Two-dimensional material transistor Schmitt trigger circuit and implementation method thereof

Abstract

The invention relates to the field of semiconductors, and discloses a two-dimensional material transistor Schmitt trigger circuit and an implementation method thereof, and the two-dimensional material transistor Schmitt trigger circuit comprises a trigger main body part which controls the logic relation between an input signal and an output signal through a positive feedback mechanism, and achieves the hysteretic characteristic; and the booster circuit is used for increasing the voltage of a key node in the trigger main body part and enhancing the output driving capability. The implementation method comprises the following steps: when an input end signal is at a low level, the boosted circuit boosts the voltage at the gate end of the sixth transistor to the voltage of the boosted circuit to realize high-voltage driving; when the input end signal is at a high level, the boost circuit rapidly adjusts the voltage at the gate end of the sixth transistor to a low level. According to the invention, the blank that a two-dimensional material circuit does not have a full NMOS Schmitt trigger is filled, the excellent radiation resistance of a two-dimensional material transistor is fully utilized, and the reliability and stability of the circuit in a high-radiation environment are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a two-dimensional material transistor Schmitt trigger circuit and a method for implementing the same. Background Art

[0002] In recent years, two-dimensional material transistors (such as graphene and transition metal dichalcogenide MoS2) have gradually become a research hotspot for a new generation of semiconductor devices due to their excellent electrical properties and radiation resistance. Two-dimensional materials have high electron mobility, adjustable bandgap, atomic-scale ultra-thin structure, and exhibit a lower single-event upset rate and higher radiation resistance in a radiation environment. This enables transistors based on two-dimensional materials to perform excellently in high-radiation scenarios, especially suitable for aerospace, nuclear energy equipment, and extreme environment electronics fields. At the same time, two-dimensional material transistors also show great application potential in modern circuit design due to their low power consumption and high integration advantages.

[0003] Currently, due to problems such as poor uniformity in growing multi-layer materials for P-channel two-dimensional material transistors, inability to effectively reduce the Schottky barrier, and being easily affected by the Negative Bias Temperature Instability (NBTI) during long-term operation, two-dimensional material transistors mainly consist of N-channel transistors (NMOS); and there is no publicly available technology for a two-dimensional material circuit using an all-NMOS Schmitt trigger. Summary of the Invention

[0004] Aiming at the above problems, the purpose of the present invention is to provide a two-dimensional material transistor Schmitt trigger circuit and a method for implementing the same, which fill the gap in the two-dimensional material circuit without an all-NMOS Schmitt trigger, make full use of the excellent radiation resistance of two-dimensional material transistors, and significantly improve the reliability and stability of the circuit in a high-radiation environment.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions: A two-dimensional material transistor Schmitt trigger circuit, which includes: a trigger main body part that controls the logical relationship between input and output signals through a positive feedback mechanism and realizes a hysteresis characteristic; a boosting circuit for boosting the voltage of key nodes in the trigger main body part to enhance the output driving ability.

[0006] Furthermore, the trigger main body part includes a first transistor N1, a second transistor N2, a third transistor N3, and a sixth transistor N6; wherein, the first transistor N1, the second transistor N2, and the third transistor N3 form a voltage dividing network; The drain terminal of the first transistor N1 is connected in series with the source terminal of the second transistor N2, and the gate terminals of the second transistor N2 and the first transistor N1 are commonly connected to the input terminal IN. The source terminal of the first transistor N1 is connected to the ground GND, and the drain terminal of the second transistor N2 is connected to the output terminal OUT; The source terminal of the third transistor N3 is connected to the series connection point of the second transistor N2 and the first transistor N1, and the drain terminal of the third transistor N3 is connected to the power supply voltage VDD; The drain terminal of the sixth transistor N6 is connected to the power supply voltage VDD. The source terminal of the sixth transistor N6 is connected to the output terminal OUT and the gate terminal of the third transistor N3; The gate terminal of the sixth transistor N6 is connected to the boost structure as a key node.

