A transient dose rate radiation effect TCAD model calibration method and system

Abstract

The application discloses a kind of transient dose rate radiation effect TCAD model calibration method and system, the method steps include: step S1: the initial TCAD model of transistor is constructed;Step S2: extracting the electrical characteristic parameter under standard model;Step S3: the parameter in model is adjusted in turn, the linear region transfer characteristic curve of transistor is simulated;Step S4: the saturation region transfer characteristic curve of transistor is simulated, and the source / drain contact resistance parameter in model is adjusted;Step S5: the output characteristic curve of transistor is simulated, and the saturation velocity and high field mobility degradation parameter in model are adjusted;Step S6: according to calibration model information, simulation is carried out, and the distribution data and concentration of electron hole pair are obtained;Step S7: the connection mode of transistor is adjusted in model parameter, to simulate the process that transient radiation acts on the transistor without applying bias voltage.The application has the advantages of simple implementation method, low cost, calibration precision and efficiency etc..

Description

Technical Field

[0001] This invention relates to the field of semiconductor device radiation effect simulation technology, and in particular to a method and system for calibrating a TCAD (Technology Computer-Aided Design) model of instantaneous dose rate radiation effect. Background Technology

[0002] Instantaneous high-dose-rate radiation, such as strong gamma-ray pulses, can generate a large number of photogenerated electron-hole pairs and form photocurrent pulses in CMOS (Complementary Metal Oxide Semiconductor) integrated circuits, leading to functional errors or even permanent failures in the integrated circuit chip. This is known as the instantaneous dose-rate radiation effect. When designing integrated circuits resistant to instantaneous dose-rate radiation effects, accurate simulation of these effects is necessary to analyze their response under such conditions.

[0003] In existing technologies, TCAD tools are typically used to perform device-level or circuit unit-level physical simulations of CMOS integrated circuits. However, constructing a TCAD model that can accurately reflect the conventional electrical characteristics of the device and precisely simulate the radiation response presents the following problems: (1) TCAD models contain numerous physical parameters (such as doping, mobility, contact resistance, etc.), which makes parameter calibration of TCAD models difficult. Moreover, existing calibration methods usually rely on experience and repeated iterations, resulting in low calibration efficiency and accuracy.

[0004] (2) When simulating dose rate effects, it is necessary to accurately describe the spatiotemporal distribution of electron-hole pairs generated by radiation inside the device. Existing methods usually use uniform or simplified generation models. Such methods cannot reflect the complex three-dimensional non-uniformity of the real radiation environment and energy deposition, resulting in significant deviations between the simulation results and the actual physical process. Summary of the Invention

[0005] The technical problem to be solved by this invention is as follows: In view of the above-mentioned problems existing in the prior art, this invention provides a method and system for calibrating the instantaneous dose rate radiation effect TCAD model that is simple to implement, low in cost, and has high calibration accuracy and efficiency. It can efficiently and accurately calibrate the basic parameters of the TCAD model, and at the same time, it can accurately calibrate the distribution of electron-hole pairs generated by radiation in the TCAD, thereby providing an accurate TCAD model for the simulation of instantaneous dose rate radiation effect, and improving the efficiency of TCAD modeling and simulation accuracy.

[0006] To solve the above-mentioned technical problems, the technical solution proposed by this invention is as follows: A method for calibrating a TCAD model of instantaneous dose rate radiation effects, comprising the following steps: Step S1: Construct the initial TCAD model of the transistor in the TCAD environment; Step S2: Simulate the linear region transfer characteristic curve Id00 of the transistor under low drain-source voltage using the standard model, and extract the electrical characteristic parameters under the standard model. The electrical characteristic parameters include the threshold voltage, the current in the subthreshold swing region, and the transconductance and current curves in the strong inversion region. Step S3: Sequentially adjust the channel doping concentration distribution, gate work function parameter, and carrier mobility parameter in the TCAD model of the transistor. After each adjustment, use the TCAD model to simulate the linear region transfer characteristic curve of the transistor under low drain-source voltage and extract the electrical characteristic parameters respectively until the error between the final adjusted electrical characteristic parameters and the electrical characteristic parameters under the standard model is less than a preset threshold. Step S4: Simulate the first saturation region transfer characteristic curve Id20 of the transistor using the standard model at the rated drain-source operating voltage, adjust the source / drain contact resistance parameters in the transistor TCAD model, and simulate the second saturation region transfer characteristic curve Id30 of the transistor using the TCAD model at the rated drain-source operating voltage until the error between the first saturation region transfer characteristic curve Id20 and the second saturation region transfer characteristic curve Id30 is less than the preset threshold. Step S5: Simulate the first output characteristic curve Id0 of the transistor under rated gate voltage using the standard model, and extract the first saturation current Isat0 and the first output resistance R0. Adjust the saturation velocity and high field mobility degradation parameters in the transistor's TCAD model, and simulate the second output characteristic curve Id1 of the transistor under rated gate voltage using the TCAD model. Extract the second saturation current Isat1 and the second output resistance R1 until the parameter error between the second saturation current Isat1 and the second output resistance R1 and the first saturation current Isat0 and the first output resistance R0 is less than a preset threshold. Step S6: Perform simulation based on the TCAD model information obtained from the current calibration to obtain the distribution data of electron-hole pairs and the concentration of electron-hole pairs in the transistor after radiation; Step S7: Adjust the parameters describing the instantaneous dose rate radiation effect in the TCAD model obtained by the current calibration to simulate the process of instantaneous radiation acting on a transistor without applied bias voltage, obtain the distribution data of electron-hole pairs and the concentration of electron-hole pairs in the transistor when the dose rate of the radiation pulse is at its peak, until the error between the distribution data of electron-hole pairs and the concentration of electron-hole pairs obtained in step S6 is less than a preset threshold, and obtain the final calibrated TCAD model.

