Schottky barrier tunneling field effect transistor biosensor with tooth-shaped channel and multiple tunneling regions

Abstract

A Schottky barrier tunneling field effect transistor biosensor with a tooth-shaped channel and multiple tunneling regions comprises the tooth-shaped channel, a source electrode is arranged on a protruding part of the tooth-shaped channel, grid electrodes are arranged in a concave part of the tooth-shaped channel and on the two outer sides of the tooth-shaped channel, a biomolecule detection cavity is formed between the grid electrodes and the tooth-shaped channel, and a plurality of tunneling regions are arranged in the biomolecule detection cavity. A gate dielectric layer is arranged at the bottom of the biomolecule detection cavity, and a drain electrode is arranged at the bottom of the tooth-shaped channel; the device is provided with more sources through the channels of the tooth-shaped structure, multi-directional conduction of current is formed, the working speed is increased, the biomolecule detection cavity is oppositely arranged on one sides of the three sources, more Schottky tunneling areas can be generated, the probability of Schottky tunneling of carriers is increased, and the sensitivity of the sensor is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor devices, and in particular relates to a Schottky barrier tunneling field effect transistor biosensor with a toothed channel and multiple tunneling regions. Background Art

[0002] The aging global population and increasing complexity of diseases are placing higher demands on point-of-care (POCT) technology. Traditional molecular diagnostic techniques (such as PCR and ELISA) are difficult to meet the needs of primary care due to their cumbersome procedures, lengthy processing times (hours to days), and expensive equipment. Field-effect transistor (FET)-based biosensors, which directly detect biomolecules through electrical signals, offer the advantages of being label-free and highly sensitive, making them a promising breakthrough.

[0003] Among them, tunneling field-effect transistors (TFETs) have attracted much attention due to their subthreshold swing (SS < 60mV / dec) and low power consumption. However, their preparation relies on high-precision ion implantation to form a steep doping interface, which is complex and difficult to mass-produce. Interface defect states can easily lead to performance drift. In comparison, Schottky tunneling field-effect transistors (SB-FETs) use metal silicide source and drain electrodes, simplifying the doping steps through a self-aligned process and reducing the interface state density. The low work function characteristics of metal silicide enhance carrier transport efficiency, while the metal passivation layer can suppress environmental noise interference and improve device stability and repeatability. The high drain current (>10-6A) and low series resistance characteristics of SB-FETs give them significant advantages in miniaturized, low-power POCT devices, providing a new path for the development of high-throughput biosensing platforms.

[0004] Patent application number 202011516842.4 discloses a "biosensor based on a nanosheet stack field-effect transistor and its preparation method." Three vertically stacked nanosheets form a channel, with a nanocavity etched near the source end. This structure overcomes the short-channel effect, but suffers from lower sensitivity.

[0005] The IEEE SENSORS JOURNAL published a technology solution, "Simulation Study of DualMetal-Gate Inverted T-Shaped TFET for Label-Free Biosensing." The biosensor features a T-shaped channel with two drain regions located at either end of the T, effectively suppressing the bipolar effect. However, the on-state current is relatively low.

[0006] The journal IEEE Transactions on Nanobioscience published a technical solution, "L-Shaped High-Performance Schottky BarrierFET as Dielectrically Modulated Label-Free Biosensor." This device utilizes an L-shaped vertical channel structure, with the source and drain electrodes made of ErSi1.7 material forming Schottky contacts with the channel. This device exhibits high sensitivity, but the fabrication process is complex.

[0007] Existing biosensors based on devices such as MOSFET and TFET have complex preparation processes and low drain currents, which cannot improve the operating speed and sensing sensitivity of the devices. Summary of the Invention

[0008] In order to overcome the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a Schottky barrier tunneling field-effect transistor biosensor with a serrated channel and multiple tunneling regions. The serrated channel structure enables the device to have more source electrodes, forming multi-directional conduction of current and improving the operating speed. The biomolecule detection cavity is placed on one side of the three source electrodes to generate more Schottky tunneling regions, increase the probability of carriers undergoing Schottky tunneling, and improve the sensitivity of the sensor.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] A Schottky barrier tunneling field-effect transistor biosensor with a serrated channel and multiple tunneling regions comprises: a serrated channel 1, a source electrode 2 provided on a protruding portion of the serrated channel 1, a gate electrode 4 provided in a recess of the serrated channel 1 and on both outer sides of the serrated channel 1, a biomolecule detection cavity 6 provided between the gate electrode 4 and the serrated channel 1, a gate dielectric layer 5 provided at the bottom of the biomolecule detection cavity 6, and a drain electrode 3 provided at the bottom of the serrated channel 1.

