured to process data collected by the transistor structure.

### Claim 9 (depends on 1)

The biosensor system package of claim 1, wherein the interface layer is a high-k material layer.

### Claim 10 (depends on 3)

The biosensor system package of claim 3, wherein the interface layer comprises a layer of capture reagent capable of binding a target analyte in the fluid samples.

### Claim 11

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.

### Claim 12 (depends on 11)

The biosensor system package of claim 11, wherein the microfluidic channel cap structure is fabricated using a complementary metal-oxide-semiconductor (CMOS) compatible process flow.

### Claim 13 (depends on 11)

The biosensor system package of claim 11, wherein the microfluidic channel cap structure further comprises:
a cap structure substrate having a chamber configured to accommodate fluid samples to be tested;
at least one port connecting the chamber and for inflow and outflow of the fluid samples;
a pillar structure accommodated in a first bonding trench and protruding toward the first conductive line, wherein the pillar structure is electrically connected to the second TSV structure; and
a bond ring accommodated in a second bonding trench and protruding toward the second conductive line.

### Claim 14 (depends on 13)

The biosensor system package of claim 13, wherein the pillar structure and the bond ring both comprise a conductive layer and an intermediate layer, the intermediate layer used for eutectic bonding.

### Claim 15 (depends on 14)

The biosensor system package of claim 14, wherein the conductive layer is made of polysilicon, and the intermediate layer is made of germanium.

### Claim 16 (depends on 13)

The biosensor system package of claim 13, wherein the second TSV structure comprises:
a portion of the cap structure substrate, wherein the portion of the cap structure substrate is highly doped; and
at least one oxide layer surrounding the portion of the cap structure substrate.

### Claim 17 (depends on 11)

The biosensor system package of claim 11, further comprising:
the separate die, wherein the die is electrically connected to the second TSV structure and configured to process data collected by the transistor structure.

### Claim 18 (depends on 11)

The biosensor system package of claim 11, wherein the interface layer is a high-k material layer.

### Claim 19

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.

### Claim 20 (depends on 19)

The method of fabricating a biosensor system package of claim 19, wherein the fabricating a microfluidic channel cap structure comprises:
providing a cap structure substrate;
etching the cap structure substrate to predefine a global cavity region corresponding to a chamber;
depositing a hard mask on bonding areas of the cap structure substrate;
patterning and etching a portion of the global cavity region to form at least one channel corresponding to the at least one port;
etching the entire global cavity region to form the chamber; and
removing the hard mask.