Method for optimizing adaptive oxidation condition of silicon oxide film, computing system and computer equipment
By employing first-principles calculations and elementary molecular dynamics methods, the problem of large calculation errors in the oxidation conditions of silicon oxide thin films in existing technologies has been solved, enabling more accurate prediction of oxidation conditions and improving calculation precision and reliability.
Patent Information
- Application Number
- CN202510912495.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-02
- Publication Date
- 2025-11-21
AI Technical Summary
In the prior art, first-principles calculations, with limited computing resources, are difficult to accurately describe the migration process of hydrogen atoms in silicon, resulting in large calculation errors in the oxidation conditions of silicon oxide thin films and making it impossible to effectively predict more suitable oxidation conditions.
First-principles calculations based on density functional theory, combined with molecular dynamics, were used to calculate the bond lengths of Si-O and Si-H bonds by expanding the Si unit cell, adding a vacuum layer and interstitial H and O layers, and obtaining potential energy diagrams to accurately predict the migration routes of hydrogen and oxygen in silicon.
It provides more accurate atomic migration directions, offering theoretical support for subsequent computational simulations and improving the accuracy and reliability of calculations on silicon oxide thin film oxidation conditions.
Smart Images
Figure CN120998321A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical fields of materials science and computational chemistry, and in particular to a method, computational system and computer device for optimizing silicon oxide thin films to adapt to oxidation conditions. Background Technology
[0002] Silicon oxide thin films are widely used dielectric layer films in CMOS processes. In deep submicron processes, the gate oxide dielectric layer in the gate structure is usually prepared by thermal oxidation, which is specifically divided into wet oxidation, dry oxidation and water vapor oxidation reaction.
[0003] Among them, silica films grown by dry oxidation exhibit a dense, dry structure, good uniformity and repeatability, strong masking ability, good passivation effect, and good film uniformity. However, the time-dependent breakdown (TDDB) characteristic of the oxide layer formed by dry oxidation is poor. Silica films grown by wet oxidation have slightly lower density than those grown by dry oxidation. After the oxidation reaction, the silicon wafer surface has more dislocations and corrosion pits. Its masking ability and passivation effect are generally average, and the film uniformity is relatively poor. However, it has the advantage of a fast growth rate, relatively better TDDB, and stable film quality. Silica films grown by water vapor oxidation have a loose structure, with spots and defects on the surface, high water content, poor masking ability for impurities, and good film uniformity. The difference between wet and dry oxidation lies in whether hydrogen atoms (H) participate in the oxidation process; therefore, understanding how hydrogen atoms promote the oxidation process is crucial.
[0004] Currently, calculations using first principles can accurately describe processes at the atomic level. By accurately understanding the reaction processes at the atomic level, we can further understand the reasons for the differences between wet and dry oxidation, and thus predict more suitable oxidation conditions.
[0005] However, the extremely high computational demands of first-principles calculations lead to a sharp increase in computational costs as the number of samples increases. Therefore, current first-principles calculations of the migration process of H and O in Si are based on chemical intuition and are generally subject to significant errors. Thus, how to efficiently sample and calculate the specific migration processes of H and O in Si and the microscopic structures between atoms under limited computational resources, and subsequently deduce the more suitable oxidation conditions for silicon oxide films, has become a pressing problem that needs to be solved. Summary of the Invention
[0006] The purpose of this application is to provide a method, computing system, and computer device for optimizing the oxidation conditions of silicon oxide thin films to solve the above-mentioned problems.
[0007] Based on this, this application provides a method for optimizing the oxidation conditions of silicon oxide thin films, comprising:
[0008] Step 1: Obtain the Si unit cell model information and perform first-principles relaxation calculations to obtain the structural information of the stable configuration of the Si unit cell;
[0009] Step 2: Expand the Si unit cell based on the structural information of the stable Si unit cell configuration to obtain the structural information of the Si supercell;
[0010] Step 3: Perform first-principles relaxation calculations on the structural information of the Si supercell to obtain the structural information of the stable configuration of the Si supercell;
[0011] Step 4: Based on the structural information of the stable configuration of the Si supercell, add a vacuum layer to the Si supercell and add H to the dangling bonds on the surface of Si atoms to obtain the structural information of the Si supercell with a vacuum layer.
