A modeling method and system for neutron radiation effects in a triode

Abstract

The application belongs to the technical field of modeling of microelectronic device irradiation effect model, and discloses a modeling method and system of neutron radiation effect of a triode, the modeling method comprising: selecting or designing an original device; obtaining model data of the original triode device; extracting an input V-I characteristic curve of a base port and an output V-I characteristic curve of a collector and an emitter port; extracting base input impedance model parameters according to the base characteristic curve and triode output model parameters according to the output characteristic curve; obtaining basic device parameters such as a triode current amplification factor in combination with the input and output characteristic curves; establishing a triode device physical model according to the model parameters; and establishing a neutron radiation effect model of the triode device base, collector and emitter port according to the device electrical characteristic degradation caused by the neutron radiation effect; the model established by the application can reflect the basic device characteristics of the triode device and provide model support for system simulation under irradiation conditions.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electronic device irradiation effect modeling, and particularly relates to a modeling method and system for neutron radiation effects of a triode. BACKGROUND

[0002] At present, with the rapid development of semiconductor technology, various analog device models are widely used in the fields of aerospace, nuclear industry and particle physics, etc. They are in various electromagnetic, high-energy particle radiation environments, and are affected by neutron radiation, single-particle radiation and transient effects and other radiation effects, and their working reliability and life cycle are severely tested. Among them, the neutron radiation effect has been widely concerned and researched.

[0003] In recent years, with the development of computer simulation technology, electronic system radiation effect simulation provides strong support for system radiation resistance design and theoretical research, which shortens the research and development period and reduces the development cost. At present, the modeling research of neutron radiation effects of device models (Petrosyants K, Vologdin E, Smirnov D, et al. Si BJT and SiGe HBT performance modeling after neutron radiation exposure [C] / / Design&Test Symposium. IEEE, 2011: 267-270.) mainly includes two types of transistor-level models (SPICE models) based on bottom-layer physics and function-based behavior models. The transistor-level model has high simulation accuracy and wide application range, but its calculation overhead is large, the circuit scale of simulation is limited, and since the physical model involves intellectual property information, semiconductor manufacturers are often unwilling to provide the corresponding model or encrypt the model, which makes it difficult to be used for neutron radiation effect modeling work. The behavior-level model does not involve bottom-layer physics, and the model is simple, universal and high in simulation efficiency, but the working point described by the model is fixed, different power supply voltages correspond to different models, so it cannot accurately describe the characteristics when the chip power supply voltage is not the set value. When modeling the neutron radiation effects of devices, a model can only describe the electrical characteristics at a specific neutron radiation point, and cannot accurately and continuously represent the electrical characteristics of the device under different conditions.

[0004] In summary, the existing technology has the disadvantage that the neutron radiation effect modeling method of the device model can only represent the behavior characteristics of the digital device port, and cannot accurately and continuously represent the electrical characteristics of the device under different conditions. SUMMARY

[0005] In order to overcome the shortcomings of the prior art, the present application aims to provide a modeling method and system for the neutron radiation effect of a triode, which can reflect the behavior characteristics of the device and the physical characteristics of the device port, and can reflect the functional degradation of the device caused by the influence of the neutron radiation effect on the device port through the changes in the physical model parameters of the device port.

[0006] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0007] A modeling method for the neutron radiation effect of a triode, comprising the following steps:

[0008] Step 1: selecting or designing a device as an original triode device;

[0009] Step 2: measuring the model data of the original triode device by an instrument or downloading the model data of the original triode device from the official website of the component;

[0010] Step 3: extracting the input port V-I characteristic curve and the output port V-I characteristic curve based on the model data;

[0011] Step 4: extracting the working data of the triode in different working zones according to the input port V-I characteristic curve and the output port V-I characteristic curve;

[0012] Step 5: calculating the model parameters such as the base input impedance and the current amplification factor according to the input and output working data of the triode in the amplification zone;

[0013] Step 6: establishing a triode physical model based on the original SPICE model of the triode according to the calculated model parameters;

[0014] Step 7: obtaining the relationship between the triode parameters and the irradiation parameters according to the changes in the device parameters caused by the neutron radiation effect, that is, establishing a triode irradiation parameter model;

[0015] Step 8: establishing a triode neutron radiation effect model according to the electrical characteristic degradation of the device caused by the neutron radiation effect.