[0007] Furthermore, the first transistor N1 and the third transistor N3 form a voltage divider to distribute the input signal at the input terminal IN to the source of the second transistor N2; The voltage division effect of the first transistor N1 and the third transistor N3 gradually reduces the source voltage of the second transistor N2, finally turning on the second transistor N2 and triggering positive feedback.

[0008] Furthermore, the first transistor N1, the second transistor N2, the third transistor N3, and the sixth transistor N6 are all two-dimensional material N-channel transistors.

[0009] Furthermore, the boost circuit includes a fourth transistor N4 and a fifth transistor N5; The source terminal of the fourth transistor N4 is connected to the ground GND. The drain terminal of the fourth transistor N4 is connected in series with the source terminal of the fifth transistor N5, and the gate terminal of the fourth transistor N4 is connected to the input terminal IN; The gate terminal of the fifth transistor N5 is connected to the series connection point of the fourth transistor N4 and the fifth transistor N5 and is connected to the gate terminal of the sixth transistor N6 in the trigger main body part; The drain terminal of the fifth transistor N5 is connected to the boost circuit voltage VDD1.

[0010] Furthermore, both the fourth transistor N4 and the fifth transistor N5 are two-dimensional material N-channel transistors.

[0011] Furthermore, the power supply voltage VDD1 of the boost circuit is higher than the power supply VDD of the trigger main body part.

[0012] A method for implementing a Schmitt trigger circuit based on the above two-dimensional material transistors includes: when the input signal at the input terminal IN is at a low level, the boost circuit raises the voltage at the gate terminal of the sixth transistor N6 to the boost circuit voltage VDD1 to achieve high-voltage drive; when the input signal at the input terminal IN is at a high level, the boost circuit quickly adjusts the voltage at the gate terminal of the sixth transistor N6 to a low level.

[0013] Further, when the level of the input terminal IN signal changes, the first transistor N1 and the second transistor N2 participate in conduction and cutoff. At the same time, the third transistor N3, which acts as a feedback transistor, functions as a source follower, and further follows the change of the output terminal OUT signal and feeds it back to the output terminal OUT signal, so that the logic of the overall circuit changes rapidly.

[0014] Further, when the input terminal IN signal jumps from a low level to a high level, due to the conduction characteristics of the first transistor N1 and the second transistor N2 and the action of the voltage dividing network, the input terminal IN signal needs to rise to be greater than 1 / 2 VDD to trigger positive feedback, which is the positive threshold voltage V2 of the Schmitt trigger. When the input terminal IN signal jumps from a high level to a low level, similarly due to the threshold voltage effect of the first transistor N1 and the second transistor N2 of the two-dimensional material, the input terminal IN signal must drop to be less than 1 / 2 VDD to trigger positive feedback, and a corresponding voltage is reached according to the set requirements for logic transition.

[0015] Due to the above technical solutions adopted by the present invention, it has the following advantages: 1. The Schmitt trigger circuit of the present invention adopts a two-dimensional material transistor based on all N-channel, filling the gap that there is no all-NMOS Schmitt trigger in the two-dimensional material circuit, and making full use of the excellent radiation resistance of the two-dimensional material transistor, thus significantly improving the reliability and stability of the circuit in a high-radiation environment.

[0016] 2. Compared with the traditional CMOS Schmitt trigger, due to the excellent radiation resistance and anti-NBTI ability of the two-dimensional material, the trigger circuit of the present invention reduces the logic state misflipping caused by radiation particles and the performance degradation affected by temperature.

[0017] 3. The present invention realizes the design of all-NMOS transistors, avoiding the problems of poor uniformity, relatively high Schottky barrier and NBTI effect degradation of two-dimensional PMOS transistors. Therefore, while reducing the design difficulty and material preparation difficulty of the circuit of the present invention, the radiation resistance and anti-NBTI ability are significantly improved.