[0012] Step 5: Perform first-principles relaxation calculations on the structural information of the Si supercell with the vacuum layer to obtain the structural information of the stable configuration of the Si supercell with the vacuum layer;
[0013] Step 6: Construct a Si supercell structure with gaps H and O based on the structural information of the stable configuration of the Si supercell with vacuum layer, and obtain the structural information of the Si supercell with gaps H and O;
[0014] Step 7: Perform first-principles relaxation calculations on the Si supercell structure information with gaps H and O to obtain the structural information of the stable configuration of the Si supercell with gaps H and O;
[0015] Step 8: Set the bond length range of Si-O and Si-H bonds, and perform first-principles molecular dynamics calculations within the bond length range of Si-O and Si-H bonds based on the structural information of the stable configuration of the Si supercell with interstitial H and interstitial O. Statistically analyze the results and obtain the potential energy diagrams of interstitial H and interstitial O.
[0016] In one embodiment, step one includes:
[0017] Obtain the crystal structure file of Si from an open-source materials database;
[0018] Extract Si unit cell model information that can be used for first-principles calculation software from the crystal structure file of Si;
[0019] The cutoff energy is set based on the maximum plane wave cutoff energy information of all elements in the pseudopotential file, and XYZ is selected as the system periodic boundary condition. The D3 system dispersion correction method is selected, and the first-principles structural relaxation calculation is performed on the Si unit cell model information to obtain the system energy corresponding to the Si unit cell configuration. The system energy includes the structural information of the stable configuration of the Si unit cell.
[0020] In one embodiment, step two includes:
[0021] The structural information of the stable configuration of the Si unit cell is read and the lattice vector of the Si crystal is transformed, changing the original 1×1×1 lattice vector to 2×2×1, to obtain the crystal structure file of the Si supercell.
[0022] Structural information of the Si supercell that can be used for first-principles calculation software is extracted from the crystal structure file of the Si supercell.
[0023] In one embodiment, in step four, a 15 Å vacuum layer is added to the Si supercell.
[0024] In one embodiment, step six includes:
[0025] Read the structural information of the stable configuration of the Si supercell with vacuum layer, and construct the Si supercell structure with gaps H and O to obtain the crystal structure file of the Si supercell structure with gaps H and O;
[0026] Structural information of the Si supercell with gaps H and O, which can be used in first-principles calculation software, is extracted from the crystal structure file of the Si supercell structure with gaps H and O.
[0027] In one embodiment, the first-principles relaxation calculation process in steps three, five, and seven includes:
[0028] Select the same cutoff energy as in step one, select XYZ as the system periodic boundary condition, select the D3 system dispersion correction method, perform first-principles relaxation calculations on the target parameters, and obtain the structural information of the corresponding stable configuration.
[0029] In one embodiment, during the first-principles relaxation calculation of the structural information of the Si supercell with gaps H and O, the bottom two layers of atoms on the Z-axis are fixed to simulate the Si substrate.
[0030] In one embodiment, the bond lengths of the Si-O and Si-H bonds range from 0 to 0.3 nm.
[0031] Another embodiment discloses a computational system for optimizing the oxidation conditions of silicon oxide thin films, comprising:
[0032] The model building module is used to construct Si primitive cells, Si supercells, Si supercells with vacuum layers, and Si supercells with gaps H and O, and correspondingly generate Si primitive cell model information, Si supercell structural information, Si supercell structural information with vacuum layers, and Si supercell structural information with gaps H and O.
[0033] The first-principles relaxation calculation module, connected to the model building module, receives the output of the model building module and generates structural information of the Si primitive cell stable configuration, the Si supercell stable configuration, the Si supercell stable configuration with a vacuum layer, and the Si supercell stable configuration with gaps H and O. Simultaneously, it outputs the structural information of the Si primitive cell stable configuration, the Si supercell stable configuration, and the Si supercell stable configuration with a vacuum layer to the model building module.
[0034] The first-principles molecular dynamics calculation and statistics module, connected to the first-principles relaxation calculation module, is used to receive the structural information of the stable configuration of the Si supercell with gap H and gap O, and to perform first-principles molecular dynamics calculations within a preset range of Si-O and Si-H bond lengths based on the structural information of the stable configuration of the Si supercell with gap H and gap O, and to statistically analyze the results to obtain the potential energy diagrams of gap H and gap O.
[0035] Another embodiment discloses a computer device including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method for optimizing the oxidation conditions of silicon oxide thin films as described in any of the above embodiments.
