An interface state model construction method, device, system and storage medium

Abstract

The application provides a method, device and system for constructing an interface state model and a storage medium, and relates to the technical field of simulation.The method comprises the following steps: obtaining test data, obtaining a concentration distribution model of an interface state defect according to the test data, determining a surface recombination rate based on the concentration distribution model through a recombination rate formula group, determining an ionized interface state concentration according to the recombination rate formula group and an interface state formula group, constructing a simulation model according to the surface recombination rate and the ionized interface state concentration, performing a simulation test on a transistor according to the concentration distribution model and the simulation model, determining a transfer characteristic curve, and determining a final interface state model according to the simulation model when the transfer characteristic curve meets a preset transfer characteristic curve change range.The technical scheme provided by the application establishes an interface state model, verifies the accuracy of the model through a simulation test, and corrects the problem that the existing interface state model only considers a single energy level.

Description

Technical Field

[0001] This invention relates to the field of simulation technology, and more specifically, to a method, apparatus, system, and storage medium for constructing an interface state model. Background Technology

[0002] The space radiation environment can cause ionization in bipolar devices. The ionization effect damages the SiO2 passivation layer of the bipolar devices and generates interface states at the Si-SiO2 interface, thereby affecting the electrical performance parameters of electronic components. Therefore, it is necessary to perform simulation calculations on interface states to provide a reference for solving the impact of interface state traps on electronic components.

[0003] In existing technologies, when considering the impact of Si-SiO2 interface state defects on device performance in TCAD simulation, only the single energy level of the interface state trap is considered. This results in the fixed properties of the defined interface states during TCAD simulation, and the properties of the interface states do not change with voltage regulation, which is inconsistent with the actual physical meaning. Furthermore, the impact of interface defect states on device performance is the result of the combined effect of each energy level, and it is impossible to accurately consider the Si-SiO2 interface state distribution model under continuous multi-energy level conditions. Summary of the Invention

[0004] The problem addressed by this invention is how to correct the existing interface state model that only considers a single energy level.

[0005] To address the aforementioned problems, this invention provides an interface state model, comprising: acquiring experimental data; obtaining a concentration distribution model of interface state defects based on the experimental data; determining a surface recombination rate based on the concentration distribution model using a set of recombination rate formulas; determining the concentration of ionized interface states based on the recombination rate formulas and the interface state formulas; constructing a simulation model based on the surface recombination rate and the concentration of ionized interface states; conducting simulation experiments on a transistor based on the concentration distribution model and the simulation model to determine a transfer characteristic curve; and determining a final interface state model based on the simulation model when the transfer characteristic curve meets a preset range of change.

[0006] Optionally, obtaining the surface recombination rate based on the concentration distribution model and using the recombination rate formula set includes: combining the recombination rate formula set and using recombination model theory to obtain the surface recombination rate.

[0007] Optionally, the composite rate formula set includes: a fitting model formula, a surface composite rate formula, and a composite rate formula.

[0008] Optionally, the interface state defects include donor defects and acceptor defects.

[0009] Optionally, the energy level of the donor defect is in the range of 0-0.55 eV; the energy level of the acceptor defect is in the range of 0.55-1.1 eV.

[0010] Optionally, the interface state formula set includes: a donor defect ionization probability formula, an acceptor defect ionization probability formula, a donor defect emission rate formula for electrons and holes, an acceptor defect emission rate formula for electrons and holes, and a formula for the concentration of ionized defects in the interface state.

[0011] Optionally, the transistor includes an NMOS transistor and a PMOS transistor.

[0012] The method for constructing the interface state model described in this invention involves acquiring experimental data and obtaining a concentration distribution model of interface state defects based on the experimental data; determining the surface recombination rate using a set of recombination rate formulas based on the above model; determining the concentration of ionized interface states based on the recombination rate formulas and the interface state formulas; constructing a simulation model based on the surface recombination rate and the concentration of ionized interface states; conducting simulation experiments on transistors based on the concentration distribution model and the simulation model to determine the transfer characteristic curve; and determining the final interface state model based on the simulation model when the transfer characteristic curve meets the preset range of transfer characteristic curve variation. The method described in this invention corrects the problem that existing interface state models only consider a single energy level.

[0013] The present invention also provides an apparatus for constructing an interface state model, comprising:

[0014] The first data processing unit is used to acquire experimental data and obtain a concentration distribution model of interface state defects based on the experimental data.

[0015] The second data processing unit is used to determine the surface recombination rate based on the concentration distribution model and the recombination rate formula set.

[0016] The third data processing unit is used to determine the concentration of ionized interface states based on the recombination rate formula set and the interface state formula set.

[0017] A first modeling unit is used to construct a simulation model based on the surface recombination rate and the concentration of ionized interface states.