[0016] The step 1 and the step 2 are used to obtain the basic model data of a certain device, and prepare for the subsequent modeling work; the step 3 is used to extract the device characteristic curve, and prepare for extracting the model parameters; the step 4 is used to prepare for subsequent calculation of the physical device parameters of the triode physical model and selection of the interval of the test data; the step 5 is used to obtain the model physical parameters, and prepare for constructing the triode physical model with physical characteristics; the step 6 is used to establish the triode physical model, that is, the triode model without adding the radiation effect parameters, so as to facilitate adding the neutron radiation effect on this basis; the step 7 is used to accurately extract the change of the triode physical parameters caused by the irradiation effect, and obtain the change relationship between the triode physical parameters and the irradiation parameters; and the step 8 is used to consider the influence of the neutron radiation effect on the port impedance and other electrical characteristics of the triode on the basis of the triode physical model established in the step 6 and the change relationship between the triode physical parameters and the irradiation parameters obtained in the step 7, and finally establish the triode neutron radiation effect model.

[0017] In the steps 1 and 2, the data of the original triode device is collected, including: the V-I and I-I data of the original triode device are measured by using the SPICE simulation method or the method of directly measuring the real device; the IV data represent the current-voltage relationship, including the base input Ibe-Vbe data and the collector Ice-Vce data; the Ibe-Ice data represent the amplification factor relationship of the collector current and the base current, including the working current and the current amplification factor in different working zones.

[0018] In the step 3, when the input V-I characteristic curve of the base input port is extracted based on the model, the NPN triode is used, Vbe represents the voltage between the model base and the emitter, Ibe represents the current flowing through, the lowest base on voltage of the triode is obtained by calculation, and the input impedance characteristic curve after turning on is obtained.

[0019] The step 4 includes: based on the obtained input port V-I characteristic curve and the output port V-I characteristic curve, a plurality of reference points are selected, the triode working curve graph under normal state is drawn according to the reference point data, and the Vce and Vbe ranges in different working zones are obtained according to the different change trends and working states of Ic in the curve graph, wherein: the saturation zone working state is represented by the approximate linear relationship of Ic-Vce, the amplification zone working state is represented by the invariance of Ib and Ic with Vce, and the cutoff zone working state is represented by Ib being 0 and Ic being almost 0.

[0020] Step 5 includes: according to the data obtained in step 4, adjusting the base input current, the collector power supply voltage, ensuring that the working state of the transistor is in the amplification zone and testing the input and output data when it works; then, according to the input port V-I characteristic curve, selecting several reference points on the input port V-I characteristic curve, and using the least square method to fit the model equation to fit the base current-voltage characteristic curve of the transistor, so as to obtain the base input impedance parameters of the transistor in the model equation;

[0021] According to the data obtained from the working curve of the transistor, adjust the base input current, the collector power supply voltage, ensure that the working state of the transistor is in the amplification zone and test the input and output data when it works; select several reference points for testing, and according to the collector current Ic and the base current Ib, the current amplification coefficient under normal conditions is obtained through the formula β = Ic / Ib.

[0022] Step 6 includes: according to the test fitting result, establishing an impedance transformation network model according to the obtained base input impedance equation, and connecting it to the input end of the SPICE model; according to the current amplification coefficient parameters under normal conditions measured in the previous steps, modify the SPICE model parameters.

[0023] Step 7 includes: according to the measured working data of the transistor device model under different irradiation conditions, reusing the calculation method in steps 3-6 to calculate the device parameters under different irradiation conditions, also using the least square method to fit, and combining the irradiation dose to fit and construct the irradiation dose-parameter change relationship formula, including input impedance, amplification zone current amplification coefficient, etc.

[0024] The threshold voltage and carrier mobility of the original transistor device output port switching transistor are established to form a neutron radiation effect model, that is, a neutron radiation effect model of the transistor digital IC output port.

[0025] Step 8 includes: introducing the neutron radiation parameter D in the transistor neutron radiation effect model file, and calculating the actual model parameters under the neutron radiation D according to the input model of the neutron radiation D and modifying the SPICE model parameters and input impedance transformation model during simulation.

