Simulation method for extracting SPICE model of semiconductor device based on TCAD

Abstract

The invention discloses a simulation method for extracting a semiconductor device SPICE model based on TCAD, and belongs to the technical field of semiconductor devices. TCAD simulation and SPICE model extraction are combined, firstly, a semiconductor device model is established through TCAD simulation software, and a key parameter curve is extracted; fitting a key parameter curve by adopting a least square method, and optimizing the curve to generate an SPICE model card; and finally, performing circuit simulation by using the SPICE model card as a library file in a circuit-level simulation tool, and verifying the application of the SPICE model card in a complex circuit. According to the method, complex physical effects are reflected by extracting high-precision physical model parameters of the device, fusion of device simulation and circuit simulation is achieved, the method has the advantages of being high in precision, flexible, low in cost and the like, the method can be used for evaluation of different process nodes and exploration of novel devices, research and development cost is reduced, the development period is shortened, and the method is suitable for popularization and application. And effective support is provided for innovative design.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor devices, and in particular to a simulation method for extracting a SPICE model of a semiconductor device based on TCAD. Background Art

[0002] With the rapid development of semiconductor technology, device size is gradually reduced, process nodes are constantly improving, and the complexity of device and circuit design has increased significantly. Traditional device modeling and simulation methods can no longer meet the current high-precision and high-efficiency design requirements. In the modern semiconductor design process, device simulation and circuit simulation are two key links. In order to achieve efficient operation of devices in circuits, circuit design usually relies on SPICE (Simulation Program with Integrated Circuit Emphasis) models for simulation.

[0003] SPICE is a standard tool for simulating electronic circuits, which can accurately predict the static and dynamic behavior of circuits. However, the quality of SPICE models directly depends on the accuracy of device parameters, and traditional SPICE model extraction methods often rely on physical experimental data or empirical formulas. This method requires a large number of tests on devices in the laboratory to obtain the electrical characteristic curves of the devices, and then generate the corresponding SPICE models by fitting these experimental data. However, as semiconductor processes enter the nanoscale, device characteristics become more and more complex, and the acquisition and fitting process of experimental data becomes more difficult, especially in the face of new devices and process nodes.

[0004] TCAD (Technology Computer-Aided Design Semiconductor Process and Device Simulation) technology is a tool used to simulate and analyze the physical characteristics of semiconductor devices. By solving a series of physical equations (such as Poisson's equation, continuity equation, etc.), it can accurately simulate the electrical, thermal and mechanical properties inside the device, thereby deeply understanding the physical characteristics of the device. Unlike traditional experimental measurements, TCAD simulation can provide detailed device characteristic data without the need for actual samples, and has the advantages of high accuracy, flexibility and low cost. However, TCAD simulation is often limited to the device level and cannot be directly applied to circuit simulation. Therefore, converting TCAD simulation results into SPICE models suitable for circuit design has become an important topic in the current semiconductor design process.

[0005] In order to achieve the integration from device simulation to circuit simulation, a method is needed to extract device SPICE models from TCAD simulation, which can not only ensure the high accuracy of the model, but also be flexible to adapt to different process nodes and device structures, while reducing the cost of simulation and experiments. Summary of the invention

[0006] The problem to be solved by the present invention is to provide a simulation method for extracting SPICE models of semiconductor devices based on TCAD, combining TCAD simulation with SPICE model extraction to adapt to the characteristics of various new devices and advanced process nodes, reduce R&D costs, shorten development cycles, and improve design efficiency.

