Conductivity regulation and control method for semiconductor heterojunctions with different crystal orientations

Abstract

The invention discloses a conductivity regulation and control method for semiconductor heterojunctions with different crystal orientations, and the method comprises the steps: obtaining the electrical energy band structures of two materials with different crystal orientations through employing a first principle calculation method, and calculating the effective mass of semiconductor materials with different crystal orientations; adopting a first principle calculation method to obtain conduction band orders of the two materials in different crystal orientations; solving the channel carrier concentration in the heterojunction composed of the two materials under different crystal orientations by combining a Schrodinger-Poisson equation; constructing a scattering mechanism of channel carriers in the heterojunction formed by the two materials under the different crystal orientations, and calculating the mobility of the channel carriers in the heterojunction formed by the two materials under the different crystal orientations; and according to the calculation model of the channel carrier concentration and mobility, obtaining the regulation and control method of the channel carrier conductance in the heterojunction composed of the two materials under different crystal orientations. According to the method, the relation between the physical parameters and the crystal orientation of the semiconductor heterojunction is extracted, efficient regulation and control of multi-system heterojunction conductivity are achieved, the model calculation amount is small, and universality is high.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor control method technology, specifically relating to a method for controlling the conductivity of semiconductor heterojunctions with different crystal orientations. Background Technology

[0002] With the rapid iteration of semiconductor devices towards higher frequencies, higher power, and lower power consumption, heterojunctions, with their unique bandgap engineering advantages, have become a key structure in core fields such as radio frequency devices and power electronic devices. However, the conductivity characteristics of heterojunctions directly determine core performance aspects such as device switching speed and conduction loss, and their control precision and stability have become a core bottleneck restricting breakthroughs in device performance. Existing heterojunction conductivity control methods mostly focus on optimizing structural parameters such as doping concentration and barrier layer thickness, neglecting the significant impact of the anisotropy of semiconductor material crystal orientation on carrier transport characteristics and bandgap structure relationships. Different crystal orientations directly alter carrier scattering mechanisms, interface charge transfer efficiency, and bandgap shifts, leading to significant differences in heterojunction conductivity performance. Therefore, it is urgent to establish a semiconductor heterojunction conductivity control system based on different crystal orientations to provide key technical support for the design and optimization of high-performance semiconductor devices. Summary of the Invention

[0003] The purpose of this invention is to provide a method for controlling the conductivity of semiconductor heterojunctions with different crystal orientations, which has the characteristics of precise and stable control of conductivity.

[0004] The technical solution adopted in this invention is a method for controlling the conductivity of semiconductor heterojunctions with different crystal orientations, and the steps are as follows: Step 1: Use first-principles calculations to obtain the electrical band structures of two different semiconductor materials with different crystal orientations, and calculate the effective mass of the two semiconductor materials with different crystal orientations. Step 2: Use first-principles calculations to obtain the conduction band order of two different semiconductor materials with different crystal orientations; Step 3: Solve the Schrödinger-Poisson equations simultaneously to determine the channel carrier concentration in heterojunctions composed of two semiconductor materials with different crystal orientations; Step 4: Construct the scattering mechanism of channel carriers in a heterojunction composed of two semiconductor materials with different crystal orientations, and calculate the mobility of channel carriers in a heterojunction composed of two semiconductor materials with different crystal orientations. Step 5: Based on the calculation model of channel carrier concentration and mobility, obtain the method for controlling the channel carrier conductance in heterojunctions composed of two semiconductor materials with different crystal orientations.

[0005] The invention is further characterized in that, Furthermore, the two semiconductor materials are respectively selected from gallium nitride, aluminum nitride, boron nitride, aluminum gallium nitride, aluminum indium nitride, aluminum indium gallium nitride, boron gallium nitride, boron aluminum nitride, boron aluminum gallium nitride, gallium oxide, diamond, and silicon, and the two are heterogeneous.