[0036] This invention employs first-principles calculations based on density functional theory, using molecular dynamics to accurately obtain the movement of interstitial H and O atoms within the Si supercell as the system energy increases, further inferring the distribution of the potential energy surface. As the overall system energy increases, H and O gradually overcome the binding force of Si and move within a certain spatial range. Statistical analysis of the movement positions of H and O within the supercell yields the potential energy surface near H and O. This potential energy surface allows for accurate prediction of the most probable migration routes of H and O within Si. The method, utilizing molecular dynamics, obtains the potential energy surface around atoms, more accurately predicting the most probable migration routes of H and O within Si. Compared to relying on personal chemical intuition, this method provides more accurate atomic migration directions, offering strong theoretical support for subsequent computational simulations and ultimately more accurately predicting the suitable oxidation conditions for silicon oxide films. Attached Figure Description
[0037] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0038] Figure 1 A flowchart of a method for optimizing oxidation conditions for silicon oxide thin films is provided as an embodiment of this application;
[0039] Figure 2 A potential energy diagram provided for an embodiment of this application when gaps H and O coexist in Si;
[0040] Figure 3 This is a schematic diagram of a computational system for optimizing the oxidation conditions of silicon oxide thin films, provided as an embodiment of this application. Detailed Implementation
[0041] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.
[0042] This invention discloses a method for optimizing the oxidation conditions of silicon oxide thin films, such as... Figure 1 As shown, it includes:
[0043] Step 1: Obtain the Si unit cell model information and perform first-principles relaxation calculations to obtain the structural information of the stable configuration of the Si unit cell;
[0044] Step 2: Expand the Si unit cell based on the structural information of the stable Si unit cell configuration to obtain the structural information of the Si supercell;
[0045] Step 3: Perform first-principles relaxation calculations on the structural information of the Si supercell to obtain the structural information of the stable configuration of the Si supercell;
[0046] Step 4: Based on the structural information of the stable configuration of the Si supercell, add a vacuum layer to the Si supercell and add H to the dangling bonds on the surface of Si atoms to obtain the structural information of the Si supercell with a vacuum layer.
[0047] Step 5: Perform first-principles relaxation calculations on the structural information of the Si supercell with the vacuum layer to obtain the structural information of the stable configuration of the Si supercell with the vacuum layer;
[0048] Step 6: Construct a Si supercell structure with gaps H and O based on the structural information of the stable configuration of the Si supercell with vacuum layer, and obtain the structural information of the Si supercell with gaps H and O;
[0049] Step 7: Perform first-principles relaxation calculations on the Si supercell structure information with gaps H and O to obtain the structural information of the stable configuration of the Si supercell with gaps H and O;
[0050] Step 8: Set the bond length range of Si-O and Si-H bonds, and perform first-principles molecular dynamics calculations within the bond length range of Si-O and Si-H bonds based on the structural information of the stable configuration of the Si supercell with interstitial H and interstitial O. Statistically analyze the results and obtain the potential energy diagrams of interstitial H and interstitial O.
[0051] In this step, the bond lengths of Si-O and Si-H bonds are restricted by setting the bond length range of Si-O and Si-H bonds. The purpose of this is to ensure that the atoms move within the desired range and to ensure that the collected data are the relevant data of the potential energy surface of O and H in Si.
[0052] First-principles calculations refer to quantum computations performed using only basic data without any empirical parameters. By solving the Kohn-Sham equations, molecular structure and the properties of matter are derived. This method boasts high accuracy and reliability and has wide applications in materials science, computational chemistry, and other fields. Structure design and optimization are performed using atomic coordinates and pseudopotential information of each element input from the structural model, followed by molecular dynamics simulations.
[0053] First-principles molecular dynamics is a theoretical approach for studying the mechanical precession processes of systems coupled with atomic nuclei. This method acts as a "microscope" for observing chemical reactions at the atomic and molecular scale. By applying first-principles molecular dynamics, we can understand microscopic dynamic processes from an atomic perspective, thus gaining a fundamental understanding. Unlike traditional molecular dynamics, first-principles molecular dynamics breaks down the motion of nucleus-electron coupled systems into electronic structure and molecular dynamics. It uses methods such as density functional theory to calculate the electronic structure under specific atomic nucleus configurations, thus obtaining more accurate atomic-scale processes.
[0054] Metadynamics is a type of enhanced sampling technique that promotes sampling by introducing additional bias potentials (or forces) acting on selected degrees of freedom.
