CN114062371A - Method and system for generating life image of silicon carbide wafer body and storage medium - Google Patents
Method and system for generating life image of silicon carbide wafer body and storage medium Download PDFInfo
- Publication number
- CN114062371A CN114062371A CN202111347397.8A CN202111347397A CN114062371A CN 114062371 A CN114062371 A CN 114062371A CN 202111347397 A CN202111347397 A CN 202111347397A CN 114062371 A CN114062371 A CN 114062371A
- Authority
- CN
- China
- Prior art keywords
- silicon carbide
- image
- carbide wafer
- equation
- wafer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 title claims abstract description 179
- 229910010271 silicon carbide Inorganic materials 0.000 title claims abstract description 179
- 238000000034 method Methods 0.000 title claims abstract description 29
- 238000003860 storage Methods 0.000 title claims abstract description 7
- 238000003384 imaging method Methods 0.000 claims abstract description 27
- 238000005424 photoluminescence Methods 0.000 claims abstract description 14
- 239000011159 matrix material Substances 0.000 claims description 79
- 230000006798 recombination Effects 0.000 claims description 54
- 238000005215 recombination Methods 0.000 claims description 54
- 239000000969 carrier Substances 0.000 claims description 9
- 238000004364 calculation method Methods 0.000 claims description 8
- 238000009792 diffusion process Methods 0.000 claims description 7
- 238000010521 absorption reaction Methods 0.000 claims description 6
- 238000006243 chemical reaction Methods 0.000 claims description 3
- 238000004590 computer program Methods 0.000 claims description 3
- 230000031700 light absorption Effects 0.000 claims description 2
- 235000012431 wafers Nutrition 0.000 description 146
- 230000006870 function Effects 0.000 description 9
- 238000010586 diagram Methods 0.000 description 4
- 230000005284 excitation Effects 0.000 description 4
- 230000007547 defect Effects 0.000 description 3
- 238000009826 distribution Methods 0.000 description 3
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 description 2
- 238000000295 emission spectrum Methods 0.000 description 2
- 230000001678 irradiating effect Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000001066 destructive effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000000695 excitation spectrum Methods 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/8851—Scan or image signal processing specially adapted therefor, e.g. for scan signal adjustment, for detecting different kinds of defects, for compensating for structures, markings, edges
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F17/00—Digital computing or data processing equipment or methods, specially adapted for specific functions
- G06F17/10—Complex mathematical operations
- G06F17/11—Complex mathematical operations for solving equations, e.g. nonlinear equations, general mathematical optimization problems
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F17/00—Digital computing or data processing equipment or methods, specially adapted for specific functions
- G06F17/10—Complex mathematical operations
- G06F17/16—Matrix or vector computation, e.g. matrix-matrix or matrix-vector multiplication, matrix factorization
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T11/00—2D [Two Dimensional] image generation
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/8851—Scan or image signal processing specially adapted therefor, e.g. for scan signal adjustment, for detecting different kinds of defects, for compensating for structures, markings, edges
- G01N2021/8887—Scan or image signal processing specially adapted therefor, e.g. for scan signal adjustment, for detecting different kinds of defects, for compensating for structures, markings, edges based on image processing techniques
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Mathematical Physics (AREA)
- Theoretical Computer Science (AREA)
- Data Mining & Analysis (AREA)
- Computational Mathematics (AREA)
- Mathematical Analysis (AREA)
- Mathematical Optimization (AREA)
- Pure & Applied Mathematics (AREA)
- Biochemistry (AREA)
- Immunology (AREA)
- Software Systems (AREA)
- General Engineering & Computer Science (AREA)
- Algebra (AREA)
- Pathology (AREA)
- Databases & Information Systems (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- General Health & Medical Sciences (AREA)
- Operations Research (AREA)
- Signal Processing (AREA)
- Computer Vision & Pattern Recognition (AREA)
- Computing Systems (AREA)
- Testing Or Measuring Of Semiconductors Or The Like (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
Abstract
The invention provides a method, a system and a storage medium for generating the service life of a silicon carbide wafer body, and relates to the technical field of silicon carbide. Compared with a microwave imaging method, the method has the advantages that the photoluminescence imaging instrument has higher speed, and meanwhile, the volume service life image of the silicon carbide wafer can be directly obtained instead of the equivalent minority carrier service life image, so that the representation result is more accurate.
Description
Technical Field
The invention relates to the technical field of silicon carbide, in particular to a method and a system for generating life images of a silicon carbide wafer surface body and a storage medium.