[0018] 4. The technical solution adopted by the present invention provides a more robust and efficient solution for digital circuits applied in harsh environments, expanding the application potential of two-dimensional materials in high-performance electronic devices. Description of the Drawings

[0019] Figure 1 is a schematic structural diagram of an improved Schmitt trigger circuit based on a two-dimensional material all-N-channel transistor in an embodiment of the present invention; Figure 2 is a waveform diagram of circuit logic transition and hysteresis characteristics in an embodiment of the present invention. Detailed Embodiments

[0020] As the core of electronic products, integrated circuits play an important role in promoting the development of modern technology. Key devices such as memories have always been the iconic products for measuring the technical level of integrated circuits. With the continuous progress of integrated circuit design and manufacturing processes, the capacity, speed, and performance of various electronic devices have been greatly improved. However, with the rapid development of the aerospace industry and semiconductor technology, electronic devices are being widely used in high-radiation environments such as outer space and the nuclear industry. These extreme environments are filled with various radiation particles, such as high-energy electrons, protons, and neutrons. These radiation effects can trigger single-event effects, resulting in transistor performance degradation, logic state misflips, and even data transmission errors, seriously threatening the reliability of the circuit. Therefore, improving the radiation resistance of electronic circuits has become a key issue in integrated circuit design.

[0021] Therefore, the present invention proposes a Schmitt trigger circuit structure based on two-dimensional material transistors and its implementation method. This circuit structure combines the radiation resistance characteristics of two-dimensional materials, effectively enhancing the stability in a radiation environment. This circuit uses a fully NMOS structure, avoiding the problems of material uniformity and the inability to reduce the Schottky barrier during the PMOS fabrication process, and at the same time effectively resisting the negative bias temperature instability (NBTI) effect generated by PMOS. The circuit with a fully NMOS architecture not only avoids using PMOS transistors that are more difficult to fabricate but also effectively avoids the NBTI effect. It also has a simpler design, lower power consumption, and stronger radiation resistance. Therefore, implementing a two-dimensional material Schmitt trigger using a fully NMOS structure can not only reduce the design complexity but also significantly improve the radiation resistance and avoid the impact of single-event flips on the logic state.

[0022] Moreover, for the Schmitt trigger circuit proposed by the present invention, due to the high electron mobility and adjustable bandgap characteristics of two-dimensional material transistors, the positive feedback response of the circuit is faster, achieving good logic transitions and hysteresis characteristics. It shows application potential in data storage of digital circuits and working in extreme environments.

[0023] 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 of the embodiments of the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present invention fall within the scope of protection of the present invention.

[0024] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0025] In one embodiment of the present invention, a Schmitt trigger circuit for a two-dimensional material transistor is provided, which is a Schmitt trigger circuit with a structural improvement based on a two-dimensional material circuit. In this embodiment, as Figure 1 shown, the circuit includes: A trigger main body part that controls the logical relationship between input and output signals through a positive feedback mechanism and realizes a hysteresis characteristic; A boost circuit for boosting the voltage of key nodes in the trigger main body part and enhancing the output driving ability.

[0026] When the present invention is used, by combining the boost circuit and the feedback mechanism in the trigger main body part, the hysteresis characteristic of the input signal and a stable output logic transition are achieved.

[0027] In this embodiment, the trigger main body part includes a first transistor N1, a second transistor N2, a third transistor N3, and a sixth transistor N6; among them, the first transistor N1, the second transistor N2, and the third transistor N3 form a voltage dividing network. Specifically: The drain terminal of the first transistor N1 is connected in series with the source terminal of the second transistor N2, and the gate terminals of the second transistor N2 and the first transistor N1 are commonly connected to the input terminal IN. The source terminal of the first transistor N1 is connected to the ground GND, and the drain terminal of the second transistor N2 is connected to the output terminal OUT; The source terminal of the third transistor N3 is connected to the series connection point of the second transistor N2 and the first transistor N1, and the drain terminal of the third transistor N3 is connected to the power supply voltage VDD; The drain terminal of the sixth transistor N6 is connected to the power supply voltage VDD, and the source terminal of the sixth transistor N6 is connected to the output terminal OUT and the gate terminal of the third transistor N3; the gate terminal of the sixth transistor N6 is connected to the boost structure as a key node.