[0007] The present invention adopts the following technical solution: a simulation method for extracting a SPICE model of a semiconductor device based on TCAD, comprising the following steps:

[0008] Step S1, establishing a device electrical model: using semiconductor process and device simulation tools to model and simulate the device, defining a physical model for electrical simulation of the semiconductor device, and obtaining key characteristic curves of the device;

[0009] Step S2, parameter fitting: select a suitable SPICE model according to device characteristics. Different SPICE models are suitable for different process nodes and device types. Perform SPICE model parameter extraction and fitting;

[0010] Step S3, verification and tuning: comparing the extracted SPICE model with the simulation results of the device, and adjusting and optimizing the SPICE model parameters to make the SPICE model consistent with the actual behavior of the device at each operating point;

[0011] Step S4, generating a SPICE model file: after the SPICE model parameter fitting is completed and tuned, the parameters are written into the SPICE model file for use by the circuit simulator;

[0012] Step S5, verifying the SPICE model: using the verified SPICE model in a circuit level simulation tool to perform circuit simulation to verify the application of the SPICE model in complex circuits.

[0013] Preferably, in step S1, the device is a semiconductor device of different types and process nodes; TCAD software is used to construct an electrical model of the semiconductor device, form a three-dimensional structural axial section view of the semiconductor device, and extract key characteristic curves of the semiconductor device.

[0014] Furthermore, the key characteristic curves include: a transfer characteristic curve of a device and an output characteristic curve of a device.

[0015] Preferably, in step S2, SPICE model parameter extraction and fitting are performed, including the following sub-steps:

[0016] Step S2.1, run TCAD simulation software to generate a device netlist file, including: device attributes and node naming;

[0017] Step S2.2, establishing a device model card according to the physical parameters of the built device, including: selecting a physical model, doping concentration, gate oxide thickness, and junction depth;

[0018] Step S2.3, optimize the device physical model and use the least squares method to fit the key characteristic curve of the device.

[0019] Step S2.4, running the simulation so that the SPICE model accurately reflects the physical simulation results;

[0020] Step S2.5: Generate a SPICE model file after verification and optimization, and export the device SPICE model card.

[0021] Preferably, in step S4, the SPICE model file describes the established SPICE model by means of physical parameters, including: device name, device type, SPICE model card, doping concentration, junction depth and other physical parameters.

[0022] Preferably, in step S5, the circuit level simulation tool includes: Hspice software and Spectre software.

[0023] Furthermore, the SPICE model card is verified by Hspice software, circuit simulation is performed, and the SPICE model file is imported into the Hspice software as a library file to verify the application of the SPICE model.

[0024] Compared with the prior art, the present invention adopts the above technical solution and has the following technical effects:

[0025] 1. The simulation method of the present invention establishes a semiconductor device model through TCAD simulation software, extracts key parameter curves, uses the least squares method to fit the key parameter curves, generates a SPICE model card after optimizing the curves, and uses the SPICE model card as a library file in a circuit-level simulation tool to perform circuit simulation, verifying its application in complex circuits, thereby solving the problem that traditional SPICE models are difficult to meet the needs of high-precision circuit simulation due to the lack of accurate description of complex physical effects.

[0026] 2. The method of extracting device SPICE models based on TCAD in the present invention realizes the integration of device simulation and circuit simulation, and has the characteristics of high precision, flexibility and low cost. The simulation method can also assist in judging the feasibility of device design and performance optimization to shorten the research and development cycle. At the same time, the method can be used for the evaluation of different process nodes and the exploration of new devices, providing support for innovative design. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1The present invention is a flow chart of a method for extracting a device SPICE model based on TCAD;

[0028] Figure 2 This is a structural diagram of a semiconductor device according to an embodiment of the present invention;

[0029] Figure 3 The electrical characteristic curve diagram of the NMOS tube according to the embodiment of the present invention;

[0030] Figure 4 This is a SPICE parameter extraction and fitting flow chart of an embodiment of the present invention;

[0031] Figure 5 Generate a SPICE model partial file for the embodiment of the present invention;

[0032] Figure 6 This is a SPICE model verification diagram for an embodiment of the present invention. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the application is further elaborated in detail below in conjunction with the accompanying drawings. The described embodiments are only a part of the embodiments involved in the present invention. All non-innovative embodiments of other researchers in the field on this embodiment belong to the protection scope of the present invention. At the same time, for the step numbering in the embodiment of the present invention, it is only set for the convenience of explanation, and the order between the steps is not limited in any way. The execution order of each step in the embodiment can be adaptively adjusted according to the understanding of those skilled in the art.