[0026] A transistor neutron radiation effect modeling system applying the transistor neutron radiation effect modeling method, comprising:

[0027] An original transistor device acquisition module is used to select or design a device as an original transistor device;

[0028] A model data acquisition module is used to measure the model data of the original transistor device by an instrument or download the model data of the original transistor device from the official website of the component;

[0029] a characteristic curve extraction module extracts input VI characteristic curves of the base port and VI characteristic curves of the output port based on the model data;

[0030] a model parameter extraction module extracts parameters such as working conditions of the triode in different working zones, input impedance of the triode base, and current amplification coefficient according to the input port V-I characteristic curves and the output port V-I characteristic curves;

[0031] a SPICE model correction module establishes a triode physical model based on the original SPICE model according to the calculated model parameters;

[0032] a radiation parameter equation construction module establishes a triode radiation parameter model according to triode parameter changes caused by neutron radiation effects;

[0033] a neutron radiation effect model construction module establishes a triode neutron radiation effect model according to device electrical characteristic degradation caused by neutron radiation effects.

[0034] The modeling method of the present application has the advantages of clear model principle and fast modeling speed, because the modeling method is based on the SPICE model to establish a triode physical model, and the triode neutron radiation effect model is obtained by modifying the triode physical model according to the irradiation test results. Meanwhile, the modeling method of the present application is a method of modeling the electrical characteristics of the simulated device under irradiation conditions, and the established triode neutron radiation effect model can be directly used for simulation analysis of electronic systems under irradiation conditions. The present application improves the general SPICE model and the behavior level modeling method based on the model, and the established triode neutron radiation effect model can accurately reflect the simulation characteristics of a specific triode, thereby providing model support for system simulation under irradiation conditions.

[0035] The present application can reflect the behavior characteristics of the device, characterize the physical characteristics of the device port, and reflect the functional degradation of the device caused by the influence of neutron radiation effects on the device port through the physical model parameter changes of the device port. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 is a modeling method flow chart of the triode neutron radiation effect of the embodiment of the present application.

[0037] Figure 2 is a modeling system structure block diagram of the triode neutron radiation effect of the embodiment of the present application. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below with reference to the embodiments. It should be understood that the embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0039] As shown in Figure 1 A modeling method of triode neutron radiation effect, comprising the following steps:

[0040] S101: selecting or designing a digital device as an original triode device;

[0041] S102: measuring the original triode device with an instrument or obtaining model data of the original triode device from the official website of the component;

[0042] S103: extracting input port V-I characteristic curve and output port V-I characteristic curve based on the model data;

[0043] S104: extracting working data of the triode in different working areas according to the input port V-I characteristic curve and the output port V-I characteristic curve;

[0044] S105: calculating base input impedance, current amplification coefficient and other parameters according to the input and output working data of the triode in the amplification area;

[0045] S106: establishing a corrected triode physical model based on the original SPICE model of the triode according to the calculated model parameters;

[0046] S107: establishing a triode irradiation parameter model according to the device parameter changes caused by the neutron radiation effect;

[0047] S108: establishing a triode neutron radiation effect model according to the device electrical property degradation caused by the neutron radiation effect.

[0048] As shown in Figure 2 The embodiment of the present application is a modeling system of triode neutron radiation effect, comprising:

[0049] An original triode device acquisition module is used to select or design a device as an original triode device;

[0050] A model data acquisition module is used to measure the original triode device with an instrument or obtain model data of the original triode device from the official website of the component;

[0051] A characteristic curve extraction module is used to extract input port V-I characteristic curve and output port V-I characteristic curve based on the model data;

[0052] A model parameter extraction module is used to extract triode working conditions in different working areas, triode base input impedance, current amplification coefficient and other parameters according to the input port V-I characteristic curve and the output port V-I characteristic curve;

[0053] A SPICE model correction module is used to establish a triode physical model based on the original SPICE model according to the calculated model parameters;

[0054] The irradiation parameter equation construction module establishes a triode irradiation parameter model according to triode parameter changes caused by neutron radiation effects;

[0055] The neutron radiation effect model construction module establishes a triode neutron radiation effect model according to device electrical property degradation caused by neutron radiation effects.

[0056] In Example 1, a triode 2N2222 is used as a test and modeling device for an original triode device. In order to obtain the working data of the original triode device, a real device direct measurement method is used to measure I-V data, I-I data (I-V data represents current-voltage relationship, including base input Ibe-Vbe data and collector Ice-Vce data; the I-I data represents collector current Ice and base current Ibe data), etc., and the data is recorded in a file.

