A method for constructing a total dose radiation effect model of a fin field-effect transistor

Abstract

This invention relates to a method for constructing a total dose radiation effect model for a FinFET, comprising the steps of constructing a FinFET with total dose radiation effect, constructing a parasitic transistor channel current equation, conducting a FinFET total dose radiation effect experiment, and extracting model parameters. The theoretical basis of this invention is that the total dose radiation effect generates oxide trap charges within the isolation oxide of the FinFET, reducing the parasitic transistor threshold and causing it to conduct prematurely, leading to an increase in the FinFET subthreshold current. Based on the physical mechanism of radiation damage, this invention proposes a parameter degradation equation. The parameters in the degradation equation have clear physical meanings, and the parameter adjustment range in model fitting is clear, making the model more convergent and achieving higher accuracy.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor device radiation resistance testing technology, specifically a method for constructing a total dose radiation effect model for a fin field-effect transistor. Background Technology

[0002] FinFET (Fin Field-Effect Transistor) is an innovative design derived from the standard planar field-effect transistor. In a planar transistor structure, the gate, which controls the current flow, only controls the on / off state of the circuit on one side of the gate. In a FinFET device, the gate is a forked, three-dimensional structure resembling a fish fin, allowing the on / off state of the circuit to be controlled from both sides of the gate. The FinFET structure significantly improves circuit control and reduces leakage, and also greatly shortens the gate length of the transistor, making it a mainstream technology for continuing Moore's Law. Currently, high-performance computing chips such as central processing units (CPUs) and graphics processing units (GPUs) widely adopt FinFET technology.

[0003] With the development of space missions such as deep space exploration, the amount of data acquired by spacecraft in orbit is increasing explosively, urgently requiring the use of high-performance computing chips to achieve intelligent processing of massive amounts of data. Radiation damage caused by high-energy particles in cosmic rays is a major threat to the safe and reliable application of integrated circuits in space. Radiation damage to integrated circuits is closely related to device fabrication technology. FinFETs, employing entirely new fabrication technologies, face new radiation effect problems. Total dose radiation effect is the permanent damage caused by the ionization of electronic devices by protons and electrons in cosmic rays. Electrons and holes generated by the ionization of protons and electrons in the device's insulating layer undergo recombination, separation, transport, and trapping processes to form trapped charges such as oxide charges and interface states, degrading the device's electrical performance.

[0004] Numerous studies have investigated the total dose radiation effect on FinFET devices, demonstrating that irradiation significantly increases the subthreshold current, leading to functional failure of FinFET integrated circuits. Gate-ring layout is a primary radiation hardening technique for planar devices; however, for FinFET devices, the three-dimensional channel structure is enclosed by the gate dielectric on both sides, making it impossible to form a gate-ring structure. Therefore, hardening measures specifically addressing the total dose effect on FinFET devices are currently lacking. Simulating the radiation damage characteristics of integrated circuits based on transistor radiation effect models and allowing for parameter degradation redundancy in FinFET device design is a feasible radiation hardening approach. However, there is currently no method for constructing a total dose radiation effect model for FinFET devices, and the parameter degradation equations are difficult to converge, necessitating further research into related technologies. Summary of the Invention

[0005] To overcome the shortcomings of the total dose radiation effect model of FinFET devices, where the degradation equation is difficult to converge, this invention proposes a method for constructing a total dose radiation effect model of FinFET field-effect transistors.

[0006] The technical solution adopted by this invention to solve its technical problem is:

[0007] A method for constructing a total dose radiation effect model for a finned field-effect transistor includes the following steps:

[0008] Step 1, Construction of the total dose radiation effect transistor:

[0009] The fin field-effect transistor includes a native transistor and a parasitic transistor; the parasitic transistor includes four ports: gate, drain, source, and substrate, which are shorted to the corresponding four ports of the native transistor: gate, drain, source, and substrate.

[0010] Step 2, Construction of parasitic transistor channel current equations

[0011] Parasitic transistor channel current ID para This represents the current flowing through the drain terminal D1 of the parasitic transistor. The parasitic transistor channel current ID is also mentioned. para The equation is as follows:

[0012]

[0013] In equation (1), W eff V is the effective width of the parasitic transistor. d1s1 For the drain-source voltage difference of the parasitic transistor, C ox For the gate oxide capacitance of the parasitic transistor, u eff L represents the carrier mobility in the parasitic transistor channel. eff V is the effective length of the transistor. g1s1teff For the effective gate voltage of the parasitic transistor, A bulk V is the volume charge factor. t For thermal voltage, V d1s1eff denoted as the effective drain-source voltage difference of the parasitic transistor, and a and b as fitting parameters.