Background
The minority carrier lifetime of a silicon carbide wafer is an important parameter in determining the quality of a silicon carbide wafer, and can be measured in a non-destructive, non-contact manner, typically by microwave techniques.
Recent technological developments have made it possible to obtain equivalent minority carrier lifetime images of silicon carbide wafers using microwave imaging techniques, but this technique still has some disadvantages. First, the minority carrier lifetime of a silicon carbide wafer consists of two components, namely the surface recombination rate of the silicon carbide wafer and the minority carrier lifetime within the silicon carbide wafer. However, the existing microwave imaging technology can only obtain an equivalent minority carrier lifetime image by measuring the photoconductive change value of the whole silicon carbide wafer, and the equivalent minority carrier lifetime has the following relationship with the bulk lifetime and the surface recombination rate:
wherein tau iseffIs the equivalent carrier lifetime, τbIt is the bulk lifetime, S is the surface recombination rate, so knowing the equivalent minority carrier lifetime image alone is not able to distinguish between the surface recombination rate of silicon carbide and the bulk minority carrier lifetime of silicon carbide.
Disclosure of Invention
The present invention is directed to solving the above-mentioned problems of the background art and to providing a method, a system and a storage medium for generating lifetime images of silicon carbide wafer bodies.
In order to achieve the above object, the present invention firstly proposes a method for generating lifetime images of silicon carbide wafer bodies, comprising the steps of:
obtaining a PL image of the silicon carbide wafer;
establishing a PL signal intensity equation PL count ═ B Δ n Δ p, wherein PL count represents PL signal intensity, B represents light absorption reflection coefficient, Δ n represents minority carrier concentration, and Δ p represents majority carrier concentration;
establishing a carrier continuity equation
Where z represents the wafer depth coordinate, t represents time, Δ n represents the minority carrier concentration, Dn represents the minority carrier diffusion coefficient, τbRepresenting the lifetime of the silicon carbide wafer body, and G (z, t) representing the generation rate of minority carriers;
establishing a silicon carbide wafer front surface recombination velocity equation
Equation of recombination velocity of rear surface of silicon carbide wafer
Wherein z-0 represents the front surface of the SiC wafer, z-W represents the back surface of the SiC wafer, W is the SiC wafer depth, S0Representing the front surface recombination rate of the silicon carbide wafer, and Sw representing the back surface recombination rate of the silicon carbide wafer;
combining the PL signal intensity equation, the carrier continuity equation, the SiC wafer front surface recombination rate equation and the SiC wafer rear surface recombination rate equation, and calculating to obtain a functional relation between the service life of the SiC wafer body and the PL signal intensity;
and generating a service life image of the silicon carbide wafer body according to the PL image and the functional relation.
Optionally, the generating the lifetime image of the silicon carbide wafer body according to the PL image and the functional relationship comprises the following steps:
acquiring a first numerical matrix, wherein the first numerical matrix is a numerical matrix of a PL image;
converting the first numerical matrix into a second numerical matrix according to the functional relation, wherein the second numerical matrix is a numerical matrix of the body life image;
and obtaining a volume life image of the silicon carbide wafer according to the second numerical matrix.
Optionally, the obtaining the first numerical matrix further includes the following steps: obtaining the imaging size of the silicon carbide wafer; the PL image is converted to a first matrix of values based on the imaged dimensions.
Alternatively, PL images of silicon carbide wafers are obtained by a photoluminescence imaging instrument.
The embodiment of the invention also provides a system for generating the service life image of the silicon carbide wafer body, which comprises:
an image acquisition module configured to acquire a PL image of a silicon carbide wafer;
a first equation module configured to establish a PL signal intensity equation PL count ═ B Δ n Δ p, where PL count represents PL signal intensity, B represents light reflection absorption coefficient, Δ n represents minority carrier concentration, Δ p represents majority carrier concentration;
a second equation module configured to establish a carrier continuity equation
Where z represents the wafer depth coordinate, t represents time, Δ n represents the minority carrier concentration, Dn represents the minority carrier diffusion coefficient, τbRepresenting the lifetime of the silicon carbide wafer body, and G (z, t) representing the generation rate of minority carriers;
a third equation module configured to establish a SiC wafer front surface recombination velocity equation
Equation of recombination velocity of rear surface of silicon carbide wafer
Wherein S0Representing the front surface recombination rate of the silicon carbide wafer, and Sw representing the back surface recombination rate of the silicon carbide wafer;
the first calculation module is configured to simultaneously establish the PL signal intensity equation, the carrier continuity equation, the SiC wafer front surface recombination rate equation and the SiC wafer rear surface recombination rate equation, and calculate a functional relation between the service life of the SiC wafer body and the PL signal intensity;
and the second calculation module is configured to generate a silicon carbide wafer life image according to the PL image and the functional relation.