[0057] The working data of the 2N2222 triode in different working zones is determined according to the base current Ib, collector current Ic, and collector-emitter voltage Vce. Based on the above parameters, a number of reference points are selected, and the input port V-I characteristic curve and the output port V-I characteristic curve of the triode under normal conditions are drawn according to the reference point data, and then the parameters of the general triode SPICE model are adjusted according to the content of the relationship curve diagram.

[0058] According to the data obtained from the 2N2222 triode working curve diagram, the base input current and the collector supply voltage are adjusted to ensure that the triode working state is in the amplification zone and the input and output data during operation are tested. Then, according to the input port V-I characteristic curve and the output port V-I characteristic curve, a number of reference points are selected on the base input characteristic curve, and the input port V-I characteristic curve is fitted by using the least square method to fit the model equation, so as to obtain the input impedance parameters of the triode in the model equation. According to the obtained input impedance equation, an impedance transformation network model is established and connected to the input end of the SPICE model.

[0059] According to the data obtained from the triode working curve diagram, the base input current and the collector supply voltage are adjusted to ensure that the triode working state is in the amplification zone and the input and output data during operation are tested. A number of reference points are selected for testing, and the current amplification factor under normal conditions is obtained by the formula β = Ic / Ib according to the collector current Ic and the base current Ib, and the SPICE model parameters are modified.

[0060] Then, the working data of the 2N2222 device at three total dose points (1E10, 3E12 and 1E13) are determined, the device parameters under different irradiation conditions are calculated by the repeated calculation method, and the irradiation dose-variation equation of each parameter, including the input impedance and the current amplification factor in the amplification zone, is constructed by combining the irradiation dose fitting.

[0061] The neutron irradiation parameter D is introduced in the model file of the neutron irradiation effect of the triode, the actual model parameters under the neutron irradiation D are calculated according to the input model of the neutron irradiation D during simulation, and the SPICE model parameters and the input impedance transformation model are modified.

[0062] It can be known from the test experiment that, with the increase of the fluence, the base current continuously decreases under the same base voltage, and the current amplification factor in the amplification zone of the 2N2222 triode continuously increases. The base voltage and the current under different doses are shown in Table 1, and the current amplification factors under different doses are shown in Table 2, and the typical values are 227.5363, 172.6369 and 123.2686 respectively. Then, the device established by the steps of the application is simulated and compared with the experimental data, and the results are shown in Tables 3 and 4 respectively. The base current error under different fluences is 1.76%, 0.02% and 4.62% respectively, and the current amplification factor error is 0.11%, 1.42% and 2.84% respectively. It can be seen from the comparison of the simulation results and the real experimental results that the model can better reflect the neutron irradiation effect of the triode device.

[0063] Table 1

[0064]

[0065] Table 2

[0066] Injection amount (n / cm 2 ) Current amplification factor 1e10 227.5363 3e12 172.6369 1e13 123.2686

[0067] Table 3

[0068] Fluence Irradiation results (A) Simulation results (A) Relative deviation 1e10 744.4847e-9 757.5697e-9 1.76％ 3e12 1.5414e-6 1.54165e-6 0.016％ 1e13 4.2269e-6 4.03172e-6 4.62％

[0069] Table 4

[0070] Fluence Irradiation results Simulation results Relative deviation 1e10 227.5363 227.77898 0.11％ 3e12 172.6369 175.09488 1.42％ 1e13 123.2686 126.7672 2.84％

[0071] The above describes only specific embodiments of the application, but the protection scope of the application is not limited thereto, any modification, equivalent replacement and improvement made by those skilled in the art within the technical range disclosed by the application and in the spirit and principle of the application should be covered within the protection scope of the application.