[0006] Furthermore, the expression for calculating the effective mass of the material based on the electrical band structure in step 1 is as follows:

[0007] in, E It is energy. k It's a wave arrow. m * It is the effective mass of charge carriers, and the unit is the static mass of electrons. m 0, It is the reduced Planck constant.

[0008] Furthermore, crystal orientation includes , and .

[0009] Furthermore, the first-principles calculations were performed using one of the following software: ABACUS, VASP, CASTEP, ABINIT, QuantumEspresso, Materials Studio, Gassian, and WIEN2K.

[0010] Furthermore, the specific expression for the Schrödinger-Poisson equation in step 3 is as follows:

[0011] in V ( z ) is the electron potential energy. E and It consists of electron energy and wave function; Potential energy V ( z ) and electrostatic potential satisfy ; in It is a step function, Δ E C It is a heterojunction conduction band order; electrostatic potential It can be calculated using the Poisson equation:

[0012] in n e , These represent the electron concentration and the charge concentration at the heterojunction interface, where i represents the i-th interface. Next, calculate the channel carrier concentration for heterojunctions with different crystal orientations. .

[0013] Furthermore, in step 4, the scattering mechanisms of channel carriers in heterojunctions composed of two semiconductor materials with different crystal orientations include acoustic phonon-related scattering, optical phonon-related scattering, interface roughness scattering, modulation doping scattering, long-range surface roughness scattering, alloy disorder scattering, alloy composition fluctuation scattering, and dislocation scattering.

[0014] Furthermore, in step 4, the relationship between the channel carrier mobility and different scattering mechanisms in the heterojunction composed of two semiconductor materials with different crystal orientations is as follows: .in Indicates the total mobility. m i For each scattering mechanism, the mobility is... ,in q For electron charge, t i For the relaxation time of a single scattering mechanism.

[0015] Furthermore, in step 5, the correlation function between the channel carrier concentration n and the heterojunction structural and physical parameters is established and solved. n =F1(P struct P phys ), mobility Correlation function between heterojunction structural parameters and physical parameters =F2(P struct P phys ), P struct P is the set of structural parameters. phys It is a set of physical parameters; then, according to the conductivity formula... , q For electron charge, n For carrier concentration, m The total mobility is quantified by adjusting parameters to control conductivity.

[0016] Furthermore, the structural parameters include the barrier layer alloy composition, barrier layer thickness, barrier layer modulation doping thickness, and barrier layer modulation doping concentration; the physical parameters include the Schottky barrier height, heterointerface root mean square roughness, heterointerface correlation length, barrier layer surface root mean square roughness, barrier layer surface correlation length, and dislocation concentration.

[0017] Compared with existing methods that only optimize structural parameters, the conductivity control method of semiconductor heterojunctions with different crystal orientations in this invention has the following advantages: By incorporating the coupling relationship between crystal anisotropy and structural / physical parameters, and through first-principles calculations and explicit quantitative models, precise and stable control of heterojunction conductivity is achieved, overcoming the bottlenecks of low control precision and poor stability in traditional methods. It has strong versatility, is compatible with a variety of binary heterojunction systems and typical crystal orientations, has a standardized and efficient calculation process, and can provide direct guidance for device process optimization. It is easy to apply in engineering and fills the research gap on the influence of crystal orientation on the conductance control of heterojunctions, providing key technical support for the design of high-performance semiconductor devices. Attached Figure Description

[0018] Figure 1 This is a flowchart of the conductivity control method for semiconductor heterojunctions with different crystal orientations according to the present invention. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0020] Example 1 The conductivity modulation method for semiconductor heterojunctions with different crystal orientations of the present invention is as follows: Figure 1 As shown, it includes the following steps: Step 1: Use first-principles calculations to obtain the electrical band structures of semiconductor material 1 and semiconductor material 2 with different crystal orientations, and then calculate the effective mass of semiconductor materials 1 and 2 with different crystal orientations.

