CMOS compatible BioFET
The present disclosure provides a bio-field effect transistor (BioFET) and a method of fabricating a BioFET device. The method includes forming a BioFET using one or more process steps compatible with or typical to a complementary metal-oxide-semiconductor (CMOS) process. The BioFET device may include a substrate; a gate structure disposed on a first surface of the substrate and an interface layer formed on the second surface of the substrate. The interface layer may allow for a receptor to be placed on the interface layer to detect the presence of a biomolecule or bio-entity.
1 . A semiconductor device, comprising:
a biologically sensitive field-effect transistor (BioFET) comprising:
a source/drain region and a channel region disposed in a semiconductor layer,
a gate structure disposed on a first surface of the semiconductor layer and on back surfaces of the channel region and the source/drain region,
an oxide layer disposed on a second surface of the semiconductor layer, and
an interface layer disposed in the oxide layer and on top surfaces of the channel region and the source/drain region; and
an insulating layer with an input/output (I/O) pad disposed on and electrically connected to the gate structure, wherein the I/O pad is non-overlapping with the gate structure.
2 . The semiconductor device of claim 1 , further comprising:
an interlayer dielectric (ILD) layer disposed on the gate structure; and
a substrate bonded to the ILD layer, wherein the insulating layer is disposed between the substrate and the ILD layer.
3 . The semiconductor device of claim 1 , wherein the BioFET further comprises a nitride layer disposed on the oxide layer, and
wherein the interface layer is disposed in an opening of the nitride layer.
4 . The semiconductor device of claim 1 , wherein the interface layer comprises:
a high-k dielectric layer disposed on the exposed surface of the channel region; and
a metal layer disposed on the high-k dielectric layer.
5 . The semiconductor device of claim 1 , wherein the interface layer is disposed directly on the source/drain region and the channel region.
6 . The semiconductor device of claim 1 , wherein the interface layer comprises a gold layer.
7 . The semiconductor device of claim 1 , wherein the interface layer comprises a hafnium oxide layer.
8 . The semiconductor device of claim 1 , further comprising:
a multi-layer interconnect (MLI) structure disposed on the gate structure, wherein the insulating layer is bonded to the MLI structure; and
a substrate bonded to the MLI structure.
9 . The semiconductor device of claim 1 , further comprising a multi-layer interconnect (MLI) structure with a plurality of metal lines disposed between the gate structure and the insulating layer.
10 . The semiconductor device of claim 1 , further comprising:
an interlayer dielectric (ILD) layer disposed on the gate structure;
a metal line disposed in the ILD layer; and
a bonding element disposed on the metal line and configured to electrically connect the metal line to the I/O pad.
11 . A semiconductor device, comprising:
a biologically sensitive field-effect transistor (BioFET) comprising:
a semiconductor layer,
a gate structure disposed on the semiconductor layer,
a first oxide layer disposed on a first side of the gate structure,
a first conductive layer disposed in an opening of the first oxide layer, and
a channel region disposed between the gate structure and the first conductive layer;
a second oxide layer disposed on a second side of the gate structure; and
a second conductive layer disposed in the second oxide layer, wherein the first and second conductive layers comprise materials different from each other, and wherein the first and second conductive layers are non-overlapping with each other.
12 . The semiconductor device of claim 11 , wherein the BioFET further comprises a dielectric layer disposed on the first conductive layer and in the opening of the first oxide layer.
13 . The semiconductor device of claim 11 , wherein the second conductive layer is electrically connected to the gate structure.
14 . The semiconductor device of claim 11 , further comprising an interconnect structure with a plurality of metal lines disposed between the gate structure and the second conductive layer.
15 . The semiconductor device of claim 11 , wherein the first conductive layer comprises gold.
16 . A semiconductor device, comprising:
a biologically sensitive field-effect transistor (BioFET) comprising:
a substrate,
a gate structure disposed on the substrate,
a channel region disposed on a first side of the gate structure,
a dielectric layer disposed on the channel region,
a metal layer disposed on the dielectric layer,
an oxide layer surrounding the dielectric layer and the metal layer, wherein the oxide layer is non-overlapping with the channel region,
a nitride layer disposed on the oxide layer, and
a passivation layer disposed on a second side of the gate structure; and
a conductive bonding layer disposed in the passivation layer and electrically connected to the gate structure, wherein the conductive bonding layer is non-overlapping with the gate structure.
17 . The semiconductor device of claim 16 , further comprising an interconnect structure disposed between the gate structure and the conductive bonding layer.
18 . The semiconductor device of claim 16 , further comprising:
an interlayer dielectric (ILD) layer disposed on the second side of the gate structure;
a metal line disposed in the ILD layer; and
a bonding element disposed on the metal line and configured to electrically connect the metal line to the conductive bonding layer.
19 . The semiconductor device of claim 16 , further comprising a fluidic channel disposed on the nitride layer.
20 . The semiconductor device of claim 16 , further comprising a source/drain region adjacent to the channel region, wherein the dielectric layer extends onto the source/drain region.