Optionally, the second computing module further includes:
a matrix acquisition module configured to acquire a first numerical matrix, the first numerical matrix being a numerical matrix of a PL image;
a matrix conversion module configured to convert the first numerical matrix into a second numerical matrix according to the functional relationship, the second numerical matrix being a numerical matrix of a body life image;
an image generation module configured to obtain a volume lifetime image of the silicon carbide wafer from the second numerical matrix.
Optionally, the matrix obtaining module further includes: obtaining the imaging size of the silicon carbide wafer; the PL image is converted to a first matrix of values based on the imaged dimensions.
The invention has the beneficial effects that:
the invention provides a method for generating a service life image of a silicon carbide wafer body, which comprises the steps of obtaining a PL image of a silicon carbide wafer by using a photoluminescence imaging instrument, obtaining a function relation between the service life of the silicon carbide wafer body and the PL signal intensity by using a minority carrier continuity equation, a silicon carbide wafer front surface recombination rate equation, a silicon carbide wafer rear surface recombination rate equation and a PL signal intensity equation through computer numerical calculation and solving a partial differential equation, and obtaining the service life image of the silicon carbide wafer body according to the function relation and the PL image. Compared with a microwave imaging method, the photoluminescence imaging instrument has higher speed, and meanwhile, a life image of a silicon carbide wafer can be directly obtained instead of an equivalent minority carrier life image, so that the representation result is more accurate.
The features and advantages of the present invention will be described in detail by embodiments in conjunction with the accompanying drawings.
Drawings
FIG. 1 is a block diagram of a method for generating lifetime images of silicon carbide wafers according to an embodiment of the present invention;
FIG. 2 is a second flowchart of a method for generating lifetime images of SiC wafer according to an embodiment of the present invention;
fig. 3 is a third flowchart of a method for generating a lifetime image of a silicon carbide wafer according to an embodiment of the present invention;
FIG. 4 is a system block diagram of a system for generating lifetime images of silicon carbide wafers according to an embodiment of the present invention;
FIG. 5 is a second system block diagram of a system for generating lifetime images of SiC wafer according to an embodiment of the present invention;
fig. 6 is a third system block diagram of a system for generating a lifetime image of a silicon carbide wafer according to an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail below with reference to specific examples in order to facilitate understanding by those skilled in the art.
Referring to fig. 1, an embodiment of the present invention provides a method for generating a lifetime image of a silicon carbide wafer, including the following steps:
step S10, acquiring a PL image of the silicon carbide wafer;
step S20, establishing a PL signal intensity equation PL count ═ B Δ n Δ p, where PL count represents PL signal intensity, B represents light reflection absorption coefficient, Δ n represents minority carrier concentration, and Δ p represents non-equilibrium state hole concentration;
step S30, establishing a carrier continuity equation
Where z represents the wafer depth coordinate, t represents time, Δ n represents the minority carrier concentration, Dn represents the minority carrier diffusion coefficient, τbRepresenting the lifetime of the silicon carbide wafer body, and G (z, t) representing the generation rate of minority carriers;
step S40, establishing a silicon carbide wafer front surface recombination velocity equation
Equation of recombination velocity of rear surface of silicon carbide wafer
Wherein S0Representing the front surface recombination rate of the silicon carbide wafer, and Sw representing the back surface recombination rate of the silicon carbide wafer;
step S50, the functional relation between the service life of the silicon carbide wafer and the PL signal intensity is calculated by combining the PL signal intensity equation, the carrier continuity equation, the silicon carbide wafer front surface recombination rate equation and the silicon carbide wafer rear surface recombination rate equation;
in step S60, a bulk lifetime image of the sic wafer is generated from the functional relationship between the bulk lifetime of the sic wafer and the PL signal intensity.