[0014] Step 3: Conduct total dose radiation effect test

[0015] A total dose irradiation experiment was conducted using a gamma-ray irradiation device and a fin field-effect transistor to obtain the transfer characteristic curve.

[0016] Step 4, Model Parameter Extraction

[0017] Simulation calculations were performed, and the simulation results were compared with the transfer characteristic curves obtained in step 3.

[0018] Adjusting the parasitic transistor channel current ID in step 2 of constructing the parasitic transistor channel current equation para Relevant parameters: W eff C ox V g1s1teff a and / or b, to make the experimental results of the transfer characteristic curve consistent with the simulation results.

[0019] The model parameters W obtained are consistent with the experimental and simulation results. eff C ox V g1s1teff a, b.

[0020] In the above-mentioned method for constructing the total dose radiation effect model of fin field-effect transistors, X-ray irradiation devices can also be used in step 3 of the total dose radiation effect experiment.

[0021] In the above-described method for constructing the total dose radiation effect model of a finned field-effect transistor, in step 2 of the parasitic transistor channel current equation construction, the gate oxide capacitance C of the parasitic transistor... ox The calculation formula is as follows:

[0022]

[0023] In equation (2), ε ox t is the dielectric constant of the gate oxide of the parasitic transistor. ox The thickness of the gate oxide of the parasitic transistor.

[0024] Parasitic transistor gate effective voltage V g1s1teff The calculation formula is as follows:

[0025]

[0026] In equation (3), V th ε is the parasitic transistor threshold voltage. si Φ is the dielectric constant of the channel material. s V represents the surface potential of the parasitic transistor channel, q represents the electron charge, and V represents the surface potential. g1s1 For the gate-source voltage difference of the parasitic transistor, N ch The parasitic transistor channel doping concentration, n, V off These are the fitting parameters.

[0027] In the above-described method for constructing the total dose radiation effect model of a finned field-effect transistor, step 4, model parameter extraction, involves adjusting the parasitic transistor channel current ID in step 2, which was used in constructing the parasitic transistor channel current equation. para Relevant parameters: W eff t ox V th a, b, n, V offThis ensures that the experimental results of the transfer characteristic curve are consistent with the simulation results.

[0028] The model parameters W obtained are consistent with the experimental and simulation results. eff t ox V th a, b, n, V off .

[0029] In the above-described method for constructing a total dose radiation effect model for a fin field-effect transistor, in step 3 of the total dose radiation effect experiment, the fin field-effect transistor is an n-type fin field-effect transistor with a channel length of 86 nm and a drain-source voltage V0. ds The gate-source voltage V is 0.1V. gs The scan is performed in the range of 0 to 1.5V, with a scan step size of 0.02V.

[0030] In the above-mentioned method for constructing the total dose radiation effect model of fin field-effect transistors, the total irradiation dose in step 3, which involves conducting a total dose radiation effect experiment, is 300 klad (Si).

[0031] In the above-mentioned method for constructing the total dose radiation effect model of fin field-effect transistors, the total irradiation dose in step 3, which involves conducting a total dose radiation effect experiment, is 1000 krad (Si).

[0032] A fin field-effect transistor includes a native transistor and a parasitic transistor.

[0033] The parasitic transistor includes four ports: gate, drain, source, and substrate. The four ports of the parasitic transistor are shorted to the corresponding four ports of the native transistor.

[0034] The beneficial effects of this invention are:

[0035] A method for constructing a total dose radiation effect model for a FinFET is presented. Based on the physical mechanism of radiation damage, a parameter degradation equation is proposed. The parameters in the degradation equation have clear physical meanings, and the parameter adjustment range during model fitting is well-defined, leading to easier model convergence and higher accuracy. This invention achieves a total dose radiation effect model for a FinFET consistent with experimental results by adjusting only seven parameters. Attached Figure Description

[0036] Figure 1 A schematic diagram of the FinFET total dose radiation effect transistor;

[0037] Figure 2 The results of the transfer characteristic curve test of the FinFET device after irradiation with a dose of 300 klad (Si);

[0038] Figure 3 The results of the transfer characteristic curve test of the FinFET device after irradiation with a dose of 1000 klad (Si) are shown.

[0039] Figure 4 The figure shows a comparison between experimental and simulation results of the transfer characteristic curves of FinFET devices after irradiation with a dose of 300 klad (Si); the points in the figure represent the experimental results of the transfer characteristic curves, and the lines represent the simulation results of the transfer characteristic curves.