[0007] Further, step S1 includes: extracting a standard SPICE model from the process design kit (PDK), reading the defined device structure parameters and basic physical parameters, and constructing an initial TCAD model of the NMOS transistor in the TCAD environment. The device structure parameters include gate length, gate oxide thickness, and junction depth.

[0008] Furthermore, the subthreshold swing region is the region that satisfies 0≤|Vg|≤|Vth0|, and the strong inversion region is the region that satisfies |Vth0|≤|Vg|≤VDD.

[0009] Further, in step S2, the extracted electrical characteristic parameters under the standard model include the first threshold voltage Vth0, the first current curve Id01 in the subthreshold swing region, and the first transconductance Gm0 and the first current curve Id02 in the strong inversion region; step S3 includes: Step S301: Adjust the channel doping concentration distribution and gate work function parameters in the current TCAD model, and use the current TCAD model to simulate the linear region transfer characteristic curve Id10 of the transistor under low drain-source voltage. Extract the second threshold voltage Vth1 and the second current curve Id11 of the subthreshold swing region, so that the parameter error e1 between the second threshold voltage Vth1 and the first threshold voltage Vth0 is less than the first preset threshold A, and the curve error e2 between the second current curve Id11 of the subthreshold swing region and the first current curve Id01 is less than the first preset threshold A. Step S302: Adjust the carrier mobility parameters in the transistor TCAD model, and re-simulate the linear region transfer characteristic curve Id10 of the transistor under low drain-source voltage using the TCAD model. Extract the second transconductance Gm1 and the second current curve Id12 of the strong inversion region, so that the parameter error e3 between the second transconductance Gm1 and the first transconductance Gm0 in the strong inversion region is less than the first preset threshold A, and the curve error e4 between the second current curve Id12 and the first current curve Id02 in the strong inversion region is less than the first preset threshold A. Step S303. If the curve errors e1 and e3 and the parameter errors e2 and e4 are all less than the first preset threshold A, then proceed to step S4.

[0010] Further, in step S4, the source / drain contact resistance parameters in the transistor TCAD model are adjusted until the curve error e5 between the second saturation region transfer characteristic curve Id30 and the first saturation region transfer characteristic curve Id20 is less than the first preset threshold A; in step S5, the saturation velocity and high field mobility degradation parameters in the transistor TCAD model are adjusted until the parameter error e6 between the second saturation current Isat1 and the first saturation current Isat0 is less than the first preset threshold A, and the parameter error e7 between the second output resistance R1 and the first output resistance R0 is less than the first preset threshold A.

[0011] Further, step S6 includes: importing the TCAD model information obtained from the current calibration into Geant4, a nuclear physics simulation tool based on the Monte Carlo method, to simulate the process of instantaneous radiation acting on the transistor. During the simulation, the transport of all primary and secondary particles is tracked to obtain the distribution data of electron-hole pairs in the transistor after radiation and to extract the first electron-hole pair concentration. The first electron-hole pair concentration includes the electron-hole pair concentration n00 at the center of the drain region, the electron-hole pair concentration n01 at the center of the channel, the electron-hole pair concentration n02 at the center of the well, and the electron-hole pair concentration n03 at the center of the substrate.

[0012] Further, step S7 includes: adjusting the parameters DoseRate (dose rate), DoseTime (irradiation time), DoseTSigma (irradiation time standard deviation), and g0 (electron-hole pair generation rate) in the TCAD model obtained by the current calibration, and short-circuiting the source, drain, gate, and well contacts of the transistor to simulate the process of instantaneous radiation acting on a transistor without applied bias voltage, obtaining the distribution data of electron-hole pairs in the transistor when the dose rate of the radiation pulse is at its peak, and extracting the second electron-hole pair concentration. The second electron-hole pair concentration includes the electron-hole pair concentration n10 at the center of the drain region, the electron-hole pair concentration n11 at the center of the channel, the electron-hole pair concentration n12 at the center of the well, and the electron-hole pair concentration n13 at the center of the substrate, so that the parameter error between the second electron-hole pair concentration and the first electron-hole pair concentration is less than the second preset threshold B.