[0011] The number of protrusions of the toothed groove 1 is greater than or equal to three.

[0012] The gate dielectric layer 5 is made of any one of HfO 2 , Al 2 O 3 or SiO 2 .

[0013] There are multiple biomolecule detection cavities 6 etched on the gate dielectric layer 5 .

[0014] The source electrode 2 and the drain electrode 3 are made of metal silicide, including erbium silicide and nickel silicide.

[0015] The gate 4 is made of metal materials including hafnium and aluminum.

[0016] When biomolecules are injected into the biomolecule detection cavity 6, the drain current sensitivity is:

[0017]

[0018] in, is the drain current sensitivity, I bio ds The drain current when biomolecules are injected into the biomolecule detection cavity 6, I air ds It is the drain current when no biomolecules are injected into the biomolecule detection cavity 6 .

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The use of a tooth-shaped channel structure can enable the device to have more source electrodes, forming a multi-directional conduction of current, increasing the drain current of the device and improving the working speed. Figure 2 As shown, the drain saturation current of the traditional structure with K=12 is 2.3×10-6A / μm, and the drain saturation current of the present invention with K=12 is 6.4×10-6A / μm. Compared with the traditional structure, the drain saturation current of the present invention is increased by 2.8 times.

[0021] 2. The gate 4 and gate dielectric layer 5, positioned in the recesses of the toothed channel 1, can be etched to create more biomolecule detection cavities 6 in the gate dielectric layer 5, generating more Schottky tunneling regions. This increases the probability of carrier Schottky tunneling and improves sensor sensitivity. Calculations show that when K = 12, the drain current sensitivity of the conventional structure is 3 × 10⁵. When K = 12, the drain current sensitivity of the present invention is 9.2 × 10⁵. Therefore, the drain current sensitivity of the present invention at K = 12 is increased by 3.1 times.

[0022] 3. The source and drain are made of metal silicide materials to reduce the source-drain contact resistance, reduce dynamic power consumption and improve switching speed.

[0023] In summary, the Schottky barrier tunneling field-effect transistor biosensor with a serrated channel and multiple tunneling regions of the present invention adopts a serrated channel structure, which can provide the device with more source electrodes, form multi-directional current conduction, increase the drain current of the device, and improve the operating speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural diagram of the present invention.

[0025] Figure 2 This is a curve diagram of the computer-aided design software simulation characteristics of the present invention.

[0026] Markings in the figure: 1 is a toothed channel, 2 is a source, 3 is a drain, 4 is a gate, 5 is a gate dielectric layer, and 6 is a biomolecule detection cavity. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0028] The working principle of the present invention is:

[0029] See also Figure 1 A Schottky barrier tunneling field-effect transistor biosensor with a serrated channel and multiple tunneling regions includes: a serrated channel 1. The serrated channel structure allows the device to have more source electrodes, forming multi-directional current conduction, increasing the drain current of the device, and improving the operating speed; a source electrode 2 is provided on the protruding portion of the serrated channel 1, a gate electrode 4 is provided in the recess of the serrated channel 1 and on both sides of the serrated channel 1, a biomolecule detection cavity 6 is provided between the gate electrode 4 and the serrated channel 1, a gate dielectric layer 5 is provided at the bottom of the biomolecule detection cavity 6, and a drain electrode 3 is provided at the bottom of the serrated channel 1.

[0030] The number of protrusions of the toothed groove 1 is greater than or equal to three.

[0031] The gate dielectric layer 5 is made of any one of HfO 2 , Al 2 O 3 or SiO 2 .

[0032] There are multiple biomolecule detection cavities 6 etched on the gate dielectric layer 5 .

[0033] The source electrode 2 and the drain electrode 3 are made of metal silicide, including erbium silicide and nickel silicide.

[0034] The gate 4 is made of metal materials including hafnium and aluminum.

[0035] Drain current sensitivity is an important indicator for detecting the performance of biosensors. The drain current sensitivity formula is: Among them S Ids is the drain current sensitivity, I bio ds Drain current when biomolecules are injected into the cavity, I air ds It is the drain current when no biomolecules are injected into the biomolecule detection cavity 6 .

[0036] The working principle of the present invention is:

[0037] The present invention utilizes a serrated channel 1, thereby introducing multiple source electrodes 2, resulting in multidirectional current conduction, increasing the device's drain current and boosting operating speed. Furthermore, the multiple biomolecule detection cavities 6 positioned opposite one another on either side of the source electrodes 2 create more Schottky tunneling regions, increasing the probability of carrier Schottky tunneling and improving sensor sensitivity. Schottky barrier tunneling field-effect transistors use metal silicide as the source and drain materials to form Schottky contacts. Increasing gate voltage exacerbates channel band bending, reduces the tunneling barrier width, and exponentially increases the tunneling probability.