The invention provides a method for generating a service life image of a silicon carbide wafer body, which comprises the steps of obtaining a PL image of a silicon carbide wafer by using a photoluminescence imaging instrument, obtaining a function relation between the service life of the silicon carbide wafer body and the PL signal intensity by using a minority carrier continuity equation, a silicon carbide wafer front surface recombination rate equation, a silicon carbide wafer rear surface recombination rate equation and a PL signal intensity equation through computer numerical calculation and solving a partial differential equation, and obtaining the service life image of the silicon carbide wafer body according to the function relation and the PL image. Compared with a microwave imaging method, the method has the advantage that the speed is higher through the photoluminescence imaging instrument, and the photoluminescence imaging instrument can basically finish the microwave imaging within a few seconds. Meanwhile, the life image of the silicon carbide wafer can be directly obtained, the life image of the equivalent minority carrier is not obtained, and the representation result is more accurate.
Furthermore, the method for generating the service life image of the silicon carbide wafer body utilizes the PL signal to measure and obtain the PL excitation spectrum of the surface defect of the silicon carbide wafer, thereby being capable of continuously and deeply analyzing the electrical performance parameters of the surface defect of the silicon carbide wafer and having important scientific value.
The steps of a lifetime image forming method for a silicon carbide wafer according to an embodiment of the present invention will be described in more detail with reference to the drawings and examples.
In step S10, a PL image of the silicon carbide wafer is acquired.
Photoluminescence imaging equipment is used for the silicon carbide wafer to generate a photoluminescence image of the silicon carbide wafer, also called a PL image, and the PL image can be regarded as a numerical matrix representing PL signal intensity.
In this example, the PL excitation light exposure time was set to 1 second, the PL excitation light intensity was set to the intensity of 1 sun illumination, and then the silicon carbide wafer was irradiated with the PL excitation light, causing the silicon carbide wafer to produce a PL emission spectrum, and finally an image of the PL emission spectrum intensity was obtained with a photodetector.
In other embodiments, the PL image of the sic wafer may be obtained after the steps of establishing the PL signal intensity equation, establishing the carrier continuity equation, and the like are performed, and the technical effect to be achieved by the present invention may be achieved as long as the step of obtaining the PL image of the sic wafer is performed before the step of generating the bulk lifetime image of the sic wafer according to the functional relationship between the bulk lifetime of the sic wafer and the PL signal intensity.
In step S20, a PL signal intensity equation PL count ═ B Δ n Δ p is established, where PL count represents PL signal intensity, B represents light reflection absorption coefficient, Δ n represents minority carrier concentration, and Δ p represents majority carrier concentration.
The operating principle of obtaining a photoluminescence image of a silicon carbide wafer by a photoluminescence imaging instrument is that a laser with a certain intensity is used for irradiating the silicon carbide wafer, the silicon carbide wafer absorbs photons and generates electron-hole pairs, the electron-hole pairs are in a non-equilibrium state, the electron-hole pairs are directly recombined and emit light with a certain wavelength, and the light with the certain wavelength is collected by the photoluminescence imaging instrument and converted into a numerical matrix according to the intensity of the light, so that the image is finally formed. The PL signal intensity in the PL image characterizes the electron-hole pair concentration generated by the absorption of a photon.
In this embodiment, the electron concentration in the non-equilibrium state is the minority carrier concentration, and the hole concentration in the non-equilibrium state is the majority carrier concentration.
In step S30, a carrier continuity equation is established
The carrier continuity equation describes the concentration distribution of the minority carriers generated in the silicon carbide wafer by the laser with certain intensity in the depth coordinate of the silicon carbide.
Where z represents the wafer depth coordinate, t represents time, Δ n represents the minority carrier concentration, Dn represents the minority carrier diffusion coefficient, τbRepresenting the lifetime of the silicon carbide wafer body, and G (z, t) represents the generation rate of minority carriers at a certain depth and a certain time on the silicon carbide wafer.
It should be noted that, in the equation of continuity of the carrier
Is the partial derivative of the minority carrier concentration function deltan (z, t) with time t and depth coordinate z as independent variables to time t. While
Is the second order partial derivative of the minority carrier concentration function deltan (z, t) versus the depth coordinate z with time t and depth coordinate z as arguments.
In step S40, an equation of the recombination velocity of the front surface of the sic wafer is established
Silicon carbideEquation of wafer back surface recombination velocity
Wherein z ═ 0 represents the front surface of the silicon carbide wafer, z ═ W represents the rear surface of the silicon carbide wafer, W is the depth of the silicon carbide wafer, S0Representing the front surface recombination rate of the silicon carbide wafer and Sw representing the back surface recombination rate of the silicon carbide wafer.