[0028] Among them, the first transistor N1 and the third transistor N3 form a voltage divider to distribute the input terminal IN signal to the source electrode of the second transistor N2; the voltage dividing effect of the first transistor N1 and the third transistor N3 gradually reduces the source voltage of the second transistor N2, and finally turns on the second transistor N2 to trigger positive feedback.

[0029] In this embodiment, the boost circuit includes a fourth transistor N4 and a fifth transistor N5.

[0030] The source terminal of the fourth transistor N4 is connected to the ground GND. The drain terminal of the fourth transistor N4 is in series with the source terminal of the fifth transistor N5. The gate terminal of the fourth transistor N4 is commonly connected to the input terminal IN, and the gate terminals of the second transistor N2 and the first transistor N1. The gate terminal of the fifth transistor N5 is connected to the series connection point of the fourth transistor N4 and the fifth transistor N5, and is connected to the gate terminal of the sixth transistor N6. The drain terminal of the fifth transistor N5 is connected to the boost circuit voltage VDD1.

[0031] In the above embodiments, the first transistor N1, the second transistor N2, the third transistor N3, the fourth transistor N4, the fifth transistor N5, and the sixth transistor N6 are all two-dimensional material N-channel transistors, all simply referred to as transistors. Since the circuit structure of the present invention is implemented by two-dimensional materials, the circuit has radiation resistance and NBTI resistance; at the same time, due to the adjustable bandgap characteristics of two-dimensional material transistors, the circuit has a hysteresis width that can be flexibly adjusted.

[0032] In the above embodiments, the boost circuit composed of two-dimensional material N-channel transistors N4 and N5 has a principle similar to that of an inverter. The power supply voltage VDD1 of the boost circuit is higher than the power supply VDD of the main body of the flip-flop. This independent power supply design ensures that the voltage at the gate terminal of the sixth transistor N6 can be higher than the maximum voltage of the main body of the flip-flop, and through the fourth transistor N4 and the fifth transistor N5, the voltage of the intermediate node is increased by using their natural conduction characteristics, enhancing the conduction ability of the sixth transistor N6.

[0033] In the above embodiments, for the main body of the Schmitt trigger adopted in the present invention, due to the high electron mobility and adjustable bandgap characteristics of two-dimensional material transistors, the positive feedback response is more rapid, realizing good logic transitions and hysteresis characteristics.

[0034] In an embodiment of the present invention, a method for implementing a two-dimensional material transistor Schmitt trigger circuit is provided, which works based on the two-dimensional material transistor Schmitt trigger circuit in the above embodiments. In this embodiment, as Figure 1 shown, the method includes: 1) Voltage regulation: When the input terminal IN signal is at a low level, the boost circuit raises the voltage at the gate terminal of the sixth transistor N6 to VDD1 to achieve high-voltage drive. When the input terminal IN signal is at a high level, the boost circuit quickly adjusts the voltage at the gate terminal of the sixth transistor N6 to a low level.

[0035] In this embodiment, due to the introduction of the boost circuit, not only the problem of insufficient output dynamic range of the traditional NMOS Schmitt trigger is overcome, but also the NBTI effect of the PMOS is effectively reduced.

[0036] 2) Feedback: The positive feedback is mainly dominated by the third transistor N3 as the feedback transistor, and the second transistor N2 plays an auxiliary role. When the input signal IN undergoes a level conversion, not only the first transistor N1 and the second transistor N2 are involved in conduction and cutoff, but also since the feedback transistor N3 acts as a source follower (the gate terminal of N3 is the input, the drain terminal is the output, and the source terminal is the power supply voltage VDD), a further follow-up conversion is performed by the conversion of the output signal OUT, and then fed back to the output signal OUT, making the logic transition of the overall circuit faster.