[0018] A simulation unit is used to perform simulation experiments on the transistor based on the concentration distribution model and the simulation model to determine the transfer characteristic curve;

[0019] The second modeling unit is used to determine the final interface state model based on the simulation model when the transfer characteristic curve meets the preset range of change of the transfer characteristic curve.

[0020] The interface state model construction device and the interface state model construction method described in this invention have the same advantages over the prior art, and will not be repeated here.

[0021] The present invention also provides a system for constructing an interface state model, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the method for constructing the interface state model.

[0022] The interface state model construction system and the interface state model construction method described in this invention have the same advantages over the prior art, and will not be repeated here.

[0023] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the interface state model construction method.

[0024] The computer-readable storage medium and the method for constructing the interface state model described in this invention have the same advantages over the prior art, and will not be repeated here. Attached Figure Description

[0025] Figure 1 This is a flowchart of the method for constructing the interface state model in an embodiment of the present invention;

[0026] Figure 2 This is a transfer characteristic curve of the simulated NMOS device in an embodiment of the present invention;

[0027] Figure 3 This is a transfer characteristic curve of a simulated PMOS device in an embodiment of the present invention;

[0028] Figure 4 This is a graph showing the experimental and fitting results of the concentration of interface traps as a function of defect energy level in an embodiment of the present invention.

[0029] Figure 5 This is a structural diagram of the interface state model construction device in an embodiment of the present invention. Detailed Implementation

[0030] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0031] Combination Figure 1 As shown, this embodiment of the invention provides a method for constructing an interface state model, including: acquiring experimental data and obtaining a concentration distribution model of interface state defects based on the experimental data;

[0032] Based on the concentration distribution model, the surface recombination rate is determined using the recombination rate formula set.

[0033] The concentration of ionized interface states is determined based on the recombination rate formula set and the interface state formula set.

[0034] A simulation model is constructed based on the surface recombination rate and the concentration of ionized interface states;

[0035] The transistor was simulated using the concentration distribution model and the simulation model to determine the transfer characteristic curve.

[0036] When the transfer characteristic curve meets the preset range of transfer characteristic curve variation, the final interface state model is determined according to the simulation model.

[0037] Specifically, by acquiring experimental data, a concentration distribution model of interface state defects is obtained based on the experimental data; the surface recombination rate is determined based on the concentration distribution model using a set of recombination rate formulas; the concentration of ionized interface states is determined based on the recombination rate formulas and the interface state formulas; a simulation model is constructed based on the surface recombination rate and the concentration of ionized interface states; a simulation experiment is conducted on the transistor based on the concentration distribution model and the simulation model to determine the transfer characteristic curve; when the transfer characteristic curve meets the preset range of transfer characteristic curve variation, the final interface state model is established based on the simulation model.

[0038] To verify the accuracy of the final interface state model, TCAD simulations were performed on N-channel MOS devices and P-channel MOS devices using the model, and the accuracy was judged by the drift direction of the transfer characteristic curve. Compared with the previous model, when using this model, it is not necessary to define the properties of the interface states. The model will automatically exhibit the corresponding properties according to the applied voltage state.

[0039] Figure 2 To simulate the transfer characteristic curves of an NMOS device using this model, from... Figure 2 As can be seen, after adding interface states to the Si-SiO2 of the NMOS device using this model, the transfer characteristic curve shows a positive shift. This indicates that the interface state traps at the Si-SiO2 interface of the NMOS exhibit negative electrical characteristics, which leads to an increase in the turn-on voltage and a positive shift in the curve, consistent with the experimental results.

[0040] Figure 3 To simulate the transfer characteristic curves of a PMOS device using this model, from... Figure 3 As can be seen, after adding interface states to the Si-SiO2 of the PMOS device using this model, the transfer characteristic curve shows a negative shift. This indicates that the interface state traps at the Si-SiO2 interface of the PMOS exhibit positive electrical characteristics, resulting in a reduction in the turn-on voltage and a negative shift in the curve, which is consistent with the experimental results.

[0041] In this embodiment, experimental data is acquired, and a concentration distribution model of interface state defects is obtained based on the experimental data. Based on the above model, the surface recombination rate is determined using a set of recombination rate formulas. The concentration of ionized interface states is determined based on the recombination rate formulas and the interface state formulas. A simulation model is constructed based on the surface recombination rate and the concentration of ionized interface states. A simulation experiment is conducted on the transistor based on the concentration distribution model and the simulation model to determine the transfer characteristic curve. When the transfer characteristic curve meets the preset range of transfer characteristic curve variation, the final interface state model is determined based on the simulation model. The method described in this invention corrects the problem that existing interface state models only consider a single energy level.

[0042] Optionally, obtaining the surface recombination rate based on the concentration distribution model through the recombination rate formula set includes: simultaneously solving the recombination rate formula set and using recombination model theory to obtain the surface recombination rate.