[0013] Furthermore, step S7 also includes shorting the source, drain, gate, and well contacts of the transistor in the TCAD model to maintain consistency with the simulation conditions in step S6.

[0014] A TCAD model calibration system includes a processor and a memory, the memory for storing a computer program and the processor for executing the computer program to perform the method described above.

[0015] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described above.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention calibrates model parameters step by step according to the electrical characteristics of the device, which not only makes the parameters easier to calibrate and the curves easier to fit, but also ensures the convergence of TCAD model simulation, thereby greatly improving TCAD modeling efficiency and simulation accuracy.

[0017] 2. This invention, by extracting the distribution of electron-hole pairs generated by dose rate radiation effect based on high-precision simulation results after stepwise calibration of TCAD model parameters, can not only achieve reliable calibration of TCAD model, but also significantly improve the accuracy of TCAD simulation of instantaneous dose rate radiation effect. Attached Figure Description

[0018] Figure 1 This is a schematic diagram illustrating the implementation process of the instantaneous dose rate radiation effect TCAD model calibration method in this embodiment.

[0019] Figure 2 This is a schematic diagram illustrating the complete process of calibrating the TCAD model for instantaneous dose rate radiation effects in a specific application embodiment of the present invention. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention.

[0021] As disclosed in this invention, unless the context clearly indicates otherwise, words such as "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. The terms "first," "second," and similar terms used in this invention disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, words such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connected" or "linked" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0022] The core idea of ​​this invention is based on the fact that different changes in model parameters result in different values ​​of electrical curves at different curve positions. By calibrating the model parameters step by step according to the electrical characteristics of the device, and simultaneously extracting the distribution of electron-hole pairs generated by the dose rate radiation effect, the process of instantaneous radiation acting on a transistor without applied bias voltage is simulated, which enables efficient TCAD model calibration and simulation of instantaneous dose rate radiation effects.

[0023] Considering that the electrical response under non-radiative conditions is independent of radiation-related parameters, while the electrical response under radiative conditions is correlated with both radiation-independent and radiation-related parameters, calibrating radiation-related parameters when radiation-independent model parameters are inaccurate, followed by calibrating radiation-independent model parameters, will alter the electrical response under radiative conditions. This necessitates recalibrating radiation-related parameters and refitting the radiative electrical response. However, if radiation-independent model parameters are calibrated first, followed by radiation-related parameters, the radiation-related parameters do not affect the non-radiative electrical response, eliminating the need for recalibration of radiation-independent parameters. Therefore, this invention, by first calibrating the radiation-independent model parameters of the transistor and then calibrating the radiation-related parameters, significantly improves calibration efficiency.

[0024] Meanwhile, considering the varying degrees of importance of different parameters: the channel doping concentration distribution and gate work function parameter are most closely related to the subdomain of the transistor's linear transfer characteristic curve. Changes in these parameters can lead to drastic changes in the subdomain of the linear transfer characteristic curve, as well as significant changes in the strong inversion region of the linear transfer characteristic curve. They also affect the saturation transfer characteristic curve and the output characteristic curve, requiring priority calibration. Changes in the carrier mobility parameter can cause drastic changes in the strong inversion region of the linear transfer characteristic curve, significantly impacting the subdomain and also affecting the saturation transfer characteristic curve and the output characteristic curve. Therefore, iterative approximation with the channel doping concentration distribution and gate work function parameter is necessary. The source / drain contact resistance parameter mainly affects the saturation transfer characteristic curve and the output characteristic curve, with a weak impact on the transfer characteristic curve under low drain-source voltage. The saturation velocity and high-field mobility degradation parameter mainly affect the output characteristic curve describing high electric field characteristics, with a weak impact on the transfer characteristic curve. Therefore, this invention calibrates the TCAD model in the following order: first, the channel doping concentration distribution and gate work function parameters are calibrated; then, the carrier mobility parameters and source / drain contact resistance parameters are calibrated; and finally, the saturation velocity and high-field mobility degradation parameters are calibrated. This allows for step-by-step calibration of the TCAD model parameters, taking into full account the characteristics and importance of different parameters. This not only makes the parameters easier to calibrate and the curves easier to fit, but also ensures the convergence of the TCAD model simulation, thereby significantly improving the efficiency of TCAD modeling and the accuracy of simulation.