[0055] First-principles molecular dynamics enhances sampling on the basis of first-principles molecular dynamics. Specifically, it changes the overall energy every certain period of time. The change in overall energy leads to a change in the tendency of atomic motion. By statistically analyzing the change in the tendency of selected atoms to motion, the potential energy surface around the selected atoms can be obtained.
[0056] This embodiment employs first-principles calculations based on density functional theory to accurately capture the movement of interstitial H and O atoms within the Si supercell as the system energy increases, further inferring the distribution of the potential energy surface. As the overall system energy increases, H and O gradually overcome the binding force of Si and move within a certain spatial range. Statistical analysis of the movement positions of H and O within the supercell yields the potential energy surface near H and O. This potential energy surface allows for accurate prediction of the most probable migration routes of H and O within Si. The entire method utilizes molecular dynamics calculations to obtain the potential energy surface around atoms, more accurately predicting the most probable migration routes of H and O within Si. Compared to relying on personal chemical intuition, this method provides more accurate atomic migration directions, offering strong theoretical support for subsequent computational simulations and thus more accurately predicting the suitable oxidation conditions for silicon oxide films.
[0057] Another embodiment discloses a method for optimizing the oxidation conditions of silicon oxide thin films, including:
[0058] Step 1: Obtain Si unit cell model information and perform first-principles relaxation calculations to obtain structural information of the stable configuration of the Si unit cell. Specifically, this includes:
[0059] Obtain the crystal structure file of Si from an open-source materials database;
[0060] Extract Si unit cell model information that can be used for first-principles calculation software from the crystal structure file of Si;
[0061] The cutoff energy is set based on the maximum plane wave cutoff energy information of all elements in the pseudopotential file, and XYZ is selected as the system periodic boundary condition. The D3 system dispersion correction method is selected, and the first-principles structural relaxation calculation is performed on the Si unit cell model information to obtain the system energy corresponding to the Si unit cell configuration. The system energy includes the structural information of the stable configuration of the Si unit cell.
[0062] The method for setting the cutoff energy mainly involves gradually increasing the cutoff energy while observing the change in the total energy of the system. When the change in total energy with the increase of the cutoff energy is lower than the set threshold, the cutoff energy is considered to have converged, which is the cutoff energy set in this method.
[0063] Step 2: Expand the Si unit cell based on the structural information of the stable Si unit cell configuration to obtain the structural information of the Si supercell. Specifically, this includes:
[0064] The structural information of the stable configuration of the Si unit cell is read and the lattice vector of the Si crystal is transformed, changing the original 1×1×1 lattice vector to 2×2×1, to obtain the crystal structure file of the Si supercell.
[0065] Structural information of the Si supercell that can be used for first-principles calculation software is extracted from the crystal structure file of the Si supercell.
[0066] This step is to eliminate the mutual influence between H and O in adjacent unit cells caused by the periodic structure.
[0067] Step 3: Perform first-principles relaxation calculations on the structural information of the Si supercell to obtain the structural information of the stable configuration of the Si supercell. Specifically, this includes:
[0068] Select the same cutoff energy as in step one, select XYZ as the system periodic boundary condition, select the D3 system dispersion correction method, perform first-principles structural relaxation calculations on the structural information of the Si supercell, and obtain the system energy corresponding to the Si supercell configuration. The system energy includes the structural information of the stable configuration of the Si supercell.
[0069] Step 4: Based on the structural information of the stable configuration of the Si supercell, a vacuum layer is added to the Si supercell. H atoms are added to the dangling bonds on the surface of Si atoms to obtain the structural information of the Si supercell with a vacuum layer. Specifically, a 15 Å vacuum layer is added to the Si supercell.
[0070] This step is to better simulate the real oxidation process. Specifically, because the addition of the vacuum layer creates a surface, the Si atoms on the surface will form unsaturated dangling bonds, which do not exist in reality. Therefore, H atoms need to be added to the dangling bonds to ensure that there are no empty dangling bonds.
[0071] Step 5: Perform first-principles relaxation calculations on the structural information of the Si supercell with the vacuum layer to obtain the structural information of the stable configuration of the Si supercell with the vacuum layer.
[0072] Specifically, the same cutoff energy as in step one is selected, XYZ is selected as the system periodic boundary condition, and the D3 system dispersion correction method is selected. First-principles structural relaxation calculations are performed on the structural information of the Si supercell with a vacuum layer to obtain the system energy corresponding to the Si supercell configuration with a vacuum layer. The system energy includes the structural information of the stable configuration of the Si supercell with a vacuum layer.