[0034] In one embodiment of the present invention, a simulation method for extracting a SPICE model of a semiconductor device based on TCAD is provided. Figure 1 As shown, the following steps are included:

[0035] Step 1: Establish device electrical model: For semiconductor devices of different types and process nodes, use semiconductor process and device simulation tools to model and simulate the devices, define the physical model of semiconductor device electrical simulation, and obtain the key characteristic curves of the devices.

[0036] Step 2: Parameter fitting: Select a suitable SPICE model based on the characteristics of the simulated device. Different SPICE models are suitable for different process nodes and device types.

[0037] Step 3: Verification and tuning: Compare the extracted SPICE model with the device simulation results to ensure that the model accurately reflects the physical simulation results. By repeatedly adjusting and optimizing parameters, ensure that the SPICE model is consistent with the actual behavior of the device at various operating points.

[0038] Step 4: Generate SPICE model file: After the SPICE model parameters are fitted and tuned, write these parameters into the SPICE model file for use by the circuit simulator.

[0039] Step 5. Verify the SPICE model: Use the SPICE model to perform circuit simulation in circuit-level simulation tools (such as HSPICE, Spectre, etc.) to verify its application in complex circuits.

[0040] This embodiment uses TCAD software to establish a semiconductor device model and Hspice software to verify the SPICE model card. The simulation steps are as follows:

[0041] First, the electrical model of the semiconductor device is constructed using TCAD;

[0042] Secondly, extract the key characteristic curve of the semiconductor device, use the least square method to fit the curve, and generate the SPICE model file after verification and optimization;

[0043] Finally, the SPICE model file is imported into the Hspice software as a library file to verify the application of the SPICE model.

[0044] Specifically, this embodiment establishes a 28nm process MOSFET three-dimensional structure zy axis cross-sectional diagram, referring to Figure 2 As shown in the figure. The doping concentrations of the main regions in the NMOS device are substrate doping concentration 3.0×10 18 cm -3 , source doping concentration 4.0×10 20 cm -3 , drain doping concentration 4.0×10 20 cm -3 .

[0045] The electrical characteristics simulation of the device refers to Figure 3 As shown. The electrical characteristic curve of the 28nm process MOSFET device is obtained. Figure 3 (a) is the transfer characteristic curve of the MOSFET device when the drain voltage is 0.05V; Figure 3 (b) in the figure is the output characteristic curve of the MOSFET device when the gate voltage is 1V.

[0046] Further, the SPICE parameter extraction and fitting process of this embodiment refers to Figure 4 shown.

[0047] First, run the TCAD simulation tool to generate a device netlist file based on the built device, which includes device attributes and node naming.

[0048] Secondly, a device model card is established based on the physical parameters of the built device, including the selection of physical model, doping concentration, gate oxide thickness and junction depth.

[0049] Finally, optimize the device physical model and select the least squares fitting method as the optimization method. After the simulation is run, export the device model card.

[0050] The SPICE model part files generated in this embodiment are as follows: Figure 5 As shown in the figure, the file describes the built model in detail through physical parameters, including device name, device type, SPICE model card, doping concentration, junction depth and other physical parameters.

[0051] Furthermore, this embodiment uses the circuit simulation software Hspice to verify the SPICE model card, and imports the extracted SPICE model card into the Hspice software as a simulation library file. The SPICE model verification result is referenced. Figure 6 As shown, the result graph after running the simulation is the HSPICE curve in the figure, and the simulation results are consistent with the trend of the TCAD simulation results.