[0025] Based on the step-by-step calibration of TCAD model parameters, this invention extracts the distribution of electron-hole pairs generated by dose rate radiation effects. This not only enables reliable calibration of the TCAD model but also allows for accurate calibration of the electron-hole pair distribution generated by radiation in the TCAD, significantly improving the accuracy of TCAD simulation of instantaneous dose rate radiation effects.

[0026] like Figure 1 As shown, the steps of the instantaneous dose rate radiation effect TCAD model calibration method in this embodiment include: Step S1: Construct the initial TCAD model of the transistor in the TCAD environment.

[0027] Specifically, a standard SPICE model can be extracted from the process design kit (PDK), the defined device structure parameters and basic physical parameters can be read, and an initial TCAD model of the NMOS transistor can be built in the TCAD environment. The device structure parameters include gate length, gate oxide thickness, junction depth, etc.

[0028] Step S2: Simulate the linear region transfer characteristic curve Id00 of the transistor under low drain-source voltage using the standard model, and extract the electrical characteristic parameters under the standard model. The electrical characteristic parameters include the threshold voltage, the current in the subthreshold swing region, and the transconductance and current curves in the strong inversion region.

[0029] In this embodiment, the standard model can specifically be the standard SPICE model.

[0030] In this embodiment, the subthreshold swing region can be defined as the region that satisfies 0≤|Vg|≤|Vth0|, that is, the voltage value |Vg| is in the range of [0, |Vth0|], and the strong inversion region is defined as the region that |Vth0|≤|Vg|≤VDD, that is, the voltage value |Vg| is in [|Vth0|,VDD], where VDD is the operating power supply voltage.

[0031] Specifically, the standard SPICE model can be used to measure the drain-source voltage V. ds The linear region transfer characteristic curve Id00(Vg) of the simulated NMOS transistor at 0.05V is used to extract the threshold voltage Vth0 and the subthreshold swing region from the linear region transfer characteristic curve Id0. The current Id01(Vg) of the strong inversion region ( The transconductance Gm0(Vg) and current curve Id02(Vg) are shown.

[0032] Step S3: Sequentially adjust the channel doping concentration distribution, gate work function parameter, and carrier mobility parameter in the TCAD model of the transistor. After each adjustment, use the TCAD model to simulate the linear region transfer characteristic curve of the transistor under low drain-source voltage and extract the electrical characteristic parameters respectively until the error between the final adjusted electrical characteristic parameters and the electrical characteristic parameters under the standard model is less than the preset threshold.

[0033] Specifically, the channel doping concentration distribution and gate work function parameters in the transistor TCAD model are adjusted first, and then the carrier mobility parameters are calibrated. Ultimately, the error between the electrical characteristic parameters after adjusting the TCAD model parameters and the electrical characteristic parameters under the standard model is less than a preset threshold. The steps include: Step S301: Adjust the channel doping concentration distribution and gate work function parameters in the current TCAD model, and use the current TCAD model to simulate the linear region transfer characteristic curve Id10 of the transistor under low drain-source voltage. Extract the second threshold voltage Vth1 and the second current curve Id11 of the subthreshold swing region, so that the parameter error e1 between the second threshold voltage Vth1 and the first threshold voltage Vth0 is less than the first preset threshold A, and the curve error e2 between the second current curve Id11 of the subthreshold swing region and the first current curve Id01 is less than the first preset threshold A. Step S302: Adjust the carrier mobility parameters in the transistor TCAD model, and re-simulate the linear region transfer characteristic curve Id10 of the transistor under low drain-source voltage using the TCAD model. Extract the second transconductance Gm1 and the second current curve Id12 in the strong inversion region, so that the parameter error e3 between the second transconductance Gm1 and the first transconductance Gm0 in the strong inversion region is less than the first preset threshold A, and the curve error e4 between the second current curve Id12 and the first current curve Id02 in the strong inversion region is less than the first preset threshold A. Step S303. If the curve errors e1 and e3 and the parameter errors e2 and e4 are all less than the first preset threshold A, then proceed to step S4.

[0034] Preferably, the first preset threshold A can be set according to A≤10%. For example, the parameter error e1 between Vth1 and Vth0 can be set to be less than 10%, the curve error e2 between Id11(Vg) and Id01(Vg) can be less than 10%, the parameter error e3 between Gm1(Vg) and Gm0(Vg) can be less than 10%, and the curve error e4 between Id12(Vg) and Id02(Vg) can be less than 10%. If the parameter errors e1, e2, e3 and e4 are all less than 10%, then proceed to step S4; otherwise, return to step S3.

[0035] Specifically, the parameter error e1 between the second threshold voltage Vth1 and the first threshold voltage Vth0 can be defined as follows: The curve error e2 between the second current curve Id11(Vg) and the first current curve Id01(Vg) in the subthreshold oscillation region can be defined as... The parameter error e3 between the second transconductance Gm1 and the first transconductance Gm0 in the strong inversion region can be defined as follows: The curve error e4 between the second current curve Id12(Vg) and the first current curve Id02(Vg) in the strong inversion region can be defined as... .