[0037] 3) The hysteresis characteristic of the circuit is as Figure 2 shown, mainly controlled by the voltage division network composed of the first transistor N1, the second transistor N2, and the third transistor N3, as well as the threshold voltages of the first transistor N1 and the second transistor N2. Due to the adjustable bandgap characteristic of the two-dimensional material, the second transistor N2 that controls the hysteresis interval can exhibit a more flexible hysteresis width (the hysteresis width here is 1V). When the input signal IN jumps from a low level to a high level, due to the conduction characteristics of the first transistor N1 and the second transistor N2 and the effect of the voltage division network, the input signal IN must rise to be greater than 1 / 2 VDD to trigger positive feedback, which is the positive threshold voltage V2 of the Schmitt trigger; when the input signal IN jumps from a high level to a low level, similarly due to the threshold voltages (Vth) of the first transistor N1 and the second transistor N2 of the two-dimensional material, the input signal IN must drop to be less than 1 / 2 VDD to trigger positive feedback, and can reach the corresponding voltage for logic transition according to the set requirements.

[0038] Embodiment, as Figure 1 shown, when the input signal IN jumps from a low level to a high level, at the beginning, the boost circuit (N4 and N5) outputs a high level to the gate terminal of the sixth transistor N6, and the conduction of the sixth transistor N6 makes the output signal OUT at a high level. When the input signal IN gradually becomes higher, the conduction ability of the sixth transistor N6 gradually decreases, and the output signal OUT starts to drop. At the same time, the first transistor N1 starts to conduct, and the change in the drain voltage drop of the first transistor N1 causes the second transistor N2 to start to conduct, accelerating the pulling down of the output signal OUT. As the output signal OUT decreases, the conduction ability of the feedback transistor N3 decreases, further reducing the pull-up current, making the output signal OUT drop more rapidly.

[0039] When the signal at the input terminal IN jumps from high level to low level, at the beginning stage, the boost circuit (N4 and N5) outputs a low level to the gate terminal of the sixth transistor N6. The cut-off of the sixth transistor N6 makes the signal at the output terminal OUT low. When the signal at the input terminal IN gradually becomes lower, the conduction ability of the sixth transistor N6 gradually increases, and the signal at the output terminal OUT gradually increases. At the same time, the conduction abilities of the first transistor N1 and the second transistor N2 decrease. The first transistor N1 functions to pull down the source voltage of the second transistor N2 when the signal at the input terminal IN is at high level. As the signal at the input terminal IN decreases, the pulling-down ability of the first transistor N1 is insufficient, further weakening the conduction ability of the second transistor N2. Since the first transistor N1 and the second transistor N2 cannot further pull down the signal at the output terminal OUT, the signal at the output terminal OUT further increases, causing the feedback transistor N3 to conduct, providing an additional pull-up current and further accelerating the increase of the signal at the output terminal OUT.

[0040] In summary, the Schmitt trigger circuit of the present invention uses all-N-channel two-dimensional material transistors, filling the gap that there is no all-NMOS Schmitt trigger in two-dimensional material circuits, and making full use of the excellent radiation resistance of two-dimensional material transistors, thus significantly improving the reliability and stability of the circuit in a high-radiation environment. Compared with traditional CMOS Schmitt triggers, due to the excellent radiation resistance and anti-NBTI ability of two-dimensional materials, the trigger circuit of the present invention reduces the logic state misflips caused by radiation particles and the performance degradation affected by temperature. This technical solution provides a more robust and efficient solution for digital circuits applied in harsh environments, expanding the application potential of two-dimensional materials in high-performance electronic devices.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features. However, such modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A Schmitt trigger circuit for a two-dimensional material transistor, characterized in that Comprising: A trigger main body part that controls the logical relationship between input and output signals through a positive feedback mechanism and realizes a hysteresis characteristic; A boost circuit for boosting the voltage of a key node in the trigger main body part to enhance the output driving ability.