[0073] Step 6: Construct a Si supercell structure with gaps H and O based on the structural information of the stable configuration of the Si supercell with vacuum layer, and obtain the structural information of the Si supercell with gaps H and O.
[0074] Specifically, it includes:
[0075] Read the structural information of the stable configuration of the Si supercell with vacuum layer and construct the Si supercell structure with gaps H and O to obtain the crystal structure file of the Si supercell with gaps H and O;
[0076] Structural information of the Si supercell with gaps H and O that can be used in first-principles calculation software is extracted from the crystal structure file of the Si supercell with gaps H and O.
[0077] Step 7: Perform first-principles relaxation calculations on the structural information of the Si supercell with gaps H and O to obtain the structural information of the stable configuration of the Si supercell with gaps H and O.
[0078] Specifically, the same cutoff energy as in step one is selected, XYZ is selected as the system periodic boundary condition, and the D3 system dispersion correction method is selected to perform first-principles relaxation calculations on the structural information of the Si supercell with gaps H and O to obtain the system energy corresponding to the Si supercell with gaps H and O. The system energy includes the structural information of the stable configuration of the Si supercell with gaps H and O.
[0079] In the process of performing first-principles relaxation calculations on the Si supercell structure information with gaps H and O, the bottom two layers of atoms on the Z-axis are fixed to simulate the Si substrate.
[0080] Step 8: Set the bond length range of Si-O and Si-H bonds, and perform first-principles molecular dynamics calculations within the bond length range of Si-O and Si-H bonds based on the structural information of the stable configuration of the Si supercell with interstitial H and interstitial O. Statistically analyze the results and obtain the potential energy diagrams of interstitial H and interstitial O.
[0081] The bond lengths of the Si-O and Si-H bonds range from 0 to 0.3 nm. In the first-principles molecular dynamics calculations, the sampling energy change step size is 0.03 eV, the change frequency is 100, the total step size is 10,000 steps, and the duration of each step is 1 femtosecond.
[0082] In summary, the first-principles relaxation calculation process in steps three, five, and seven includes:
[0083] Select the same cutoff energy as in step one, select XYZ as the system periodic boundary condition, select the D3 system dispersion correction method, perform first-principles relaxation calculations on the target parameters, and obtain the structural information of the corresponding stable configuration.
[0084] Another embodiment of the present invention discloses another method for optimizing the oxidation conditions of silicon oxide thin films, comprising:
[0085] Step 1: Obtain the Si unit cell model information and perform first-principles relaxation calculations to obtain the structural information of the stable configuration of the Si unit cell. The specific method is as follows:
[0086] Obtain the crystal structure file (.cif) of Si from the open-source Materials Project database, which includes the lattice shape, lattice constant, and atomic coordinates.
[0087] The Si unit cell model information that can be used for first-principles calculations is extracted from the Si crystal structure file. Specifically, the structural information in the Si crystal structure file (.cif) is read using the quantum chemical wavefunction analysis program (Multiwfn) and used to create an input file (.inp file) for the first-principles calculation software (CP2K) to optimize the structure, thus obtaining the Si unit cell model information that can be used for first-principles calculations.
[0088] The cutoff energy is set based on the maximum plane wave cutoff energy information of all elements in the pseudopotential file (BASIS_MOLOPT), and XYZ is selected as the system periodic boundary condition. The D3 system dispersion correction method is selected, and first-principles structural relaxation calculations are performed on the Si unit cell model information to obtain the system energy corresponding to the Si unit cell configuration. The system energy includes the structural information of the stable configuration of the Si unit cell, such as lattice parameters, atomic coordinates, and system energy.
[0089] Step 2: Expand the Si unit cell based on the structural information of the stable Si unit cell configuration to obtain the structural information of the Si supercell. The specific method is as follows:
[0090] The structural information of the stable configuration of the Si unit cell is read, and the lattice vector of the Si crystal is transformed, changing the original 1×1×1 lattice vector to 2×2×1, thus obtaining the crystal structure file of the Si supercell. Specifically, the structural information of the stable configuration of the Si unit cell is read using Vesta software, and the transform function in the Edit Data directory of Vesta software is selected to change the original 1×1×1 lattice vector to 2×2×1, thereby obtaining the Si supercell and its crystal structure file.