[0036] Step S4: Simulate the first saturation region transfer characteristic curve Id20 of the transistor using the standard model at the rated drain-source operating voltage. Adjust the source / drain contact resistance parameters in the transistor TCAD model and simulate the second saturation region transfer characteristic curve Id30 of the transistor using the TCAD model at the rated drain-source operating voltage until the error between the first saturation region transfer characteristic curve Id20 and the second saturation region transfer characteristic curve Id30 is less than a preset threshold.

[0037] In this embodiment, the standard model can specifically use the standard SPICE model.

[0038] In this embodiment, the source / drain contact resistance parameters in the transistor TCAD model are adjusted until the curve error e5 between the second saturation region transfer characteristic curve Id30 and the first saturation region transfer characteristic curve Id20 is less than the first preset threshold A.

[0039] Specifically, the first preset threshold A can be set according to A≤10%, and the curve error e5 between the second saturation region transfer characteristic curve Id30(Vg) and the first saturation region transfer characteristic curve Id20(Vg) can be defined as follows: .

[0040] Step S5: Simulate the first output characteristic curve Id0 of the transistor under the rated gate voltage using a standard model (such as the standard SPICE model), and extract the first saturation current Isat0 and the first output resistance R0. Adjust the saturation velocity and high field mobility degradation parameters in the transistor's TCAD model, and simulate the second output characteristic curve Id1 of the transistor under the rated gate voltage using the TCAD model. Extract the second saturation current Isat1 and the second output resistance R1 until the parameter error between the second saturation current Isat1 and the second output resistance R1 and the first saturation current Isat0 and the first output resistance R0 is less than a preset threshold.

[0041] In this embodiment, the saturation velocity and high field mobility degradation parameters in the transistor TCAD model are adjusted until the parameter error e6 between the second saturation current Isat1 and the first saturation current Isat0 is less than the first preset threshold A, and the parameter error e7 between the second output resistor R1 and the first output resistor R0 is less than the first preset threshold A.

[0042] Specifically, the parameter error e6 between Isat1 and Isat0 can be defined as... The parameter error e7 between R1 and R0 can be defined as... .

[0043] Step S6: Perform simulation based on the transistor TCAD model information obtained from the current calibration to obtain the distribution data of electron-hole pairs and the concentration of electron-hole pairs in the transistor after radiation.

[0044] Specifically, the calibrated transistor TCAD model information can be imported into Geant4, a nuclear physics simulation tool based on the Monte Carlo method, to simulate the process of instantaneous radiation acting on the transistor. Geant4 tracks the transport of all primary and secondary particles, obtains the distribution data of electron-hole pairs in the transistor after radiation, and extracts the first electron-hole pair concentration, which includes the electron-hole pair concentration n00 at the center of the drain region, the electron-hole pair concentration n01 at the center of the channel, the electron-hole pair concentration n02 at the center of the well, and the electron-hole pair concentration n03 at the center of the substrate.

[0045] Step S7: Adjust the parameters describing the instantaneous dose rate radiation effect in the TCAD model obtained by the current calibration to simulate the process of instantaneous radiation acting on a transistor without applied bias voltage, obtain the distribution data of electron-hole pairs and the concentration of electron-hole pairs in the transistor when the dose rate of the radiation pulse is at its peak, until the error between the distribution data of electron-hole pairs and the concentration of electron-hole pairs obtained in step S6 is less than a preset threshold, and obtain the final calibrated TCAD model.

[0046] Specifically, by adjusting the parameters DoseRate, DoseTime, DoseTSigma, and g0 in the TCAD model that describe the instantaneous dose rate radiation effect, and shorting the source, drain, gate, and well contacts of the transistor, the process of instantaneous radiation acting on a transistor without applied bias voltage can be simulated. This allows obtaining the distribution data of electron-hole pairs in the transistor when the dose rate of the radiation pulse is at its peak, and extracting the second electron-hole pair concentration. The second electron-hole pair concentration includes the electron-hole pair concentration n10 at the center of the drain region and the electron-hole pair concentration n10 at the center of the channel. The concentrations n11, n12, and n13 of electron-hole pairs at the center of the trap are set such that the parameter error between the second electron-hole pair concentration and the first electron-hole pair concentration is less than a second preset threshold B, the parameter error e8 between n10 and n00 is less than the second preset threshold B, the parameter error e9 between n11 and n01 is less than the second preset threshold B, the parameter error e10 between n12 and n02 is less than the second preset threshold B, and the parameter error e11 between n13 and n03 is less than the second preset threshold B.