[0038] Simulation experiment:

[0039] See also Figure 2 Using Sentaurus TCAD simulation software, simulation results for a Schottky barrier tunneling field-effect transistor biosensor with a serrated channel and multiple tunneling regions were obtained. Using Sentaurus TCAD's SDE tool, the structure of the biosensor of the present invention was simulated. The serrated channel structure allows the device to have more source electrodes, resulting in multidirectional current conduction, increasing the device's drain current and improving operating speed. Mathematical physics equations were then solved, and the transfer characteristics of the biosensor were simulated using Sentaurus TCAD's SDEVICE tool. Using the Poisson equation, current density equation, and electron-hole continuity equation, a quantitative relationship between the device's electrostatic potential distribution, carrier transport, and electrical output characteristics was established, and the parameters of the electrical properties were visualized. The Shockley-Read-Hall (SRH) model is used to characterize defect-assisted recombination, and the Auger recombination model is introduced to describe non-radiative recombination under high carrier concentrations. The Electron Mobility and Hole Mobility models (including doping dependence, high-field saturation, and interface scattering effects) are used to accurately simulate the carrier transport dynamics. The Band Gap Narrowing (BGN) model is activated to quantify the high-doped source / drain region (>1×10 19 cm -3 ) bandgap shrinkage effect. Through simulation, it can be obtained that the drain saturation current of the present invention when K=12 is 6.4×10 -6 A / μm, the drain saturation current of the traditional structure K=12 is 2.3×10 -6 A / μm, compared with the traditional structure, the drain saturation current of the present invention is increased by 2.8 times. When K=12, the drain current sensitivity of the traditional structure is 3×10 5 The drain current sensitivity of the present invention is 9.2×10 5 Therefore, the drain current sensitivity of the present invention is improved by 3.1 times when K = 12. In summary, the Schottky barrier tunneling field effect transistor biosensor with a dentate channel and multiple tunneling regions has improved performance compared to the traditional structure.

[0040] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with this technical field within the technical scope disclosed by the present invention and within the spirit and principles of the present invention should be covered by the scope of protection of the present invention.

Claims

1. A Schottky barrier tunneling field effect transistor biosensor having a toothed channel and multiple tunneling regions, characterized in that: The invention comprises a tooth-shaped channel (1), a source electrode (2) is provided on a protruding portion of the tooth-shaped channel (1), a gate electrode (4) is provided in a recess of the tooth-shaped channel 1 and on both outer sides of the tooth-shaped channel (1), a biomolecule detection cavity (6) is provided between the gate electrode (4) and the tooth-shaped channel (1), a gate dielectric layer (5) is provided at the bottom of the biomolecule detection cavity (6), and a drain electrode (3) is provided at the bottom of the tooth-shaped channel (1).

2. The Schottky barrier tunneling field effect transistor biosensor having a toothed channel and multiple tunneling regions according to claim 1, characterized in that: The number of protrusions of the toothed channel (1) is greater than or equal to three.

3. The Schottky barrier tunneling field effect transistor biosensor having a toothed channel and multiple tunneling regions according to claim 1, characterized in that: The gate dielectric layer (5) is made of any one of HfO2, Al2O3 or SiO2.

4. The Schottky barrier tunneling field effect transistor biosensor having a toothed channel and multiple tunneling regions according to claim 1, characterized in that: There are a plurality of biomolecule detection cavities (6) etched on the gate dielectric layer (5).

5. The Schottky barrier tunneling field effect transistor biosensor having a toothed channel and multiple tunneling regions according to claim 1, characterized in that: The source electrode (2) and the drain electrode (3) are made of metal silicide, including erbium silicide and nickel silicide.

6. The Schottky barrier tunneling field effect transistor biosensor having a toothed channel and multiple tunneling regions according to claim 1, characterized in that: The gate (4) is made of metal materials including hafnium and aluminum.

7. The Schottky barrier tunneling field effect transistor biosensor having a dentate channel and multiple tunneling regions according to claim 1, characterized in that: When biomolecules are injected into the biomolecule detection cavity (6), the drain current sensitivity is: in, is the drain current sensitivity, I bio ds The drain current when biomolecules are injected into the biomolecule detection cavity 6, I air ds It is the drain current when no biomolecules are injected into the biomolecule detection cavity (6).

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