[0052] It can be seen that the method for extracting device SPICE models based on TCAD provided by the present invention realizes the integration of device-level and circuit-level simulation methods; and based on this simulation method, the accuracy and flexibility of the device model can be improved; it provides a high-precision simulation method for the simulation of new device types, advanced process nodes, and large-scale integrated circuits. It solves the problem that traditional simulation methods can only simulate a single module, and makes up for the current research deficiencies in this area.

[0053] According to the method of extracting device SPICE models based on TCAD of the present invention, circuit-level simulation models of different sizes can be established for circuit design simulation, so that the device model in the circuit simulation is closer to the actual process, ensuring the accuracy and reliability of the circuit simulation results. The method enables designers to optimize device characteristics at the device level, thereby improving the overall performance of the circuit, such as power consumption, speed, and stability. At the same time, through accurate simulation, the need for physical experiments and multiple design iterations is reduced, thereby shortening the circuit design cycle and reducing the cost of physical sample production and testing. This method can help explore new circuit architectures, estimate circuit performance in advance, and promote technological innovation.

[0054] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A simulation method for extracting a SPICE model of a semiconductor device based on TCAD, characterized in that: The steps include: Step S1, establishing a device electrical model: using semiconductor process and device simulation tools to model and simulate the device, defining a physical model for electrical simulation of the semiconductor device, and obtaining key characteristic curves of the device; Step S2, parameter fitting: select a suitable SPICE model according to device characteristics. Different SPICE models are suitable for different process nodes and device types. Perform SPICE model parameter extraction and fitting; Step S3, verification and tuning: comparing the extracted SPICE model with the simulation results of the device, and adjusting and optimizing the SPICE model parameters to make the SPICE model consistent with the actual behavior of the device at each operating point; Step S4, generating a SPICE model file: after the SPICE model parameter fitting is completed and tuned, the parameters are written into the SPICE model file for use by the circuit simulator; Step S5, verifying the SPICE model: using the verified SPICE model in a circuit level simulation tool to perform circuit simulation to verify the application of the SPICE model in complex circuits.

2. The simulation method for extracting a semiconductor device SPICE model based on TCAD according to claim 1, characterized in that: In step S1, the device is a semiconductor device of different types and process nodes; TCAD software is used to construct an electrical model of the semiconductor device, form a three-dimensional structural axial section diagram of the semiconductor device, and extract key characteristic curves of the semiconductor device.

3. The simulation method for extracting a semiconductor device SPICE model based on TCAD according to claim 2, characterized in that: In step S1, the key characteristic curves include: a transfer characteristic curve of the device and an output characteristic curve of the device.

4. The simulation method for extracting a semiconductor device SPICE model based on TCAD according to claim 2, characterized in that: In step S2, SPICE model parameter extraction and fitting are performed, including the following sub-steps: Step S2.1, run TCAD simulation software to generate a device netlist file, including: device attributes and node naming; Step S2.2, establishing a device model card according to the physical parameters of the built device, including: selecting a physical model, doping concentration, gate oxide thickness, and junction depth; Step S2.3, optimizing the device physical model, and fitting the key characteristic curve of the device using the least square method; Step S2.4, running the simulation so that the SPICE model accurately reflects the physical simulation results; Step S2.5: Generate a SPICE model file after verification and optimization, and export the device SPICE model card.

5. The simulation method for extracting a semiconductor device SPICE model based on TCAD according to claim 1, characterized in that: In step S4, the SPICE model file describes the established SPICE model in the form of physical parameters, and the physical parameters include: device name, device type, SPICE model card, doping concentration, and junction depth.

6. The simulation method for extracting a semiconductor device SPICE model based on TCAD according to claim 2, characterized in that: In step S5, the circuit level simulation tool is Hspice software; circuit simulation is performed, the SPICE model card is verified using Hspice software, the SPICE model file is imported into the Hspice software as a library file, and the application of the SPICE model is verified.

7. The simulation method for extracting a semiconductor device SPICE model based on TCAD according to claim 2, characterized in that: In step S5, the circuit level simulation tool further includes: Spectre software.

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