[0047] Preferably, the second preset threshold B can be set to B≤30%.

[0048] Furthermore, considering that simulation tools (such as Geant4) do not consider the influence of electric field on electron-hole pairs during the simulation of TCAD models, this invention further adjusts the connection method of transistors during TCAD calibration (such as short-circuiting the source, drain, gate, and well contacts, with the corresponding calibration positions being the center of the drain region, the center of the channel, and the center of the well where the electric field is weakest). This ensures that the simulation conditions of the simulation tool and the TCAD model are kept as consistent as possible, thereby further improving the calibration accuracy.

[0049] More preferably, the low drain-source voltage can be between 0.01V and 0.2V, and the rated drain-source operating voltage is the integrated circuit operating voltage VDD recommended by the CMOS integrated circuit process, which can be between 0.6V and 5V. Similarly, the rated gate voltage is the integrated circuit operating voltage VDD recommended by the CMOS integrated circuit process, which can be between 0.6V and 5V.

[0050] The following example, using the TCAD model calibration for simulating the instantaneous dose rate radiation effect of a FinFET process NMOS transistor using the method described above, further illustrates the present invention. Figure 2 As shown, the specific steps include: Step S1: Extract the standard SPICE model from the FinFET process design kit (PDK), read its defined device structure parameters (such as gate length, gate oxide thickness, junction depth) and basic physical parameters, and build the initial TCAD model of the NMOS transistor in the TCAD environment; Step S2: Using the standard SPICE model, the drain-source voltage V ds The linear region transfer characteristic curve Id00(Vg) of the simulated NMOS transistor at 0.05V was used to extract the threshold voltage Vth0 and the subthreshold swing region. The current Id01(Vg) of the strong inversion region ( The transconductance Gm0(Vg) and current curve Id02(Vg) are shown. Step S3: Step S301: Adjust the channel doping concentration distribution and gate work function parameters in the NMOS transistor TCAD model, and use the TCAD model to simulate the linear region transfer characteristic curve Id10(Vg) of the transistor at low drain-source voltage, extracting the threshold voltage Vth1 and the subthreshold swing region ( The current curve Id11(Vg) is such that the parameter error e1 between Vth1 and Vth0 is less than 10%, and the curve error e2 between Id11(Vg) and Id01(Vg) is less than 10%. Step S302: Adjust the carrier mobility parameters in the NMOS transistor TCAD model, and re-simulate the linear region transfer characteristic curve Id10(Vg) of the NMOS transistor under low drain-source voltage using the TCAD model, and extract the strong inversion region ( The transconductance Gm1(Vg) and current curve Id12(Vg) are such that the parameter error e3 between Gm1(Vg) and Gm0(Vg) is less than 10%, and the curve error e4 between Id12(Vg) and Id02(Vg) is less than 10%. Step S303: If e1, e2, e3 and e4 are all less than 10%, proceed to S4; otherwise, proceed to S301. Step S4: Using a standard SPICE model, calculate the drain-source voltage V. ds Simulated saturation region transfer characteristic curve Id20(Vg) of NMOS transistor at 0.9V; adjusted the source / drain contact resistance parameters in the NMOS transistor TCAD model, and used the TCAD model at drain-source voltage V dsThe saturation region transfer characteristic curve Id30(Vg) of the simulated transistor at 0.9V is obtained, and the curve error e5 between Id30(Vg) and Id20(Vg) is less than 10%. Step S5: Use the standard SPICE model in V gs Simulate the output characteristic curve Id0(Vd) of the transistor at 0.9V, extract the saturation current Isat0 and output resistance R0; adjust the saturation velocity and high field mobility degradation parameters in the TCAD model of the NMOS transistor, and use the TCAD model at V... gs Simulate the output characteristic curve Id1(Vd) of the transistor at 0.9V, extract the saturation current Isat1 and the output resistance R1, and make the parameter error e6 between Isat1 and Isat0 less than 10%, and the parameter error e7 between R1 and R0 less than 10%; if e5, e6 and e7 are all less than 10%, go to S6, otherwise go to S5. Step S6: Import the calibrated NMOS transistor TCAD model information into Geant4, a nuclear physics simulation tool based on the Monte Carlo method, to simulate the process of transient radiation (such as a gamma-ray pulse) acting on the NMOS transistor. Geant4 tracks the transport of all primary and secondary particles to obtain the distribution data of electron-hole pairs in the transistor after radiation. Extract the electron-hole pair concentration n00 at the center of the drain region, n01 at the center of the channel, n02 at the center of the well, and n03 at the center of the substrate. Step S7: Adjust the parameters DoseRate, DoseTime, DoseTSigma, and g0 in the TCAD model that describe the instantaneous dose rate radiation effect. Short-circuit the source, drain, gate, and well contacts of the NMOS transistor. Simulate the process of instantaneous radiation (such as a gamma-ray pulse) acting on an NMOS transistor without applied bias voltage. Obtain the distribution data of electron-hole pairs in the NMOS transistor when the dose rate of the radiation pulse is at its peak. Extract the electron-hole pair concentration n10 at the center of the drain region, n11 at the center of the channel, n12 at the center of the well, and n13 at the center of the substrate. Ensure that the parameter error e8 between n10 and n00 is less than 10%, the parameter error e9 between n11 and n01 is less than 10%, the parameter error e10 between n12 and n02 is less than 10%, and the parameter error e11 between n13 and n03 is less than 10%. The TCAD model calibration of the FinFET process NMOS transistor is complete.