[0021] Semiconductor material 1 and material 2 are respectively selected from gallium nitride, aluminum nitride, boron nitride, aluminum gallium nitride, aluminum indium nitride, aluminum indium gallium nitride, boron gallium nitride, boron aluminum nitride, boron aluminum gallium nitride, gallium oxide, diamond, and silicon, and the two are heterogeneous.

[0022] Crystal orientation includes , , .

[0023] Step 2: Use first-principles calculations to obtain the conduction band order of semiconductor materials 1 and 2 in different crystal orientations; Step 2.1: Use first-principles calculation software to obtain the complete electrical band structures of materials 1 and 2 with different crystal orientations; Step 2.2: Using the Fermi level as a reference, locate the energy corresponding to the lowest point of the conduction band in the heterojunction band structure of each crystal orientation through the band analysis module of the first-principles calculation software, and extract the energy values ​​of the conduction band bottom of material 1 and material 2. Step 2.3: Calculate the difference in conduction band bottom energy between material 1 and material 2 in the same crystal direction to obtain the conduction band order of the heterojunction corresponding to different crystal orientations; Step 3: Solve the Schrödinger-Poisson equations simultaneously to determine the channel carrier concentration in the heterojunction composed of material 1 and material 2 with different crystal orientations; Step 4: Construct the scattering mechanism of channel carriers in heterojunctions composed of different crystal-down materials 1 and 2, and calculate the mobility of channel carriers in heterojunctions composed of different crystal-down materials 1 and 2.

[0024] Step 5: Based on the calculation model of channel carrier concentration and mobility, obtain the method for controlling the channel carrier conductance in heterojunctions composed of different crystal orientation materials 1 and 2.

[0025] Example 2 Based on Example 1, step 1 specifically involves: inputting the crystal structure parameters of semiconductor materials 1 and 2, and for different crystal orientations, using a first-principles calculation method based on density functional theory (DFT) to solve the Kohn-Sham equation: ), In the formula, For electron kinetic energy operator, For external force field, For Hartley's advantage, In order to exchange the correlation potential, Let i be the wavefunction of the i-th single electron. For the i-th single-electron energy level, obtain the electrical band structure of each crystal orientation, and then apply the formula... ,in E For energy, k For wave vector, The effective mass of the charge carriers, To reduce Planck's constant, the effective carrier mass for the two materials with different crystal orientations was calculated.

[0026] First-principles calculations were performed using one of the following software: ABACUS, VASP, CASTEP, ABINIT, Quantum Espresso, Materials Studio, Gassian, and WIEN2K.

[0027] Example 3 Based on Example 2, Step 3 specifically involves: based on the effective mass of charge carriers, the conduction band order, the surface charge concentration, and the Schrödinger-Poisson equation expression, by assuming an initial electrostatic potential, solving the equation to obtain the electron concentration and updating the electrostatic potential in an iterative process. The specific expression of the Schrödinger-Poisson equation is:

[0028] in V ( z) is the electron potential energy. E and It consists of electron energy and wave function; Potential energy V ( z ) and electrostatic potential satisfy ,in It is a step function, Δ E C It is a heterojunction conduction band order; electrostatic potential Calculated using the Poisson equation:

[0029] in n e , These represent the electron concentration and the charge concentration at the heterojunction interface, where i represents the i-th interface. Finally by , ( n e ( (This refers to the electron concentration) Solving for the channel carrier concentration in heterojunctions with different crystal orientations. n .

[0030] Example 4 Based on Example 3, in step 4, the scattering mechanism of channel carriers in heterojunctions composed of materials 1 and 2 with different crystal orientations includes acoustic phonon-related scattering, optical phonon-related scattering, interface roughness scattering, modulation doping scattering, long-range surface roughness scattering, alloy disorder scattering, alloy composition fluctuation scattering, and dislocation scattering.