The equation of the recombination rate of the front surface of the silicon carbide wafer and the equation of the recombination rate of the rear surface of the silicon carbide wafer describe the condition that carriers generated by PL excitation light are recombined at the surface of the silicon carbide wafer, and the equation is a boundary condition of the distribution of the carriers on a depth coordinate.
In step S50, the PL signal intensity equation, the carrier continuity equation, the sic wafer front surface recombination rate equation, and the sic wafer back surface recombination rate equation are combined to calculate a functional relationship between the bulk lifetime of the sic wafer and the PL signal intensity.
The numerical calculation software is used as a tool, and can calculate the PL signal intensity equation, the carrier continuity equation, the silicon carbide wafer front surface recombination rate equation and the silicon carbide wafer rear surface recombination rate equation which are input into the numerical calculation software, and finally calculate the functional relation between the bulk life of the silicon carbide wafer and the PL signal intensity.
In this embodiment, MATLAB is used as numerical calculation software to perform a series of correlation numerical calculations on the above equations. In other embodiments, other numerical calculation software having the same or similar functions may be used.
In step S60, a lifetime image of the silicon carbide wafer is generated from the PL image and the functional relationship.
According to the method for generating the life image of the silicon carbide wafer body, provided that the functional relation between the body life and the PL signal intensity is obtained, the body life image of the silicon carbide wafer can be generated according to the obtained PL image of the silicon carbide wafer.
Referring to fig. 2, generating the lifetime image of the silicon carbide wafer according to the PL image and the functional relationship comprises the following steps:
step S610, acquiring a first numerical matrix, wherein the first numerical matrix is a numerical matrix of a PL image;
step S620, converting the first numerical matrix into a second numerical matrix according to the functional relation, wherein the second numerical matrix is a numerical matrix of the body life image;
and step S630, obtaining a volume lifetime image of the silicon carbide wafer according to the second numerical matrix.
In this embodiment, MATLAB is used as the numerical calculation software to obtain the life span image of the silicon carbide wafer from the second numerical matrix. In other embodiments, other numerical calculation software having the same or similar functions may be used.
In the method for generating a lifetime image of a silicon carbide wafer according to an embodiment of the present invention, the steps for generating a lifetime image of a silicon carbide wafer from a PL image and the functional relationship will be described in more detail.
In step S610, a first numerical matrix is obtained, which is a numerical matrix of the PL image.
Because the PL image is an image formed by irradiating a silicon carbide wafer with laser light of a certain intensity to generate electron-hole pairs, which are then recombined and emit light of a certain wavelength, the light of the certain wavelength is collected by a photoluminescence imaging instrument and converted into a numerical matrix according to the intensity of the light. Therefore, a corresponding first numerical matrix can also be obtained from the PL image, and the size of each numerical value in the first numerical matrix represents the distribution of PL signal intensity on the SiC wafer.
In one embodiment, the PL image is processed using MATLAB as numerical calculation software to obtain a first matrix of values in the PL image. In other embodiments, other numerical calculation software having the same or similar functions may be used.
Referring to fig. 3, in order to obtain the silicon carbide surface velocity image of a specific area or a specific size, the step S610 of obtaining the first value matrix further includes the steps of:
in step S6110, an imaging size of the silicon carbide wafer is obtained; in one embodiment, the imaging dimension refers to the dimension of a certain sub-region of the PL image, as well as the dimension of the final resulting silicon carbide surface velocity image.
In step S6120, the PL image is converted into a first numerical matrix according to the imaging size.
In step S620, the first numerical matrix is converted into a second numerical matrix according to the functional relationship between the lifetime of the silicon carbide wafer and the PL signal intensity, wherein the second numerical matrix is a numerical matrix of a volume lifetime image.
In step S630, a volume lifetime image of the silicon carbide wafer is obtained from the second numerical matrix.
In conclusion, the method can accurately measure the volume life image of the silicon carbide wafer to a greater extent, has the advantages of high imaging speed and capability of representing specific electrical parameters of the surface defects of the silicon carbide wafer, and is suitable for quality representation of the silicon carbide wafer in scientific research and industrial flow line production.
Based on the method for generating the lifetime image of the silicon carbide wafer, the embodiment of the invention further provides a system for generating the lifetime image of the silicon carbide wafer, as shown in fig. 4, the system comprises the following modules:
an image acquisition module 100 configured to acquire PL images of silicon carbide wafers.