[0051] This embodiment further provides a TCAD model calibration system, including a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to execute the computer program to perform the method described above.

[0052] It is understood that the method described in this embodiment can be executed by a single device, such as a computer or server, or it can be applied to a distributed scenario where multiple devices cooperate to complete the task. In a distributed scenario, one of the multiple devices may execute only one or more steps of the method described in this embodiment, and the multiple devices interact to complete the method. The processor can be implemented using a general-purpose CPU, microprocessor, application-specific integrated circuit, or one or more integrated circuits, and is used to execute relevant programs to implement the method described in this embodiment. The memory can be implemented using read-only memory (ROM), random access memory (RAM), static storage devices, and dynamic storage devices. The memory can store the operating system and other applications. When the method described in this embodiment is implemented through software or firmware, the relevant program code is stored in the memory and called and executed by the processor.

[0053] This embodiment further provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described above.

[0054] Those skilled in the art will understand that the above embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-readable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The present invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, produce implementations of the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 The computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1The functions specified in one or more boxes. These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable apparatus for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0055] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Therefore, any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention should fall within the protection scope of the present invention.

Claims

1. A method for calibrating a TCAD model of instantaneous dose rate radiation effects, characterized in that the steps include: include: Step S1: Construct the initial TCAD model of the transistor in the TCAD environment; Step S2: Simulate the linear region transfer characteristic curve Id00 of the transistor under low drain-source voltage using the standard model, and extract the electrical characteristic parameters under the standard model. The electrical characteristic parameters include the threshold voltage, the current in the subthreshold swing region, and the transconductance and current curves in the strong inversion region. Step S3: Sequentially adjust the channel doping concentration distribution, gate work function parameter, and carrier mobility parameter in the TCAD model of the transistor. After each adjustment, use the TCAD model to simulate the linear region transfer characteristic curve of the transistor under low drain-source voltage and extract the electrical characteristic parameters respectively until the error between the final adjusted electrical characteristic parameters and the electrical characteristic parameters under the standard model is less than a preset threshold. Step S4: Simulate the first saturation region transfer characteristic curve Id20 of the transistor using the standard model at the rated drain-source operating voltage, adjust the source / drain contact resistance parameters in the transistor TCAD model, and simulate the second saturation region transfer characteristic curve Id30 of the transistor using the TCAD model at the rated drain-source operating voltage until the error between the first saturation region transfer characteristic curve Id20 and the second saturation region transfer characteristic curve Id30 is less than the preset threshold. Step S5: Simulate the first output characteristic curve Id0 of the transistor under rated gate voltage using the standard model, and extract the first saturation current Isat0 and the first output resistance R0. Adjust the saturation velocity and high field mobility degradation parameters in the transistor's TCAD model, and simulate the second output characteristic curve Id1 of the transistor under rated gate voltage using the TCAD model. Extract the second saturation current Isat1 and the second output resistance R1 until the parameter error between the second saturation current Isat1 and the second output resistance R1 and the first saturation current Isat0 and the first output resistance R0 is less than a preset threshold. Step S6: Perform simulation based on the TCAD model information obtained from the current calibration to obtain the distribution data of electron-hole pairs and the concentration of electron-hole pairs in the transistor after radiation; Step S7: Adjust the parameters describing the instantaneous dose rate radiation effect in the TCAD model obtained by the current calibration to simulate the process of instantaneous radiation acting on a transistor without applied bias voltage, obtain the distribution data of electron-hole pairs and the concentration of electron-hole pairs in the transistor when the dose rate of the radiation pulse is at its peak, until the error between the distribution data of electron-hole pairs and the concentration of electron-hole pairs obtained in step S6 is less than a preset threshold, and obtain the final calibrated TCAD model.

2. The instantaneous dose rate radiation effect TCAD model calibration method according to claim 1, characterized in that, Step S1 includes: extracting a standard SPICE model from the FinFET process design kit PDK, reading the defined device structure parameters and basic physical parameters, and constructing an initial TCAD model of the NMOS transistor in the TCAD environment. The device structure parameters include gate length, gate oxide thickness, and junction depth.