[0091] The structural information of the Si supercell that can be used in first-principles calculation software is extracted from the crystal structure file of the Si supercell. Specifically, the structural information in the crystal structure file of the Si supercell is read using quantum chemical wavefunction analysis software and used as an input file for the first-principles calculation software (CP2K) to optimize the structure, thus obtaining the structural information of the Si supercell that can be used in the first-principles calculation software.
[0092] Step 3: Perform first-principles relaxation calculations on the structural information of the Si supercell to obtain the structural information of the stable configuration of the Si supercell. Specifically, this includes:
[0093] Select the same cutoff energy as in step one, select XYZ as the system periodic boundary condition, select the D3 system dispersion correction method, perform first-principles structural relaxation calculations on the structural information of the Si supercell, and obtain the system energy corresponding to the Si supercell configuration. The system energy includes the structural information of the stable configuration of the Si supercell, such as lattice parameters, atomic coordinates and system energy.
[0094] Step 4: Based on the structural information of the stable configuration of the Si supercell, add a vacuum layer to the Si supercell and add H to the dangling bonds on the surface of Si atoms to obtain the structural information of the Si supercell with a vacuum layer.
[0095] Specifically, to better simulate the real oxidation process, a vacuum layer needs to be added to the stable Si supercell. Therefore, text reading software was used to read the structural information of the stable Si supercell configuration, and the Z-axis length of the supercell was modified to create a 15 Å vacuum layer. That is, the side with the vacuum layer is used to simulate a real surface. However, since adding the vacuum layer creates a surface, and the Si atoms on the surface will form unsaturated dangling bonds, which do not exist in reality, H atoms need to be added to the dangling bonds to ensure there are no empty dangling bonds.
[0096] Step 5: Perform first-principles relaxation calculations on the structural information of the Si supercell with the vacuum layer to obtain the structural information of the stable configuration of the Si supercell with the vacuum layer.
[0097] Specifically, the same cutoff energy as in step one is selected, XYZ is selected as the system periodic boundary condition, and the D3 system dispersion correction method is selected. First-principles structural relaxation calculations are performed on the structural information of the Si supercell with a vacuum layer to obtain the system energy corresponding to the Si supercell configuration with a vacuum layer. The system energy includes the structural information of the stable configuration of the Si supercell with a vacuum layer.
[0098] Step 6: Construct a Si supercell structure with gaps H and O based on the structural information of the stable configuration of the Si supercell with vacuum layer, and obtain the structural information of the Si supercell with gaps H and O.
[0099] The specific method is as follows:
[0100] The structural information of the stable Si supercell configuration with a vacuum layer is read, and a Si supercell structure with interstitial H and interstitial O atoms is constructed. Specifically, the structural information of the stable Si supercell configuration with a vacuum layer is read using Vesta software. Using the structure parameter option in the Edit Data directory, interstitial H and interstitial O atoms are added around the same Si atom to construct a Si supercell structure with interstitial H and interstitial O atoms, and the crystal structure file of the Si supercell structure with interstitial H and interstitial O atoms is obtained.
[0101] The structural information of the Si supercell with gaps H and O, which can be used in first-principles calculation software, is extracted from the crystal structure file of the Si supercell with gaps H and O. Specifically, the structural information of the Si supercell with gaps H and O is read from the crystal structure file of the Si supercell with gaps H and O using quantum chemical wavefunction analysis software and used as the input file for the first-principles calculation software (CP2K) to optimize the structure, thus obtaining the structural information of the Si supercell with gaps H and O that can be used in the first-principles calculation software.
[0102] Step 7: Perform first-principles relaxation calculations on the structural information of the Si supercell with gaps H and O to obtain the structural information of the stable configuration of the Si supercell with gaps H and O.
[0103] Specifically, the same cutoff energy as in step one is selected, XYZ is selected as the system periodic boundary condition, and the D3 system dispersion correction method is selected. First-principles relaxation calculations are performed on the structural information of the Si supercell with gaps H and O to obtain the system energy corresponding to the Si supercell with gaps H and O. The system energy includes the structural information of the stable configuration of the Si supercell with gaps H and O.
[0104] In this relaxation calculation step, the freezing keyword in CP2K is used to fix the bottom two layers of atoms on the Z-axis during the calculation to simulate the Si substrate.
[0105] Step 8: Set the bond length range of Si-O and Si-H bonds, and perform first-principles molecular dynamics calculations within the bond length range of Si-O and Si-H bonds based on the structural information of the stable configuration of the Si supercell with interstitial H and interstitial O. Statistically analyze the results and obtain the potential energy diagrams of interstitial H and interstitial O.