A first equation block 200 configured to establish a PL signal intensity equation PL count ═ B Δ n Δ p, where PL count represents PL signal intensity, B represents light reflection absorption coefficient, Δ n represents minority carrier concentration, and Δ p represents majority carrier concentration.
A second equation module 300 configured to establish a carrier continuity equation
Where z represents the wafer depth coordinate, t represents time, Δ n represents the minority carrier concentration, Dn represents the minority carrier diffusion coefficient, τbThe lifetime of the silicon carbide wafer body is represented, and G (z, t) represents the generation rate of minority carriers.
A third equation block 400 configured to establish an equation for the SiC wafer front surface recombination rate
Equation of recombination velocity of rear surface of silicon carbide wafer
Wherein S0Representing the front surface recombination rate of the silicon carbide wafer and Sw representing the back surface recombination rate of the silicon carbide wafer.
The first calculation module 500 is configured to calculate a functional relationship between the lifetime of the silicon carbide wafer body and the PL signal intensity by combining the PL signal intensity equation, the carrier continuity equation, the silicon carbide wafer front surface recombination rate equation and the silicon carbide wafer rear surface recombination rate equation.
A second computing module 600 configured to generate a silicon carbide wafer bulk lifetime image from a functional relationship of bulk lifetime of the silicon carbide wafer and PL signal intensity.
Referring to fig. 5, in an embodiment, the second calculating module 600 further includes:
a matrix acquisition module 6100 configured to acquire a first numerical matrix, which is a numerical matrix of a PL image;
a matrix conversion module 6200 configured to convert the first numerical matrix into a second numerical matrix according to the functional relationship, wherein the second numerical matrix is a numerical matrix of the body life image;
an image generation module 6300 configured to obtain a volume lifetime image of the silicon carbide wafer from the second numerical matrix.
Referring to fig. 6, in an embodiment, the matrix obtaining module 6100 further includes:
a first dimension module 6110 configured to obtain an imaging dimension of the silicon carbide wafer;
a second dimension module 6120 configured to convert the PL image into a first matrix of values according to the imaged dimension.
In summary, the system for generating a lifetime image of a silicon carbide wafer according to an embodiment of the present invention may be implemented as a program running on a computer device. The memory of the computer device may store various program modules constituting the silicon carbide wafer lifetime image generating system, such as the image acquiring module 100, the first equation module 200, the second equation module 300, the third equation module 400, the first calculating module 500, and the second calculating module 600 shown in fig. 2. Each program module constitutes a program causing a processor to execute the steps in a method for generating a lifetime image of a silicon carbide wafer bulk according to each embodiment of the present application described in the present specification.
Embodiments of the present invention also provide a computer-readable storage medium, on which a computer program is stored, where the computer program, when executed by a processor, implements the steps in a method for generating a lifetime image of a silicon carbide wafer volume according to various embodiments of the present application.
The above embodiments are illustrative of the present invention, and are not intended to limit the present invention, and any simple modifications of the present invention are within the scope of the present invention. The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.
Claims (8)
1. A method for generating a lifetime image of a silicon carbide wafer body, comprising the steps of:
obtaining a PL image of the silicon carbide wafer;
establishing a PL signal intensity equation PL count ═ B Δ n Δ p, wherein PL count represents PL signal intensity, B represents light absorption reflection coefficient, Δ n represents minority carrier concentration, and Δ p represents majority carrier concentration;
establishing a carrier continuity equation
Where z represents the wafer depth coordinate, t represents time, Δ n represents the minority carrier concentration, Dn represents the minority carrier diffusion coefficient, τbRepresenting the lifetime of the silicon carbide wafer body, and G (z, t) representing the generation rate of minority carriers;
establishing a silicon carbide wafer front surface recombination velocity equation
Equation of recombination velocity of rear surface of silicon carbide wafer
Wherein z ═ 0 represents the front surface of the silicon carbide wafer, z ═ W represents the back surface of the silicon carbide wafer, W represents the depth of the silicon carbide wafer, S0Representing the front surface recombination rate of the silicon carbide wafer, and Sw representing the back surface recombination rate of the silicon carbide wafer;
combining the PL signal intensity equation, the carrier continuity equation, the SiC wafer front surface recombination rate equation and the SiC wafer rear surface recombination rate equation, and calculating to obtain a functional relation between the service life of the SiC wafer body and the PL signal intensity;
and generating a service life image of the silicon carbide wafer body according to the PL image and the functional relation.