3. The instantaneous dose rate radiation effect TCAD model calibration method according to claim 1, characterized in that, The subthreshold swing region is the region that satisfies 0≤|Vg|≤|Vth0|, and the strong inversion region is the region that satisfies |Vth0|≤|Vg|≤VDD, where |Vg| is the voltage value, VDD is the operating power supply voltage, and Vth0 is the first threshold voltage.

4. The instantaneous dose rate radiation effect TCAD model calibration method according to claim 1, characterized in that, In step S2, the extracted electrical characteristic parameters under the standard model include the first threshold voltage Vth0, the first current curve Id01 in the subthreshold swing region, and the first transconductance Gm0 and the first current curve Id02 in the strong inversion region; step S3 includes: Step S301: Adjust the channel doping concentration distribution and gate work function parameters in the current TCAD model, and use the current TCAD model to simulate the linear region transfer characteristic curve Id10 of the transistor under low drain-source voltage. Extract the second threshold voltage Vth1 and the second current curve Id11 of the subthreshold swing region, so that the parameter error e1 between the second threshold voltage Vth1 and the first threshold voltage Vth0 is less than the first preset threshold A, and the curve error e2 between the second current curve Id11 of the subthreshold swing region and the first current curve Id01 is less than the first preset threshold A. Step S302: Adjust the carrier mobility parameters in the transistor TCAD model, and re-simulate the linear region transfer characteristic curve Id10 of the transistor under low drain-source voltage using the TCAD model. Extract the second transconductance Gm1 and the second current curve Id12 of the strong inversion region, so that the parameter error e3 between the second transconductance Gm1 and the first transconductance Gm0 in the strong inversion region is less than the first preset threshold A, and the curve error e4 between the second current curve Id12 and the first current curve Id02 in the strong inversion region is less than the first preset threshold A. Step S303. If the parameter errors e1, e3 and the curve errors e2, e4 are all less than the first preset threshold A, then proceed to step S4.

5. The instantaneous dose rate radiation effect TCAD model calibration method according to claim 4, characterized in that, In step S4, the source / drain contact resistance parameters in the transistor TCAD model are adjusted until the curve error e5 between the second saturation region transfer characteristic curve Id30 and the first saturation region transfer characteristic curve Id20 is less than the first preset threshold A. In step S5, the saturation velocity and high field mobility degradation parameters in the transistor TCAD model are adjusted until the parameter error e6 between the second saturation current Isat1 and the first saturation current Isat0 is less than the first preset threshold A, and the parameter error e7 between the second output resistance R1 and the first output resistance R0 is less than the first preset threshold A.

6. The instantaneous dose rate radiation effect TCAD model calibration method according to any one of claims 1 to 5, characterized in that, Step S6 includes: importing the TCAD model information obtained from the current calibration into Geant4, a nuclear physics simulation tool based on the Monte Carlo method, to simulate the process of instantaneous radiation acting on the transistor. During the simulation, the transport of all primary and secondary particles is tracked to obtain the distribution data of electron-hole pairs in the transistor after radiation and to extract the first electron-hole pair concentration. The first electron-hole pair concentration includes the electron-hole pair concentration n00 at the center of the drain region, the electron-hole pair concentration n01 at the center of the channel, the electron-hole pair concentration n02 at the center of the well, and the electron-hole pair concentration n03 at the center of the substrate.

7. The instantaneous dose rate radiation effect TCAD model calibration method according to claim 6, characterized in that, Step S7 includes: adjusting the DoseRate, DoseTime, DoseTSigma, and g0 parameters in the TCAD model obtained from the current calibration to describe the instantaneous dose rate radiation effect, in order to simulate the process of instantaneous radiation acting on a transistor without applied bias voltage, obtaining the distribution data of electron-hole pairs in the transistor when the dose rate of the radiation pulse is at its peak, and extracting the second electron-hole pair concentration. The second electron-hole pair concentration includes the electron-hole pair concentration n10 at the center of the drain region, the electron-hole pair concentration n11 at the center of the channel, the electron-hole pair concentration n12 at the center of the well, and the electron-hole pair concentration n13 at the center of the substrate, so that the parameter error between the second electron-hole pair concentration and the first electron-hole pair concentration is less than a second preset threshold B.

8. The instantaneous dose rate radiation effect TCAD model calibration method according to any one of claims 1 to 5, characterized in that, Step S7 also includes shorting the source, drain, gate, and well contacts of the transistor in the TCAD model to maintain consistency with the simulation conditions in step S6.

9. A TCAD model calibration system, comprising a processor and a memory, wherein the memory is used to store computer programs, characterized in that, The processor is configured to execute the computer program to perform the method as described in any one of claims 1 to 8.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1 to 8.

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