[0043] Specifically, by combining the recombination rate formulas and using SRH theory (Shockely-Read-Hall recombination model), the surface recombination rate introduced by the interface state trap is calculated by integrating between the valence band Ev and the conduction band Ec.

[0044] Optionally, the composite rate formula set includes: a fitting model formula, a surface composite rate formula, and a composite rate formula.

[0045] Specifically, in combination Figure 4 As shown, the square data are experimental data, and the circle data are fitted data; it can be seen that the concentration of interface state traps at each energy level is lower the closer it is to the center of the band gap (0.55 eV), and the overall distribution shows a U-shaped distribution;

[0046] The fitting model formula is:

[0047]

[0048] Where D0 is the defect energy level near the top of the valence band (E t When =0), the concentration of this energy level (1 / cm) 2 eV). Coefficient D0 = 6e11 / cm 2 eV, B1=-6.70027e12, B2=3.23158e13, B3=-8.40621e13, B4=1.22429e14, B5=-9.38074e13, B6=2.94261e13;

[0049] Interface state traps primarily affect the surface recombination rate of the interface, which can be calculated using standard SRH theory. For non-interacting interface state traps in continuous energy levels, the surface recombination rate, surfR, can be obtained by integrating over the band gap.

[0050] The formula for surface recombination rate is:

[0051]

[0052] Where surfR is the recombination rate caused by the interface states, U s (E t The defect energy level is E. t The composite rate at that time;

[0053] The recombination rate can be obtained from the SRH recombination model;

[0054] The formula for the composite rate is:

[0055]

[0056] Among them, U S Composite rate (cm) -3 s -1 p and n are the concentrations of holes and electrons, respectively (cm³). -3 ), n i intrinsic carrier concentration in silicon (cm²) -3 E t For the energy level (eV) of the defect trap, E i Let q be the intrinsic energy level (eV) in silicon, q be the elementary charge (C), and k be the Boltzmann constant (JK). -1 ), T is temperature (K), v n and v p Thermal velocities of electrons and holes (cm / s) -1 ), σ n and σ p The capture cross sections (cm) for electrons and holes, respectively. 2 ).

[0057] Optionally, the interface state defects include donor defects and acceptor defects.

[0058] Optionally, the energy level of the donor defect is in the range of 0-0.55 eV; the energy level of the acceptor defect is in the range of 0.55-1.1 eV.

[0059] Optionally, the interface state formula set includes: a donor defect ionization probability formula, an acceptor defect ionization probability formula, a donor defect emission rate formula for electrons and holes, an acceptor defect emission rate formula for electrons and holes, and a formula for the concentration of ionized defects in the interface state.

[0060] Specifically, F A and F D Formulas for the ionization probability of acceptor and donor defects:

[0061]

[0062]

[0063] Where, σ n and σ p The capture cross sections (cm) for electrons and holes, respectively. -2 p and n are the concentrations of holes and electrons, respectively (cm³). -3 ), where υ is the thermal velocity of the charge carriers;

[0064] e nA and e pA The formula for the emissivity of electrons and holes for acceptor defects is as follows:

[0065]

[0066]

[0067] e nD and e pD The formula for the emissivity of donor-type defects is:

[0068]

[0069]

[0070] Where p and n are the concentrations of holes and electrons, respectively (cm³). -3 ), n i intrinsic carrier concentration in silicon (cm²) -3 E t For the energy level (eV) of the defect trap, E i Let q be the intrinsic energy level (eV) in silicon, q be the elementary charge (C), and k be the Boltzmann constant (JK). -1 ), where T is temperature (K);

[0071] After calculating the probability of a defect being ionized, the concentration of ionized defects can be obtained.

[0072] Formula for the concentration of interface-state defects compared to ionized defects:

[0073]

[0074]

[0075] Optionally, the transistor includes an NMOS transistor and a PMOS transistor.

[0076] Combination Figure 5 As shown, the present invention also provides an apparatus for constructing an interface state model, comprising:

[0077] The first data processing unit is used to acquire experimental data and obtain a concentration distribution model of interface state defects based on the experimental data.

[0078] The second data processing unit is used to determine the surface recombination rate based on the concentration distribution model and the recombination rate formula set.

[0079] The third data processing unit is used to determine the concentration of ionized interface states based on the recombination rate formula set and the interface state formula set.

[0080] A first modeling unit is used to construct a simulation model based on the surface recombination rate and the concentration of ionized interface states.

[0081] A simulation unit is used to perform simulation experiments on the transistor based on the concentration distribution model and the simulation model to obtain a transfer characteristic curve.

[0082] The second modeling unit is used to determine the final interface state model based on the simulation model when the transfer characteristic curve meets the preset range of change of the transfer characteristic curve.