[0031] Specifically, relaxation time models for specific scattering mechanisms are constructed for different crystal orientations, taking into account the effective mass of charge carriers. ,in q For electron charge, t i Calculate the mobility corresponding to each scattering mechanism for the relaxation time of a single scattering mechanism, and then based on... The superposition relationship was used to obtain the total mobility of charge carriers in the heterojunction channel under different crystal orientations. .

[0032] In step 5, the channel carrier concentration is established and solved. n Correlation function between heterojunction structural parameters and physical parameters n =F1(P struct P phys ), mobility Correlation function between heterojunction structural parameters and physical parameters =F2(P structP phys ), P struct P is the set of structural parameters. phys A set of physical parameters; Then, through the conductivity formula In the formula, For heterojunction channel conductivity, n The channel carrier concentration, q The amount of electron charge. m To calculate the total mobility, conductance in different crystal orientations is calculated. Combining the structural and physical parameters of the heterojunction, a precise method for controlling the channel carrier conductance is derived.

[0033] Structural parameters include the alloy composition of the barrier layer, the thickness of the barrier layer, the modulation doping thickness of the barrier layer, and the modulation doping concentration of the barrier layer. The physical parameters include Schottky barrier height, root mean square roughness of the heterostructure, heterostructure correlation length, root mean square roughness of the barrier layer surface, correlation length of the barrier layer surface, and dislocation concentration.

[0034] Through the above methods, the conductivity control method of semiconductor heterojunctions with different crystal orientations of the present invention takes into account the coupling relationship between crystal orientation characteristics and structural / physical parameters, and extracts accurate values ​​of carrier concentration and mobility for different crystal orientations. This allows for precise control of heterojunction conductivity, overcoming the bottlenecks of low control accuracy and poor stability of traditional methods. The method is highly universal, adaptable to various binary heterojunction systems and typical crystal orientations, with standardized and efficient calculation processes. It can also provide direct guidance for device process optimization and is easy to apply in engineering. Furthermore, it fills the research gap on the influence of crystal orientation on heterojunction conductivity control, providing key technical support for the design of high-performance semiconductor devices.

[0035] It is also highly efficient in computation and easy to apply in engineering.

[0036] Example 5 The present invention discloses a method for controlling the conductivity of semiconductor heterojunctions with different crystal orientations, using AlGaN / GaN semiconductor materials, and the steps are as follows: Step 1: Using Materials Studio software, input the crystal structure parameters of AlGaN and Gallium Nitride (GaN) for... , , Three crystal orientations were analyzed using first-principles calculations to obtain the band structure for each orientation. This was based on the effective mass formula. Numerical fitting was performed near the conduction band bottom to calculate the effective electron mass. .

[0037] Step 2: Obtain AlGaN and GaN bulk materials in , , The energy band structure is determined by crystal orientation. The conduction band bottom energy values ​​for each crystal orientation are precisely extracted and aligned with a unified reference energy level. The energy difference between the two materials at the same crystal orientation's conduction band bottom is calculated, thus obtaining the conduction band order Δ for that crystal orientation. E c .

[0038] Step 3: Construct a one-dimensional AlGaN / GaN heterojunction model and determine the effective mass of each crystal orientation. and conduction band Δ E c As a key parameter, the Schrödinger-Poisson equations are substituted into the equations, and the influence of surface charge concentration and interface state is considered. The carrier concentration of each crystal channel is obtained through iterative solution.

[0039] Step 4: Construct a scattering mechanism model, including acoustic phonon deformation potential scattering, optical phonon scattering, interface roughness scattering, modulation doping scattering, alloy disorder scattering, long-range surface roughness scattering, alloy disorder scattering, alloy composition fluctuation scattering, and dislocation scattering, combined with each crystal orientation. Based on preset physical parameters, establish relaxation time models for each mechanism. .pass Calculate the mobility of the single scattering mechanism, and then based on The total mobility is obtained by superimposing the results.