[0040] Figure 5 The figure shows a comparison between experimental and simulation results of the transfer characteristic curves of FinFET devices after irradiation with a dose of 1000 klad (Si). The points in the figure represent the experimental results of the transfer characteristic curves, and the lines represent the simulation results of the transfer characteristic curves. Detailed Implementation

[0041] Example 1

[0042] A method for constructing a total dose radiation effect model for a finned field-effect transistor includes the following steps:

[0043] Step 1, Construction of FinFET Total Dose Radiation Effect Transistor:

[0044] FinFETs consist of four ports: gate (G), drain (D), source (S), and substrate (B). Radiation-induced parameter degradation in FinFETs can be represented as a parasitic transistor, which also consists of four ports: gate (G1), drain (D1), source (S1), and substrate (B1). G1 and G, D1 and D, S1 and S, and B1 and B are shorted together. A schematic diagram of the FinFET total dose radiation effect transistor is shown below. Figure 1 As shown, when the fin field-effect transistor is not irradiated, the parasitic transistor is in the off state and does not affect the operation of the native transistor. However, after irradiation, the parasitic transistor turns on, affecting the operation of the native transistor. The simulation model using this structure is consistent with the physical mechanism of radiation damage, making it easier to obtain a convergent radiation effect model.

[0045] Step 2, Construction of the parasitic transistor channel current equation:

[0046] Parasitic transistor channel current ID para For the current flowing through terminal D1, ID para The equation is as follows:

[0047]

[0048] In equation (1), W eff L is the effective width of the parasitic transistor. eff V is the effective length of the transistor. d1s1 For the drain-source voltage difference of the parasitic transistor, Cox For the gate oxide capacitance of the parasitic transistor, u eff V represents the carrier mobility in the parasitic transistor channel. g1s1teff For the effective gate voltage of the parasitic transistor, A bulk V is the volume charge factor. t For thermal voltage, V d1s1eff denoted as the effective drain-source voltage difference of the parasitic transistor, and a and b as fitting parameters.

[0049] C ox The expression is as follows:

[0050]

[0051] In equation (2), ε ox t is the dielectric constant of the gate oxide of the parasitic transistor. ox The thickness of the gate oxide of the parasitic transistor.

[0052] V g1s1teff The expression is as follows:

[0053]

[0054] In equation (3), V th ε is the parasitic transistor threshold voltage. si Φ is the dielectric constant of the channel material. s For the parasitic transistor channel surface potential, V g1s1 The gate-source voltage difference of the parasitic transistor is q, where q is the electron charge and N is the source-gate voltage difference. ch The parasitic transistor channel doping concentration, n, V off These are the fitting parameters.

[0055] Step 3, Conduct FinFET total dose radiation effect test:

[0056] Total dose irradiation experiments were conducted on an n-type FinFET device with a channel length of 86 nm using a gamma-ray irradiation device. The transfer characteristic curves of the FinFET device after irradiation with doses of 300 klad(Si) and 1000 klad(Si) were measured. The test conditions for the transfer characteristic curves were: drain-source voltage V... ds =0.1V, gate-source voltage V gs The scan is performed in the range of 0-1.5V with a scan step size of 0.02V. Figure 2 The figure shows the experimental test results of the transfer characteristic curve of the FinFET device after irradiation with a dose of 300 klad (Si). Figure 3 The figure shows the experimental results of the transfer characteristic curve of the FinFET device after irradiation with a dose of 1000 klad (Si).

[0057] Step 4, Model Parameter Extraction:

[0058] In the SPICE simulator, construct the circuit schematic from step 1, simulate the transfer characteristic curve of the FinFET device, and compare it with the transfer characteristic curve of the irradiated FinFET device from step 3. Adjust the parameter W in the equation from step 2. eff t ox V th a, b, n, V off This continues until the simulation and experimental results match. Figure 4 The figure shows a comparison of experimental and simulation results of the transfer characteristic curves of a FinFET device after irradiation with a dose of 300 klad (Si), where parameter W... eff =5E-7m,t ox =2E-9m, V th =0.93V, a=0.000856, b=0.1, n=1, V off =0. Figure 5 The figure shows a comparison of experimental and simulation results of the transfer characteristic curves of a FinFET device after irradiation with a dose of 1000 klad (Si), where parameter W... eff =5E-7m,t ox =2E-9m, V th =0.2V, a=0.000856, b=0.1, n=1, V off =0.