Claims

1. A method of modeling the effects of neutron irradiation on a triode, characterized by, The method comprises the following steps: Step 1: selecting or designing a digital device as an original triode device; Step 2: measuring or downloading model data of the original triode device from the official website of the device; Step 3: extracting input port V-I characteristic curve and output port V-I characteristic curve of the base port based on the model data; Step 4: extracting working conditions of the triode in different working zones according to the input port V-I characteristic curve and the output port V-I characteristic curve; Step 5: calculating model parameters of the base input impedance and the current amplification coefficient according to the input and output working data of the triode in the amplification zone; Step 6: establishing a triode physical model based on the original SPICE model of the triode according to the calculated model parameters; Step 7: obtaining a triode parameter-irradiation parameter relationship formula according to the device parameter changes caused by the neutron irradiation effect, that is, establishing a triode irradiation parameter model; specifically including: re-calculating the device parameters of the triode under different irradiation conditions by using the calculation method in steps 3-6, similarly using the least square method to fit, and combining the irradiation dose to fit and construct the irradiation dose-parameter change equation, including the input impedance and the amplification zone current amplification coefficient; establishing a neutron irradiation effect model for the threshold voltage and carrier mobility of the output port switch transistor of the original triode device, that is, a neutron irradiation effect model for the triode digital IC output port; Step 8: establishing a triode neutron irradiation effect model according to the device electrical characteristic degradation caused by the neutron irradiation effect; specifically including: introducing the neutron irradiation parameter D in the triode neutron irradiation effect model file, and calculating the actual model parameters under the neutron irradiation D according to the input model neutron irradiation D and modifying the SPICE model parameters and the input impedance transformation model during simulation.

2. The method of claim 1, wherein: In steps 1 and 2, the data collection of the original triode device includes: measuring the V-I and I-I data of the original triode device by using the SPICE simulation method or the real device direct measurement method; the IV data represents the current-voltage relationship, including the base input Ibe-Vbe data and the collector Ice-Vce data; the Ibe-Ice data represents the current amplification factor relationship between the collector current and the base current, including the working current and the current amplification factor in different working zones.

3. The method of claim 1, wherein: In step 3, when the input V-I characteristic curve of the base input port is extracted based on the model, the NPN triode is used, Vbe represents the voltage between the model base and the emitter, Ibe represents the current flowing through, and the lowest base on voltage of the triode and the input impedance characteristic curve after turning on are obtained by calculation.

4. The method of claim 1, wherein, Step 4 includes: based on the obtained base input port V-I characteristic curve and output port V-I characteristic curve, selecting several reference points, drawing the normal triode working curve according to the reference point data, and obtaining the Vce, Vbe range in different working zones according to the different change trend of Ic in the curve and the working state, wherein: the saturation zone working state is represented as the approximate linear relationship of Ic-Vce, the amplification zone working state is represented as Ib and Ic not changing with Vce, and the cutoff zone working state is represented as Ib being 0 and Ic being almost 0.

5. The method of claim 1, wherein: Step 5 includes: according to the data obtained from the normal triode working curve, adjusting the base input current and the collector power supply voltage to ensure that the triode working state is in the amplification zone and test the input and output data when it works; then, according to the input port V-I characteristic curve, selecting several reference points on the input port V-I characteristic curve, and using the least square method to fit the model equation to fit the base current-voltage characteristic curve, to obtain the base input impedance parameters of the triode in the model equation.

6. The method of claim 5, wherein: According to the data obtained from the triode working curve, adjusting the base input current and the collector power supply voltage to ensure that the triode working state is in the amplification zone and test the input and output data when it works; selecting several reference points for testing, and according to the collector current Ic and the base current Ib, the current amplification coefficient in normal state is obtained through the formula β = Ic / Ib.

7. The method of claim 1, wherein: Step 6 includes: according to the test fitting result, establishing an impedance transformation network model according to the obtained base input impedance equation, and connecting it to the SPICE model input end; modifying the SPICE model parameters according to the current amplification coefficient parameters in normal state measured in the previous steps.

8. A triode neutron radiation effect modeling system applying the method of triode neutron radiation effect modeling according to any one of claims 1 to 7, characterized in that It includes: An original triode device acquisition module for selecting or designing a device as an original triode device; A model data acquisition module for measuring or downloading the model data of the original triode device from the official website of the component; A characteristic curve extraction module for extracting the input VI characteristic curve of the base port and the output VI characteristic curve of the port based on the model data; A model parameter extraction module for extracting triode different working zone working conditions, triode base input impedance, current amplification coefficient and other parameters according to the input port V-I characteristic curve and output port V-I characteristic curve; A SPICE model correction module for establishing a corrected triode physical model based on the original SPICE model according to the calculated model parameters; An irradiation parameter equation construction module for establishing a triode irradiation parameter model according to the triode parameter changes caused by neutron radiation effects; A neutron radiation effect model construction module for establishing a triode neutron radiation effect model according to the device electrical property degradation caused by neutron radiation effects.

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