[0040] Step 5: Based on the optimal crystal orientation, and using structural parameters including the barrier layer alloy composition, barrier layer thickness, barrier layer modulation doping thickness, and barrier layer modulation doping concentration, as well as physical parameters including Schottky barrier height, heterointerface root-mean-square roughness, heterointerface correlation length, barrier layer surface root-mean-square roughness, barrier layer surface correlation length, dislocation concentration, and a correlation model with carrier concentration and mobility, the channel carrier concentration and total mobility are integrated using the conductivity formula. ,in q For electron charge, n For carrier concentration, m For the total migration rate, establish , , A method for controlling the conductivity of heterojunctions with different crystal orientations, achieving precise control of conductivity.

[0041] Example 6 The present invention relates to a method for controlling the conductivity of semiconductor heterojunctions with different crystal orientations, wherein the semiconductor material is a c-BN / diamond heterojunction. Step 1: Using VASP software, input the crystal structure parameters of cubic c-BN (cubic boron nitride) and diamond, targeting... , , First-principles calculations were performed in three crystal orientations to obtain the band structure for each orientation. This was based on the effective mass formula. Numerical fitting was performed near the bottom of the conduction band to calculate the effective electron mass of different crystals.

[0042] Step 2: Obtaining c-BN and diamond materials in , , The energy band structure is oriented downwards. The conduction band bottom energy values ​​for each crystal orientation are precisely extracted and aligned with a unified reference energy level. The energy difference between the conduction band bottoms of the two materials in the same crystal orientation is calculated, thus obtaining the conduction band order Δ for that crystal orientation. E c .

[0043] Step 3: Construct one-dimensional c-BN and diamond heterostructure models, and determine the effective mass of each crystal orientation. m * and conduction band Δ E c As a key parameter, the Schrödinger-Poisson equations are substituted into the equations, and the influence of surface charge concentration and interface state is considered. The carrier concentration of each crystal channel is obtained through iterative solution.

[0044] Step 4: Construct a scattering mechanism model, including acoustic phonon deformation potential scattering, optical phonon scattering, interface roughness scattering, alloy disorder scattering, long-range surface roughness scattering, and modulation doping scattering, combined with various crystal orientations. m * Based on preset physical parameters, establish relaxation time models for each mechanism. t i .pass Calculate the mobility of the single scattering mechanism, and then based on The total mobility is obtained by superimposing the results.

[0045] Step 5: Based on the optimal crystal orientation and structural parameters (including barrier layer thickness, barrier layer modulation doping thickness, and barrier layer modulation doping concentration), and physical parameters (including Schottky barrier height, heterointerface root-mean-square roughness, heterointerface correlation length, barrier layer surface root-mean-square roughness, and barrier layer surface correlation length), a correlation model is established with carrier concentration and mobility. This model integrates channel carrier concentration and total mobility, and is then applied using the conductivity formula. ,in q For electron charge, n For carrier concentration, m For the total migration rate, establish , , A method for controlling the conductivity of heterojunctions with different crystal orientations, achieving precise control of conductivity.

[0046] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for controlling the conductivity of semiconductor heterojunctions with different crystal orientations, characterized in that, The specific steps are as follows: Step 1: Use first-principles calculations to obtain the electrical band structures of two different semiconductor materials with different crystal orientations, and calculate the effective mass of the two semiconductor materials with different crystal orientations. Step 2: Use first-principles calculations to obtain the conduction band order of two different semiconductor materials with different crystal orientations; Step 3: Solve the Schrödinger-Poisson equations simultaneously to determine the channel carrier concentration in heterojunctions composed of two semiconductor materials with different crystal orientations; Step 4: Construct the scattering mechanism of channel carriers in a heterojunction composed of two semiconductor materials with different crystal orientations, and calculate the mobility of channel carriers in a heterojunction composed of two semiconductor materials with different crystal orientations. Step 5: Based on the calculation model of channel carrier concentration and mobility, obtain the method for controlling the channel carrier conductance in heterojunctions composed of two semiconductor materials with different crystal orientations.