2. The method for generating a lifetime image of a silicon carbide wafer according to claim 1, wherein said generating a lifetime image of a silicon carbide wafer from a PL image and said functional relationship comprises the steps of:
acquiring a first numerical matrix, wherein the first numerical matrix is a numerical matrix of a PL image;
converting the first numerical matrix into a second numerical matrix according to the functional relation, wherein the second numerical matrix is a numerical matrix of the body life image;
and obtaining a volume life image of the silicon carbide wafer according to the second numerical matrix.
3. The method of generating a lifetime image of a silicon carbide wafer body according to claim 2, wherein said obtaining a first matrix of values further comprises the steps of:
obtaining the imaging size of the silicon carbide wafer;
the PL image is converted to a first matrix of values based on the imaged dimensions.
4. The method of claim 1 wherein the PL image of the silicon carbide wafer is obtained by a photoluminescence imaging instrument.
5. A system for generating a lifetime image of a silicon carbide wafer body, comprising:
an image acquisition module configured to acquire a PL image of a silicon carbide wafer;
a first equation module configured to establish a PL signal intensity equation PL count ═ B Δ n Δ p, where PL count represents PL signal intensity, B represents light reflection absorption coefficient, Δ n represents minority carrier concentration, Δ p represents majority carrier concentration;
a second equation module configured to establish a carrier continuity equation
Where z represents the wafer depth coordinate, t represents time, Δ n represents the minority carrier concentration, Dn represents the minority carrier diffusion coefficient, τbRepresenting the lifetime of the silicon carbide wafer body, G (z, t) representing the minority carrierThe rate of generation of the child;
a third equation module configured to establish a SiC wafer front surface recombination velocity equation
Equation of recombination velocity of rear surface of silicon carbide wafer
Wherein S0Representing the front surface recombination rate of the silicon carbide wafer, and Sw representing the back surface recombination rate of the silicon carbide wafer;
the first calculation module is configured to simultaneously establish the PL signal intensity equation, the carrier continuity equation, the SiC wafer front surface recombination rate equation and the SiC wafer rear surface recombination rate equation, and calculate a functional relation between the service life of the SiC wafer body and the PL signal intensity;
and the second calculation module is configured to generate a silicon carbide wafer life image according to the PL image and the functional relation.
6. The silicon carbide wafer volume lifetime image generating system as claimed in claim 5, wherein said second computing module further comprises:
a matrix acquisition module configured to acquire a first numerical matrix, the first numerical matrix being a numerical matrix of a PL image;
a matrix conversion module configured to convert the first numerical matrix into a second numerical matrix according to the functional relationship, the second numerical matrix being a numerical matrix of a body life image;
an image generation module configured to obtain a volume lifetime image of the silicon carbide wafer from the second numerical matrix.
7. The silicon carbide wafer volume lifetime image generating system as claimed in claim 6, wherein said matrix acquisition module further comprises:
a first dimension module configured to obtain an imaging dimension of a silicon carbide wafer;
a second dimension module configured to convert the PL image into a first matrix of values according to the imaged dimension.
8. A computer-readable storage medium on which a computer program is stored, which when executed by a processor, implements the method for generating a lifetime image of a silicon carbide wafer volume according to any one of claims 1 to 4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111347397.8A CN114062371B (en) | 2021-11-15 | Silicon carbide wafer life image generation method, system and storage medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111347397.8A CN114062371B (en) | 2021-11-15 | Silicon carbide wafer life image generation method, system and storage medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114062371A true CN114062371A (en) | 2022-02-18 |
| CN114062371B CN114062371B (en) | 2024-07-12 |
Family
ID=
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002083852A (en) * | 2000-09-08 | 2002-03-22 | Mitsubishi Materials Silicon Corp | Quality evaluation method of silicon wafer |
| CN102393503A (en) * | 2011-11-14 | 2012-03-28 | 北京航空航天大学 | GaAs solar energy cell performance degeneration prediction method in space environment |