[0083] The interface state model construction device and the interface state model construction method described in this invention have the same advantages over the prior art, and will not be repeated here.

[0084] The present invention also provides a system for constructing an interface state model, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the method for constructing the interface state model.

[0085] The interface state model construction system and the interface state model construction method described in this invention have the same advantages over the prior art, and will not be repeated here.

[0086] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the interface state model construction method.

[0087] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments described above. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM), etc.

[0088] The computer-readable storage medium and the method for constructing the interface state model described in this invention have the same advantages over the prior art, and will not be repeated here.

[0089] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method for constructing an interface state model, characterized in that, include: Acquire experimental data and obtain a concentration distribution model of interface state defects based on the experimental data; wherein, the interface state defects include donor defects and acceptor defects; the energy level of the donor defects is in the range of 0-0.55 eV; the energy level of the acceptor defects is in the range of 0.55-1.1 eV; Based on the concentration distribution model, the surface recombination rate is determined using a set of recombination rate formulas; wherein, the set of recombination rate formulas includes a fitting model formula, a surface recombination rate formula, and a recombination rate formula, and the fitting model formula is: ;in, For the defect level to be close to the top of the valence band At that time, the concentration of this energy level is expressed in units of: , The energy level of the defect trap is expressed in eV, and the coefficient is... , , , ; The concentration of ionized interface states is determined based on the recombination rate formula set and the interface state formula set; the interface state formula set includes: donor defect ionization probability formula.

1. Formula for the ionization probability of acceptor defects The formulas for the emissivity of donor-type defects for electrons and holes, the formulas for the emissivity of acceptor-type defects for electrons and holes, and the formula for the concentration of ionized defects in interface states; among them, the formula for the concentration of ionized defects in interface states is as follows: ; ; A simulation model is constructed based on the surface recombination rate and the concentration of ionized interface states; The transistors are simulated according to the concentration distribution model and the simulation model, wherein the transistors include NMOS transistors and PMOS transistors; specifically, the simulation tests are performed on NMOS transistors and PMOS transistors respectively according to the concentration distribution model and the simulation model to determine the transfer characteristic curves of NMOS transistors and PMOS transistors. When the transfer characteristic curves of the NMOS transistor and the PMOS transistor both meet the corresponding preset transfer characteristic curve variation range, the final interface state model is determined according to the simulation model.

2. The method for constructing the interface state model according to claim 1, characterized in that, The process of obtaining the surface recombination rate based on the concentration distribution model and using the recombination rate formula set includes: combining the recombination rate formula set and using recombination model theory to obtain the surface recombination rate.

3. A device for constructing an interface state model, characterized in that, include: A first data processing unit is used to acquire experimental data and obtain a concentration distribution model of interface state defects based on the experimental data; wherein the interface state defects include donor defects and acceptor defects; the energy level of the donor defects is in the range of 0-0.55 eV; and the energy level of the acceptor defects is in the range of 0.55-1.1 eV. The second data processing unit is used to determine the surface recombination rate based on the concentration distribution model using a set of recombination rate formulas; wherein the set of recombination rate formulas includes a fitting model formula, a surface recombination rate formula, and a recombination rate formula, and the fitting model formula is: ;in, For the defect level to be close to the top of the valence band At that time, the concentration of this energy level is expressed in units of: , The energy level of the defect trap is expressed in eV, and the coefficient is... , , , , ; A third data processing unit is configured to determine the concentration of ionized interface states based on the recombination rate formula set and the interface state formula set; the interface state formula set includes: donor defect ionization probability formula.

1. Formula for the ionization probability of acceptor defects The formulas for the emissivity of donor-type defects for electrons and holes, the formulas for the emissivity of acceptor-type defects for electrons and holes, and the formula for the concentration of ionized defects in interface states; among them, the formula for the concentration of ionized defects in interface states is as follows: ; ; A first modeling unit is used to construct a simulation model based on the surface recombination rate and the concentration of ionized interface states. The simulation unit is used to perform simulation experiments on transistors according to the concentration distribution model and the simulation model, wherein the transistors include NMOS transistors and PMOS transistors; specifically, it includes: performing simulation experiments on NMOS transistors and PMOS transistors respectively according to the concentration distribution model and the simulation model, and determining the transfer characteristic curves of NMOS transistors and PMOS transistors; The second modeling unit is used to determine the final interface state model based on the simulation model when both the transfer characteristic curve of the NMOS transistor and the transfer characteristic curve of the PMOS transistor meet the corresponding preset transfer characteristic curve variation range.

4. A system for constructing an interface state model, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method for constructing the interface state model according to any one of claims 1 to 2.

5. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method for constructing the interface state model according to any one of claims 1 to 2.

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