[0059] like Figure 4 , 5 As shown, the FinFET total dose radiation effect model constructed in this embodiment is consistent with the experimental results.

Claims

1. A method for constructing a total dose radiation effect model for a finned field-effect transistor, characterized in that, Includes the following steps: Step 1, Construction of the total dose radiation effect transistor: The fin field-effect transistor includes a native transistor and a parasitic transistor; the parasitic transistor includes four ports: gate, drain, source, and substrate, which are shorted to the corresponding four ports of the native transistor: gate, drain, source, and substrate. Step 2, Construction of the parasitic transistor channel current equation: Parasitic transistor channel current ID para The current flowing through the drain D1 terminal of the parasitic transistor; the channel current ID of the parasitic transistor. para The equation is as follows: In equation (1), W eff V is the effective width of the parasitic transistor. d1s1 For the drain-source voltage difference of the parasitic transistor, C ox For the gate oxide capacitance of the parasitic transistor, u eff L represents the carrier mobility in the parasitic transistor channel. eff V is the effective length of the transistor. g1s1teff For the effective gate voltage of the parasitic transistor, A bulk V is the volume charge factor. t For thermal voltage, V d1s1eff The effective drain-source voltage difference of the parasitic transistor is denoted by , and a and b are fitting parameters. Step 3, Conduct a total dose radiation effect test: A total dose irradiation test was conducted on a fin field-effect transistor using a gamma-ray irradiation device or an X-ray irradiation device to obtain the transfer characteristic curve; Step 4, Model Parameter Extraction: Perform simulation calculations and compare the simulation results with the transfer characteristic curves obtained in step 3; Adjusting the parasitic transistor channel current ID in step 2 of constructing the parasitic transistor channel current equation para Relevant parameters: W eff C ox V g1s1teff a and / or b, to make the experimental results of the transfer characteristic curve consistent with the simulation results; The model parameters W obtained are consistent with the experimental and simulation results. eff C ox V g1s1teff a, b.

2. The method for constructing a total dose radiation effect model for a finned field-effect transistor according to claim 1, characterized in that, In step 2, when constructing the channel current equation for the parasitic transistor, the gate oxide capacitance C of the parasitic transistor... ox The calculation formula is as follows: In equation (2), ε ox t is the dielectric constant of the gate oxide of the parasitic transistor. ox The thickness of the gate oxide of the parasitic transistor; Parasitic transistor gate effective voltage V g1s1teff The calculation formula is as follows: In equation (3), V th ε is the parasitic transistor threshold voltage. si Φ is the dielectric constant of the channel material. s V represents the surface potential of the parasitic transistor channel, q represents the electron charge, and V represents the surface potential. g1s1 For the gate-source voltage difference of the parasitic transistor, N ch The parasitic transistor channel doping concentration, n, V off These are the fitting parameters.

3. The method for constructing a total dose radiation effect model for a finned field-effect transistor according to claim 1 or 2, characterized in that, In step 4, during model parameter extraction, the parasitic transistor channel current ID in step 2, which was used to construct the parasitic transistor channel current equation, is adjusted. para Relevant parameters: W eff t ox V th a, b, n, V off This ensures that the experimental results of the transfer characteristic curve are consistent with the simulation results; The model parameters W obtained are consistent with the experimental and simulation results. eff t ox V th a, b, n, V off .

4. The method for constructing a total dose radiation effect model for a finned field-effect transistor according to claim 1, characterized in that, In step 3, during the total dose radiation effect test, the fin field-effect transistor is an n-type fin field-effect transistor with a channel length of 86 nm and a drain-source voltage V. ds The gate-source voltage V is 0.1V. gs The scan is performed in the range of 0 to 1.5V, with a scan step size of 0.02V.

5. The method for constructing a total dose radiation effect model for a finned field-effect transistor according to claim 4, characterized in that, In step 3, the total dose radiation effect test is conducted, and the total irradiation dose is 300 krad (Si).

6. The method for constructing a total dose radiation effect model for a finned field-effect transistor according to claim 4, characterized in that, In step 3, the total dose radiation effect test is conducted, and the total irradiation dose is 1000 krad (Si).

7. A fin field-effect transistor for implementing the method for constructing a total dose radiation effect model of a fin field-effect transistor according to any one of claims 1-6, comprising a native transistor, characterized in that, It also includes parasitic transistors; The parasitic transistor includes four ports: gate, drain, source, and substrate. The four ports of the parasitic transistor are shorted to the corresponding four ports of the native transistor.

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