| CN102483378A (en) * | 2009-07-20 | 2012-05-30 | Bt成像股份有限公司 | Separation Of Doping Density And Minority Carrier Lifetime In Photoluminescence Measurements On Semiconductor Materials |
| CN104025276A (en) * | 2011-11-07 | 2014-09-03 | Bt成像股份有限公司 | Wafer grading and sorting for photovoltaic cell manufacture |
| CN104282593A (en) * | 2013-07-03 | 2015-01-14 | 塞米拉布Sdi有限责任公司 | Photoluminescence mapping of passivation defects for silicon photovoltaics |
| CN112432936A (en) * | 2020-11-06 | 2021-03-02 | 电子科技大学 | Rapid quantitative imaging characterization method for life space distribution of semiconductor wafer excess carriers |
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002083852A (en) * | 2000-09-08 | 2002-03-22 | Mitsubishi Materials Silicon Corp | Quality evaluation method of silicon wafer |
| CN102483378A (en) * | 2009-07-20 | 2012-05-30 | Bt成像股份有限公司 | Separation Of Doping Density And Minority Carrier Lifetime In Photoluminescence Measurements On Semiconductor Materials |
| CN106932369A (en) * | 2009-07-20 | 2017-07-07 | Bt成像股份有限公司 | Doping concentration and minority carrier lifetime are separated in photoluminescence measurement |
| CN104025276A (en) * | 2011-11-07 | 2014-09-03 | Bt成像股份有限公司 | Wafer grading and sorting for photovoltaic cell manufacture |
| CN102393503A (en) * | 2011-11-14 | 2012-03-28 | 北京航空航天大学 | GaAs solar energy cell performance degeneration prediction method in space environment |
| CN104282593A (en) * | 2013-07-03 | 2015-01-14 | 塞米拉布Sdi有限责任公司 | Photoluminescence mapping of passivation defects for silicon photovoltaics |
| CN112432936A (en) * | 2020-11-06 | 2021-03-02 | 电子科技大学 | Rapid quantitative imaging characterization method for life space distribution of semiconductor wafer excess carriers |
Non-Patent Citations (2)
| Title |
|---|
| 刘俊岩 等: "调制激光致硅晶圆载流子辐射扫描成像试验研究", 物理学报, vol. 64, no. 8, 16 March 2015 (2015-03-16), pages 087804 * |
| 宋鹏: "硅晶圆/硅太阳能电池主要特性参数的PCR/LIPL检测技术研究", 中国博士论文全文数据库, no. 01, 15 January 2020 (2020-01-15), pages 16 - 39 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Isenberg et al. | Imaging method for laterally resolved measurement of minority carrier densities and lifetimes: Measurement principle and first applications | |
| Gundel et al. | Quantitative carrier lifetime measurement with micron resolution | |
| Giesecke et al. | Determination of local minority carrier diffusion lengths in crystalline silicon from luminescence images | |
| WO2020009011A1 (en) | Optical distance measuring apparatus | |
| CN102859338A (en) | Time Resolved Photoluminescence Imaging Systems And Methods For Photovoltaic Cell Inspection | |
| JP5843114B2 (en) | Method and apparatus for measuring carrier lifetime | |
| CN108240867B (en) | High frequency phase-locked thermography using single photon detectors | |
| JP2010091377A (en) | Apparatus and method for optical distance measurement | |
| JP2010091378A (en) | Image acquisition device and method of acquiring image | |
| TWI595227B (en) | Semiconductor element inspection apparatus and semiconductor element inspection method | |
| WO2010019992A1 (en) | Method and apparatus for defect detection | |
| Höffler et al. | Review and recent development in combining photoluminescence-and electroluminescence-imaging with carrier lifetime measurements via modulated photoluminescence at variable temperatures | |
| CN113781487B (en) | Method and system for generating SiC wafer surface recombination velocity image and storage medium | |
| US10012593B2 (en) | Micro photoluminescence imaging | |
| Sio et al. | Quantifying carrier recombination at grain boundaries in multicrystalline silicon wafers through photoluminescence imaging | |
| US10302574B2 (en) | Method for analysing the crystal structure of a polycrystalline semiconductor | |
| Savuskan et al. | An estimation of single photon avalanche diode (SPAD) photon detection efficiency (PDE) nonuniformity | |
| Giesecke et al. | Separation of local bulk and surface recombination in crystalline silicon from luminescence reabsorption | |
| CN114354651A (en) | Optical detection device, signal-to-noise ratio estimation method and defect detection method | |
| CN114062371A (en) | Method and system for generating life image of silicon carbide wafer body and storage medium | |
| CN114062371B (en) | Silicon carbide wafer life image generation method, system and storage medium | |
| Wang et al. | An FPGA-based real-time maximum likelihood 3D position estimation for a continuous crystal PET detector | |
| WO2010110751A1 (en) | System and method for determining surface recombination velocity | |
| CN111128783A (en) | Longitudinal distribution test system and method for minority carrier lifetime | |
| US20230282526A1 (en) | Method and device for measuring the thickness of thin films even on rough substrates |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant |