Adaptive contact resistance compensation MoS2 field effect transistor structure

Abstract

The invention discloses an adaptive contact resistance compensation MoS2 field effect transistor structure, and relates to the technical field of MoS2 field effect transistors. The compensation electrode applies optimized bias voltage under accurate regulation and control of the feedback control circuit, and the ultrathin interface modification layer effectively modulates the energy band structure of the MoS2 channel layer, so that the Schottky barrier height and the interface state density at the contact interface between the source electrode and the MoS2 channel layer and between the drain electrode and the MoS2 channel layer can be reduced, carriers can be injected and extracted more efficiently, and the performance of the device is improved. The current carrier injection bottleneck caused by Fermi level pinning in the traditional MoS2FET is effectively overcome; the contact resistance is greatly reduced, ohmic loss on a source-drain path is directly reduced, the working power consumption of the device is reduced, the contact resistance is lower, the carrier injection / extraction process is more efficient, the time required for establishing and dissipating the channel carrier concentration is shortened, and the switching speed of the device is effectively improved.

Description

Technical Field

[0001] This invention relates to the field of MoS2 field-effect transistor technology, and specifically to a MoS2 field-effect transistor structure with adaptive contact resistance compensation. Background Technology

[0002] The MoS2 field-effect transistor (FET) is a two-dimensional semiconductor device based on molybdenum disulfide (MoS2). It controls carrier transport through a gate electric field and features high performance and low power consumption. The MoS2 FET uses MoS2 as the channel material, and controls carrier flow between the source and drain by applying an electric field to the gate (typically composed of metal or metal oxide). Its structure includes three terminals: source, drain, and gate.

[0003] Existing MoS2 field-effect transistor structures typically employ direct contact between metal electrodes and the MoS2 channels. However, the inherent Schottky barrier and high interface state density of MoS2 material lead to a significant increase in source and drain contact resistance, thus limiting carrier injection efficiency and device mobility. This high contact resistance problem is particularly prominent in low-dimensional material devices, causing performance bottlenecks such as decreased drive current, increased power consumption, and slower switching speed. Furthermore, existing structures also face challenges in terms of process compatibility and stability. For example, oxidation or degradation of the metal electrode-MoS2 interface further exacerbates contact resistance inconsistencies, affecting large-scale integrated applications. To address these issues, we propose an adaptive contact resistance compensation MoS2 field-effect transistor structure. Summary of the Invention

[0004] The purpose of this invention is to provide an adaptive contact resistance compensation MoS2 field-effect transistor structure to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention specifically adopts the following technical solution:

[0006] An adaptive contact resistance compensated MoS2 field-effect transistor structure includes:

[0007] A substrate, wherein a source electrode and a drain electrode are respectively disposed on the top of the substrate;

[0008] A MoS2 channel layer is located between the source and the drain, and the source and the drain form an ohmic contact with the MoS2 channel layer for carrier transport.

[0009] A gate is disposed above the MoS2 channel layer and isolated by a gate dielectric layer, and is used to control the flow of charge carriers;

[0010] An adaptive compensation unit is integrated near the source and drain. The adaptive compensation unit has a built-in compensation electrode and a feedback control circuit. The compensation electrode is connected to the MoS2 channel layer through an interface modification layer. The feedback control circuit is used to monitor and adjust the bias voltage of the compensation electrode to achieve dynamic optimization of the contact resistance.

[0011] Furthermore, the substrate is made of high resistivity silicon or sapphire material to provide mechanical support and thermal stability.

[0012] Furthermore, the source and drain electrodes employ a titanium / gold multilayer metal structure to optimize carrier injection efficiency and interface adhesion.

[0013] Furthermore, the compensation electrode is made of a highly conductive metallic material.

[0014] Furthermore, the feedback control circuit includes a resistance monitoring sensor and a microprocessor. The resistance monitoring sensor collects current-voltage characteristic data between the source and the drain in real time. The microprocessor calculates the optimal bias voltage value based on a preset PID control algorithm and outputs it to the compensation electrode.

[0015] Furthermore, the preset PID control algorithm is based on the following function formula:

[0016]

[0017] In the formula, u(t) represents the bias voltage output of the compensation electrode;

[0018] e(t) represents the deviation signal between the real-time measured value of the contact resistance and the preset target value;

[0019] K p K i K d These are the proportional, integral, and differential gain coefficients, respectively.

[0020] Furthermore, the microprocessor dynamically generates an optimal bias voltage signal by calculating the function of the PID control algorithm in real time and applies it to the compensation electrode. Combined with the modulation effect of the interface modification layer on the band structure of the MoS2 channel layer, it effectively offsets the changes in contact resistance caused by environmental fluctuations or device aging, and maintains the stability of the ohmic contact at the source and the drain.

[0021] Furthermore, the interface modification layer is composed of an ultrathin hafnium oxide or boron nitride material, which is used to enhance the interface stability between the MoS2 channel layer and the compensation electrode.

[0022] Furthermore, the adaptive compensation unit also includes a temperature sensor for monitoring changes in the working environment temperature.

[0023] Furthermore, the adaptive compensation unit also includes a temperature compensation module for correcting the effect of ambient temperature changes on contact resistance.

[0024] The beneficial effects of this invention are as follows:

[0025] 1. Under the precise control of the feedback control circuit, the compensation electrode of this invention applies an optimized bias voltage. Combined with the effective modulation of the band structure of the MoS2 channel layer by the ultrathin interface modification layer (such as hafnium oxide or boron nitride), it can reduce the Schottky barrier height and interface state density at the contact interface between the source and drain and the MoS2 channel layer. This allows carriers (electrons or holes) to be injected and extracted more efficiently, effectively overcoming the carrier injection bottleneck caused by Fermi level pinning in traditional MoS2 FETs.

[0026] 2. The significant reduction in contact resistance in this invention directly reduces ohmic losses in the source-drain path, lowering the device's operating power (both static and dynamic power consumption). Lower contact resistance and a more efficient carrier injection / extraction process shorten the time required for channel carrier concentration build-up and dissipation, effectively improving the device's switching speed. The microprocessor-implemented PID algorithm in the feedback control circuit ensures the speed and accuracy of the compensation response, further optimizing dynamic performance.

[0027] 3. The feedback control circuit of this invention monitors the contact resistance state of each device in real time through a resistance monitoring sensor. The microprocessor independently calculates and applies the optimal compensation voltage based on a preset PID algorithm. This closed-loop control mechanism can actively compensate for contact resistance changes caused by factors such as process fluctuations, material inhomogeneity, stress distribution differences, or local temperature gradients. With the cooperation of a temperature sensor and a temperature compensation module, it further corrects for resistance drift caused by changes in ambient temperature or self-heating effects. This adaptive compensation capability ensures that the contact resistance values ​​of different devices and the same device under different operating conditions remain highly consistent, greatly mitigating the impact of contact resistance inconsistency on device performance dispersion, and laying a solid foundation for the reliable realization of large-scale, high-density integrated circuits.

[0028] 4. The interface modification layer of this invention effectively suppresses the generation of defect states and carrier scattering at the interface between the compensation electrode and the MoS2 channel layer, ensuring the long-term stability of charge injection efficiency and compensation signal. The adaptive compensation unit operates continuously and can dynamically track and compensate for the gradual deterioration of contact resistance caused by device aging (such as electromigration and interface degradation) or long-term slow changes in environmental conditions (such as slow temperature drift). Attached Figure Description

[0029] Figure 1 This is a top view of the present invention;

[0030] Figure 2 This is a front view of the present invention;

[0031] Figure 3 This is a front sectional view of the present invention;

[0032] Figure 4 This is a schematic diagram of the adaptive compensation unit in this invention.

[0033] Reference numerals: 1. Substrate; 2. Source; 3. Drain; 4. MoS2 channel layer; 5. Gate; 6. Adaptive compensation unit; 61. Compensation electrode; 62. Feedback control circuit; 621. Resistance monitoring sensor; 622. Microprocessor; 63. Temperature sensor; 64. Temperature compensation module. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0035] Please see Figure 1 - Figure 4 This invention provides an adaptive contact resistance compensation MoS2 field-effect transistor structure, comprising:

[0036] A substrate 1, with a source electrode 2 and a drain electrode 3 respectively disposed on the top of the substrate 1;

[0037] MoS2 channel layer 4 is located between source 2 and drain 3, and source 2 and drain 3 form ohmic contact with MoS2 channel layer 4 for carrier transport.

[0038] The substrate 1 provides mechanical support and electrical insulation, the source 2 is used to input charge carriers, and the drain 3 is used to output charge carriers. The two form a conductive channel through the MoS2 channel layer 4, thereby realizing the regulation of current.

[0039] Gate 5 is disposed above the MoS2 channel layer 4 and isolated by the gate dielectric layer to control carrier flow. Gate 5 is made of polysilicon or metal material and isolated by silicon oxide or high-k dielectric layer to achieve efficient electric field control and low power consumption operation.

[0040] An adaptive compensation unit 6 is integrated near the source 2 and drain 3, and is electrically connected to the source 2 and drain 3. The adaptive compensation unit 6 incorporates a compensation electrode 61 and a feedback control circuit 62. The compensation electrode 61 is connected to the MoS2 channel layer 4 through an interface modification layer. The feedback control circuit 62 monitors and adjusts the bias voltage of the compensation electrode to achieve dynamic optimization of the contact resistance. The feedback control circuit 62 can sense the contact state between the source 2 and drain 3 and the MoS2 channel layer 4 in real time, and automatically adjusts the voltage applied to the compensation electrode based on the detected changes in the Schottky barrier height and interface state density. The effect of the bias voltage of the compensation electrode on the barrier height is the modulation of the energy band of the semiconductor surface or junction region by the electric field. A forward bias lowers the barrier height, promoting carrier injection; a reverse bias raises the barrier height, suppressing carrier injection. Precise control of the barrier height through the bias voltage enables current switching, amplification, or signal storage functions.

[0041] In this embodiment, preferably, the substrate 1 is made of high resistivity silicon or sapphire material to provide mechanical support and thermal stability; thereby effectively suppressing the thermal expansion effect and ensuring the long-term stability and reliability of the device in high-temperature environments.

[0042] In this embodiment, preferably, the source 2 and drain 3 adopt a titanium / gold multilayer metal structure to optimize carrier injection efficiency and interface adhesion, and further enhance ohmic contact efficiency.

[0043] In this embodiment, preferably, the compensation electrode 61 is made of a highly conductive metal material; this significantly reduces the electrode's own resistance loss, optimizes carrier injection efficiency, and ensures rapid response to resistance changes during the dynamic adjustment of the feedback control circuit 62, thereby improving the overall stability and reliability of the device. The highly conductive metal material can be selected from gold, copper, or silver, etc., to enhance interface conductivity and reduce thermal effects.

[0044] In this embodiment, preferably, the feedback control circuit 62 includes a resistance monitoring sensor 621 and a microprocessor 622. The resistance monitoring sensor 621 collects current-voltage characteristic data between the source 2 and the drain 3 in real time. The microprocessor 622 calculates the optimal bias voltage value based on a preset PID control algorithm and outputs it to the compensation electrode. This enables real-time response to resistance changes and precise adjustment of the bias voltage of the compensation electrode to dynamically maintain a low Schottky barrier and interface state density, thereby effectively reducing contact resistance fluctuations and improving the device's response speed, energy efficiency ratio, and long-term reliability.

[0045] In this embodiment, preferably, the preset PID control algorithm is based on the following function formula:

[0046]

[0047] In the formula, u(t) represents the bias voltage output of the compensation electrode 61;

[0048] e(t) represents the deviation signal between the real-time measured value of the contact resistance and the preset target value;

[0049] K p K i K d These are the proportional, integral, and differential gain coefficients, respectively.

[0050] In this embodiment, preferably, the microprocessor 622 dynamically generates the optimal bias voltage signal by calculating the function of the PID control algorithm in real time and applies it to the compensation electrode 61. Combined with the modulation effect of the interface modification layer on the band structure of the MoS2 channel layer 4, it effectively offsets the changes in contact resistance caused by environmental fluctuations or device aging, and maintains the stability of the ohmic contact at the source 2 and drain 3. Thus, it can maintain a stable output of contact resistance in real time under various environmental fluctuations or device aging conditions, significantly improving the overall performance and long-term reliability of the MoS2 field-effect transistor.

[0051] In this embodiment, preferably, the interface modification layer is made of ultrathin hafnium oxide or boron nitride material to enhance the interface stability between the MoS2 channel layer 4 and the compensation electrode 61; that is, it can effectively suppress the generation of interface defect states, reduce the carrier scattering probability, and thus optimize the charge injection efficiency between the compensation electrode 61 and the MoS2 channel layer 4; the highly stable interface structure ensures the accurate transmission and long-term reliability of the bias voltage signal and avoids the attenuation of compensation efficiency due to interface degradation.

[0052] In this embodiment, preferably, the adaptive compensation unit 6 further includes a temperature sensor 63 for monitoring changes in the working environment temperature; that is, it can acquire the working environment temperature data in real time and feed the data back to the microprocessor 622, so that the PID control algorithm can dynamically correct the bias voltage signal according to the temperature change; thereby more accurately compensating for the contact resistance drift caused by temperature fluctuations and avoiding the interference of thermal effects on the stability of ohmic contacts; at the same time, combined with the real-time monitoring of the temperature sensor 63, the adaptive compensation unit 6 can maintain the compensation accuracy under extreme temperature conditions, further improving the reliability and long-term stability of the device in a variable environment.

[0053] In this embodiment, preferably, the adaptive compensation unit 6 further includes a temperature compensation module 64, used to correct the influence of ambient temperature changes on contact resistance; that is, it can analyze the temperature data provided by the temperature sensor 63 in real time and dynamically generate a compensation factor according to a preset temperature-resistance model; thereby accurately quantifying the degree of influence of temperature on contact resistance and fine-tuning the parameter settings of the PID control algorithm accordingly; at the same time, the temperature compensation module 64 can work in conjunction with the microprocessor 622 to achieve closed-loop optimization of the compensation signal; thus effectively isolating thermal drift interference and ensuring the stability of the ohmic contact over a wide temperature range; in addition, combined with the synergistic effect of the interface modification layer and the compensation electrode 61, the temperature compensation module can significantly reduce temperature sensitivity and improve the long-term operational reliability of the device in extreme environments.

[0054] The above design effectively solves the performance bottlenecks mentioned in the background technology, such as limiting carrier injection efficiency and device mobility, causing a decrease in drive current, an increase in power consumption, and a slowdown in switching speed, as well as exacerbating the inconsistency of contact resistance and affecting large-scale integrated applications.

[0055] The adaptive contact resistance compensation mechanism of this invention significantly improves device performance in the following ways:

[0056] Improving carrier injection efficiency and mobility: Under the precise control of the feedback control circuit 62, the compensation electrode 61 applies an optimized bias voltage. Combined with the effective modulation of the band structure of the MoS2 channel layer 4 by the ultrathin interface modification layer (such as hafnium oxide or boron nitride), the Schottky barrier height and interface state density at the contact interface between the source 2 and drain 3 and the MoS2 channel layer 4 can be reduced. This allows carriers (electrons or holes) to be injected and extracted more efficiently, effectively overcoming the carrier injection bottleneck caused by Fermi level pinning in traditional MoS2 FETs.

[0057] Reduced power consumption and improved switching speed: The significant reduction in contact resistance directly decreases ohmic losses in the source-drain path, lowering the device's operating power consumption (both static and dynamic). Simultaneously, lower contact resistance and a more efficient carrier injection / extraction process shorten the time required for channel carrier concentration build-up and dissipation, effectively improving the device's switching speed. The PID algorithm implemented by the microprocessor 622 in the feedback control circuit 62 ensures the speed and accuracy of the compensation response, further optimizing dynamic performance.

[0058] Enhancing Contact Resistance Consistency and Large-Scale Integration Potential: The feedback control circuit 62 monitors the contact resistance status of each device in real time through the resistance monitoring sensor 621. The microprocessor 622 independently calculates and applies the optimal compensation voltage based on a preset PID algorithm. This closed-loop control mechanism can actively compensate for contact resistance changes caused by factors such as process fluctuations, material inhomogeneity, stress distribution differences, or local temperature gradients. With the cooperation of the temperature sensor 63 and the temperature compensation module 64, resistance drift caused by ambient temperature changes or self-heating effects is further corrected. This adaptive compensation capability ensures a high degree of consistency in contact resistance values ​​between different devices and under different operating conditions for the same device, greatly mitigating the impact of contact resistance inconsistency on device performance dispersion and laying a solid foundation for the reliable realization of large-scale, high-density integrated circuits.

[0059] Ensuring long-term stability and reliability: The interface modification layer effectively suppresses the generation of defect states and carrier scattering at the interface between the compensation electrode 61 and the MoS2 channel layer 4, ensuring the long-term stability of charge injection efficiency and compensation signal. The adaptive compensation unit 6 operates continuously, dynamically tracking and compensating for the gradual degradation of contact resistance caused by device aging (such as electromigration and interface degradation) or long-term slow changes in environmental conditions (such as slow temperature drift).

[0060] Working principle and usage process of this invention: When using this device,

[0061] First, a driving voltage is applied between the source 2 and the drain 3. Charge carriers (such as electrons or holes) are injected from the source 2, flow through the conductive channel formed by the MoS2 channel layer 4, and are finally output from the drain 3. The voltage applied to the gate 5 controls the switching or linear amplification of the channel current by regulating the charge carrier concentration in the MoS2 channel layer 4.

[0062] Meanwhile, the adaptive compensation unit 6 begins operation. The resistance monitoring sensor 621 monitors the current-voltage characteristics of the contact area between the source 2 and drain 3 and the MoS2 channel layer 4 in real time and calculates the real-time contact resistance value. This resistance data is transmitted to the microprocessor 622.

[0063] The microprocessor 622 compares the measured real-time contact resistance value with a preset target value (corresponding to an ideal low-resistance ohmic contact state), calculates the deviation signal e(t), and then uses a preset PID control algorithm function. Perform the calculation.

[0064] The calculated bias voltage signal u(t) is output and applied to the compensation electrode 61. The compensation electrode 61 is coupled to the MoS2 channel layer 4 through the interface modification layer (such as ultrathin hafnium oxide or boron nitride) below it. The application of this bias voltage can dynamically modulate the band structure of the MoS2 channel layer 4 in the source / drain contact region, effectively reducing the Schottky barrier height and interface state density.

[0065] In addition, temperature sensor 63 continuously monitors the operating ambient temperature of the device and transmits the temperature data to microprocessor 622 or a separate temperature compensation module 64. Microprocessor 622 or temperature compensation module 64 generates a temperature compensation factor based on a preset temperature-resistance model (e.g., an empirical formula or lookup table for contact resistance as a function of temperature). This compensation factor is used to dynamically correct the parameter settings of the PID control algorithm (e.g., adjusting K). p K i K d The weights of the bias voltage u(t) can be adjusted directly to precisely offset the contact resistance drift caused by temperature fluctuations.

[0066] Through the closed-loop feedback control process described above, the adaptive compensation unit 6 can dynamically sense and quickly respond to any changes in contact resistance (whether caused by environmental fluctuations, device aging, or temperature changes). By adjusting the bias voltage of the compensation electrode 61, it maintains a low-resistance, stable ohmic contact between the source 2 and drain 3 and the MoS2 channel layer 4 in real time, which greatly reduces the fluctuation of contact resistance and its impact on the channel current. This ensures that the entire MoS2 field-effect transistor device can maintain high response speed, excellent energy efficiency ratio, and long-term operational reliability under various operating conditions.

[0067] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A MoS2 field-effect transistor structure with adaptive contact resistance compensation, characterized in that, include: A substrate (1) having a source electrode (2) and a drain electrode (3) disposed on its upper surface; The MoS2 channel layer (4) is located between the source (2) and the drain (3), and the source (2) and the drain (3) form an ohmic contact with the MoS2 channel layer (4) for carrier transport. A gate (5) is disposed above the MoS2 channel layer (4) and isolated by a gate dielectric layer for controlling carrier flow; An adaptive compensation unit (6) is integrated near the source (2) and the drain (3). The adaptive compensation unit (6) has a built-in compensation electrode (61) and a feedback control circuit (62). The compensation electrode (61) is connected to the MoS2 channel layer (4) through an interface modification layer. The feedback control circuit (62) is used to monitor and adjust the bias voltage of the compensation electrode to achieve dynamic optimization of the contact resistance.

2. The MoS2 field-effect transistor structure with adaptive contact resistance compensation according to claim 1, characterized in that, The substrate (1) is made of high resistivity silicon or sapphire material to provide mechanical support and thermal stability.

3. The adaptive contact resistance compensation MoS2 field-effect transistor structure according to claim 1, characterized in that, The source (2) and drain (3) adopt a titanium / gold multilayer metal structure to optimize carrier injection efficiency and interface adhesion.

4. The MoS2 field-effect transistor structure with adaptive contact resistance compensation according to claim 1, characterized in that, The compensation electrode (61) is made of a highly conductive metallic material.

5. The MoS2 field-effect transistor structure with adaptive contact resistance compensation according to claim 1, characterized in that, The feedback control circuit (62) includes a resistance monitoring sensor (621) and a microprocessor (622). The resistance monitoring sensor (621) collects the current-voltage characteristic data between the source (2) and the drain (3) in real time. The microprocessor (622) calculates the optimal bias voltage value based on a preset PID control algorithm and outputs it to the compensation electrode.

6. The MoS2 field-effect transistor structure with adaptive contact resistance compensation according to claim 5, characterized in that, The preset PID control algorithm is based on the following function formula: In the formula, u(t) represents the bias voltage output of the compensation electrode (61); e(t) represents the deviation signal between the real-time measured value of the contact resistance and the preset target value; K p K i K d These are the proportional, integral, and differential gain coefficients, respectively.

7. The adaptive contact resistance compensation MoS2 field-effect transistor structure according to claim 5, characterized in that, The microprocessor (622) dynamically generates the optimal bias voltage signal by calculating the function of the PID control algorithm in real time and applies it to the compensation electrode (61). Combined with the modulation effect of the interface modification layer on the band structure of the MoS2 channel layer (4), it effectively offsets the change in contact resistance caused by environmental fluctuations or device aging, and maintains the stability of the ohmic contact at the source (2) and the drain (3).

8. The MoS2 field-effect transistor structure with adaptive contact resistance compensation according to claim 1, characterized in that, The interface modification layer is made of ultrathin hafnium oxide or boron nitride material and is used to enhance the interface stability between the MoS2 channel layer (4) and the compensation electrode (61).

9. The MoS2 field-effect transistor structure with adaptive contact resistance compensation according to claim 1, characterized in that, The adaptive compensation unit (6) also includes a temperature sensor (63) for monitoring changes in the working environment temperature.

10. The MoS2 field-effect transistor structure with adaptive contact resistance compensation according to claim 1, characterized in that, The adaptive compensation unit (6) also includes a temperature compensation module (64) for correcting the effect of ambient temperature changes on contact resistance.

Images