[0106] The bond lengths of the Si-O and Si-H bonds range from 0 to 0.3 nm. In the first-principles molecular dynamics calculations, the sampling energy change step size is 0.03 eV, the change frequency is 100, the total step size is 10,000 steps, and the duration of each step is 1 femtosecond. After the first-principles molecular dynamics calculations, the sampling results are analyzed using data analysis software. The bond length changes of the Si-O and Si-H bonds are statistically analyzed to obtain potential energy diagrams for interstitial H and interstitial O within a defined range.
[0107] The method disclosed in this embodiment, by combining various advanced software and tools and employing first-principles calculations, can accurately obtain the movement of interstitial H and interstitial O within the Si supercell as the system energy increases, and further infer the distribution of the potential energy surface. Because as the overall system energy increases, H and O gradually overcome the binding force of Si and move within a certain spatial range, statistical analysis of the movement positions of H and O within the supercell yields the potential energy surface near H and O. Based on the potential energy surface, the most likely migration routes of H and O within Si can be accurately predicted. Figure 2 As shown, the brightly colored areas are low-energy positions on the potential energy surface in space, indicating a higher probability of the presence of hydrogen or oxygen atoms. Therefore, we can more accurately predict the most likely migration routes of H and O in Si.
[0108] This method employs molecular dynamics calculations to obtain the potential energy surface around atoms, allowing for a more accurate prediction of the most likely migration routes of H and O in Si. Compared to relying on personal chemical intuition, this method provides more accurate atomic migration directions, offering strong theoretical support for subsequent computational simulations and thus more accurately predicting the suitable oxidation conditions for silicon oxide films. Furthermore, the method is clearly defined, easy to implement and operate, and can be readily applied to practical research and development.
[0109] Furthermore, by fixing the bottom two layers of atoms on the Z-axis and adding a vacuum layer, the surface conditions of silicon crystals can be simulated, more realistically reflecting the behavior of gaps H and O in silicon crystals.
[0110] Another embodiment of the present invention discloses a computational system for optimizing the oxidation conditions of silicon oxide thin films, such as... Figure 3 As shown, it includes:
[0111] The model building module is used to construct Si primitive cells, Si supercells, Si supercells with vacuum layers, and Si supercells with gaps H and O, and correspondingly generate Si primitive cell model information, Si supercell structural information, Si supercell structural information with vacuum layers, and Si supercell structural information with gaps H and O.
[0112] The first-principles relaxation calculation module, connected to the model building module, receives the output of the model building module and generates structural information of the Si primitive cell stable configuration, the Si supercell stable configuration, the Si supercell stable configuration with a vacuum layer, and the Si supercell stable configuration with gaps H and O. Simultaneously, it outputs the structural information of the Si primitive cell stable configuration, the Si supercell stable configuration, and the Si supercell stable configuration with a vacuum layer to the model building module.
[0113] The first-principles molecular dynamics calculation and statistics module, connected to the first-principles relaxation calculation module, is used to receive the structural information of the stable configuration of the Si supercell with gap H and gap O, and to perform first-principles molecular dynamics calculations within a preset range of Si-O and Si-H bond lengths based on the structural information of the stable configuration of the Si supercell with gap H and gap O, and to statistically analyze the results to obtain the potential energy diagrams of gap H and gap O.
[0114] Another embodiment of the present invention discloses a computer device, 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 optimizing the oxidation conditions of silicon oxide thin films as described in any of the above embodiments.
[0115] It should be noted that, unless otherwise defined, all technical and scientific terms used in this application's specification have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this application's specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used in this application's specification includes any and all combinations of one or more of the associated listed items.
[0116] The technical features of the above embodiments can be combined without changing the basic principles of this application. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0117] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the patent protection scope of this application should be determined by the appended claims.
Claims
1. A method for optimizing the oxidation conditions of silicon oxide thin films, characterized in that, include: Step 1: Obtain the Si unit cell model information and perform first-principles relaxation calculations to obtain the structural information of the stable configuration of the Si unit cell; Step 2: Expand the Si unit cell based on the structural information of the stable Si unit cell configuration to obtain the structural information of the Si supercell; Step 3: Perform first-principles relaxation calculations on the structural information of the Si supercell to obtain the structural information of the stable configuration of the Si supercell; Step 4: Based on the structural information of the stable configuration of the Si supercell, add a vacuum layer to the Si supercell and add H to the dangling bonds on the surface of Si atoms to obtain the structural information of the Si supercell with a vacuum layer. Step 5: Perform first-principles relaxation calculations on the structural information of the Si supercell with the vacuum layer to obtain the structural information of the stable configuration of the Si supercell with the vacuum layer; Step 6: Construct a Si supercell structure with gaps H and O based on the structural information of the stable configuration of the Si supercell with vacuum layer, and obtain the structural information of the Si supercell with gaps H and O; Step 7: Perform first-principles relaxation calculations on the Si supercell structure information with gaps H and O to obtain the structural information of the stable configuration of the Si supercell with gaps H and O; Step 8: Set the bond length range of Si-O and Si-H bonds, and perform first-principles molecular dynamics calculations within the bond length range of Si-O and Si-H bonds based on the structural information of the stable configuration of the Si supercell with interstitial H and interstitial O. Statistically analyze the results and obtain the potential energy diagrams of interstitial H and interstitial O.
2. The method according to claim 1, characterized in that, Step one includes: Obtain the crystal structure file of Si from an open-source materials database; Extract Si unit cell model information that can be used for first-principles calculation software from the crystal structure file of Si; The cutoff energy is set based on the maximum plane wave cutoff energy information of all elements in the pseudopotential file, and XYZ is selected as the system periodic boundary condition. The D3 system dispersion correction method is selected, and the first-principles structural relaxation calculation is performed on the Si unit cell model information to obtain the system energy corresponding to the Si unit cell configuration. The system energy includes the structural information of the stable configuration of the Si unit cell.
3. The method according to claim 2, characterized in that, Step two includes: The structural information of the stable configuration of the Si unit cell is read and the lattice vector of the Si crystal is transformed, changing the original 1×1×1 lattice vector to 2×2×1, to obtain the crystal structure file of the Si supercell. Structural information of the Si supercell that can be used for first-principles calculation software is extracted from the crystal structure file of the Si supercell.
4. The method according to claim 3, characterized in that, In step four, a 15 Å vacuum layer is added to the Si supercell.
5. The method according to claim 4, characterized in that, Step six includes: Read the structural information of the stable configuration of the Si supercell with vacuum layer, and construct the Si supercell structure with gaps H and O to obtain the crystal structure file of the Si supercell structure with gaps H and O; Structural information of the Si supercell with gaps H and O, which can be used in first-principles calculation software, is extracted from the crystal structure file of the Si supercell structure with gaps H and O.
6. The method according to claim 5, characterized in that, The first-principles relaxation calculation process in steps three, five, and seven includes: Select the same cutoff energy as in step one, select XYZ as the system periodic boundary condition, select the D3 system dispersion correction method, perform first-principles relaxation calculations on the target parameters, and obtain the structural information of the corresponding stable configuration.
7. The method according to claim 6, characterized in that, During the first-principles relaxation calculation of the structural information of the Si supercell with gaps H and O, the bottom two layers of atoms on the Z-axis are fixed to simulate the Si substrate.
8. The method according to claim 1, characterized in that, The bond lengths of the Si-O and Si-H bonds range from 0 to 0.3 nm.
9. A computational system for optimizing the oxidation conditions of silicon oxide thin films, characterized in that, include: The model building module is used to construct Si primitive cells, Si supercells, Si supercells with vacuum layers, and Si supercells with gaps H and O, and correspondingly generate Si primitive cell model information, Si supercell structural information, Si supercell structural information with vacuum layers, and Si supercell structural information with gaps H and O. The first-principles relaxation calculation module, connected to the model building module, receives the output of the model building module and generates structural information of the Si primitive cell stable configuration, the Si supercell stable configuration, the Si supercell stable configuration with a vacuum layer, and the Si supercell stable configuration with gaps H and O. Simultaneously, it outputs the structural information of the Si primitive cell stable configuration, the Si supercell stable configuration, and the Si supercell stable configuration with a vacuum layer to the model building module. The first-principles molecular dynamics calculation and statistics module, connected to the first-principles relaxation calculation module, is used to receive the structural information of the stable configuration of the Si supercell with gap H and gap O, and to perform first-principles molecular dynamics calculations within a preset range of Si-O and Si-H bond lengths based on the structural information of the stable configuration of the Si supercell with gap H and gap O, and to statistically analyze the results to obtain the potential energy diagrams of gap H and gap O.
10. A computer device, 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 optimizing the oxidation conditions of silicon oxide thin films according to any one of claims 1-8.