2. The method for controlling the conductivity of semiconductor heterojunctions with different crystal orientations according to claim 1, characterized in that, The two semiconductor materials are respectively selected from gallium nitride, aluminum nitride, boron nitride, aluminum gallium nitride, aluminum indium nitride, aluminum indium gallium nitride, boron gallium nitride, boron aluminum nitride, boron aluminum gallium nitride, gallium oxide, diamond, and silicon, and the two are heterogeneous.

3. The method for controlling the conductivity of semiconductor heterojunctions with different crystal orientations according to claim 1, characterized in that, The expression for calculating the effective mass of the material based on the electrical band structure in step 1 is as follows: in, E It is energy. k It's a wave arrow. It is the effective mass of charge carriers, and the unit is the electron static mass m0. It is the reduced Planck constant.

4. The method for controlling the conductivity of semiconductor heterojunctions with different crystal orientations according to claim 1, characterized in that, The crystal orientation includes , , .

5. The method for controlling the conductivity of semiconductor heterojunctions with different crystal orientations according to claim 1, characterized in that, The first principle calculations were performed using one of the following software: ABACUS, VASP, CASTEP, ABINIT, Quantum Espresso, Materials Studio, Gassian, and WIEN2K.

6. The method for controlling the conductivity of semiconductor heterojunctions with different crystal orientations according to claim 1, characterized in that, In step 3, the specific expression of the Schrödinger-Poisson equation is as follows: in V ( z ) is the electron potential energy. E and It consists of electron energy and wave function; Potential energy V ( z ) and electrostatic potential satisfy ,in It is a step function, Δ E C It is a heterojunction conduction band order; electrostatic potential Calculated using the Poisson equation: in n e , These represent the electron concentration and the charge concentration at the heterojunction interface, where i represents the i-th interface. Next, calculate the channel carrier concentration for heterojunctions with different crystal orientations. .

7. The method for controlling the conductivity of semiconductor heterojunctions with different crystal orientations according to claim 1, characterized in that, In step 4, the scattering mechanism of channel carriers in the heterojunction composed of two semiconductor materials with different crystal orientations includes acoustic phonon-related scattering, optical phonon-related scattering, interface roughness scattering, modulation doping scattering, long-range surface roughness scattering, alloy disorder scattering, alloy composition fluctuation scattering, and dislocation scattering.

8. The method for controlling the conductivity of semiconductor heterojunctions with different crystal orientations according to claim 1, characterized in that, In step 4, the relationship between the channel carrier mobility and different scattering mechanisms in the heterojunction composed of two semiconductor materials with different crystal orientations is as follows: in Indicates the total mobility. μ i For each scattering mechanism, the mobility is... ,in q For electron charge, τ i For the relaxation time of a single scattering mechanism.

9. The method for controlling the conductivity of semiconductor heterojunctions with different crystal orientations according to claim 1, characterized in that, In step 5, the channel carrier concentration is established and solved. n Correlation function between heterojunction structural parameters and physical parameters n =F1(P struct P phys ), mobility Correlation function between heterojunction structural parameters and physical parameters =F2(P struct P phys ), P struct P is the set of structural parameters. phys It is a set of physical parameters; then, according to the conductivity formula... , q For electron charge, n For carrier concentration, μ The total mobility is quantified by adjusting parameters to control conductivity.

10. The method for controlling the conductivity of semiconductor heterojunctions with different crystal orientations according to claim 9, characterized in that, The structural parameters include the barrier layer alloy composition, barrier layer thickness, barrier layer modulation doping thickness, and barrier layer modulation doping concentration. The physical parameters include Schottky barrier height, root mean square roughness of the heterostructure, heterostructure correlation length, root mean square roughness of the barrier layer surface, correlation length of the barrier layer surface, and dislocation concentration.

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