2. The two-dimensional material transistor Schmitt trigger circuit according to claim 1, characterized in that The trigger main body part includes a first transistor N1, a second transistor N2, a third transistor N3, and a sixth transistor N6; among them, the first transistor N1, the second transistor N2, and the third transistor N3 form a voltage dividing network; The drain terminal of the first transistor N1 is connected in series with the source terminal of the second transistor N2, and the gate terminals of the second transistor N2 and the first transistor N1 are commonly connected to the input terminal IN, the source terminal of the first transistor N1 is connected to the ground GND, and the drain terminal of the second transistor N2 is connected to the output terminal OUT; The source terminal of the third transistor N3 is connected to the series connection point of the second transistor N2 and the first transistor N1, and the drain terminal of the third transistor N3 is connected to the power supply voltage VDD; The drain terminal of the sixth transistor N6 is connected to the power supply voltage VDD, the source terminal of the sixth transistor N6 is connected to the output terminal OUT and the gate terminal of the third transistor N3; the gate terminal of the sixth transistor N6 is connected to the boost structure as a key node.

3. The two-dimensional material transistor Schmitt trigger circuit according to claim 2, wherein, The first transistor N1 and the third transistor N3 form a voltage divider to distribute the input terminal IN signal to the source electrode of the second transistor N2; the voltage dividing effect of the first transistor N1 and the third transistor N3 gradually reduces the source electrode voltage of the second transistor N2, and finally turns on the second transistor N2 to trigger positive feedback.

4. The two-dimensional material transistor Schmitt trigger circuit according to claim 2, wherein The first transistor N1, the second transistor N2, the third transistor N3, and the sixth transistor N6 are all two-dimensional material N-channel transistors.

5. The two-dimensional material transistor Schmitt trigger circuit according to claim 1, wherein The boost circuit includes a fourth transistor N4 and a fifth transistor N5; The source terminal of the fourth transistor N4 is connected to the ground GND, the drain terminal of the fourth transistor N4 is connected in series with the source terminal of the fifth transistor N5, and the gate terminal of the fourth transistor N4 is connected to the input terminal IN; The gate terminal of the fifth transistor N5 is connected to the series connection point of the fourth transistor N4 and the fifth transistor N5 and is connected to the gate terminal of the sixth transistor N6 in the trigger main body part; the drain terminal of the fifth transistor N5 is connected to the boost circuit voltage VDD1.

6. The two-dimensional material transistor Schmitt trigger circuit according to claim 5, characterized in that The fourth transistor N4 and the fifth transistor N5 are all two-dimensional material N-channel transistors.

7. The two-dimensional material transistor Schmitt trigger circuit according to claim 5, wherein The power supply voltage VDD1 of the boost circuit is higher than the power supply VDD of the trigger main body part.

8. A method for implementing a Schmitt trigger circuit of a two-dimensional material transistor according to any one of claims 1 to 7, characterized in that, Comprising: When the input terminal IN signal is at a low level, the boost circuit boosts the voltage at the gate terminal of the sixth transistor N6 to the boost circuit voltage VDD1 to achieve high-voltage driving; when the input terminal IN signal is at a high level, the boost circuit quickly adjusts the voltage at the gate terminal of the sixth transistor N6 to a low level.

9. The implementation method according to claim 8, wherein Comprising: When the input terminal IN signal undergoes a level transformation, the first transistor N1 and the second transistor N2 participate in conduction and cutoff, and at the same time, the third transistor N3 as a feedback transistor acts as a source follower, and the transformation of the output terminal OUT signal is further followed and transformed, and then fed back to the output terminal OUT signal to cause the logic of the overall circuit to quickly jump.

10. The implementation method according to claim 8, wherein Comprising: When the input signal at IN jumps from a low level to a high level, due to the conduction characteristics of the first transistor N1 and the second transistor N2 and the function of the voltage dividing network, the input signal at IN needs to rise to be greater than 1 / 2 VDD to trigger positive feedback, which is the positive threshold voltage V2 of the Schmitt trigger; when the input signal at IN jumps from a high level to a low level, similarly due to the threshold voltage effects of the first transistor N1 and the second transistor N2 made of two-dimensional materials, the input signal at IN must drop to be less than 1 / 2 VDD to trigger positive feedback, and a corresponding voltage is reached for logical transition according to the set requirements.

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