CN110514627B - Silicon wafer reflectivity measuring method and measuring device thereof - Google Patents
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- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 title claims abstract description 89
- 229910052710 silicon Inorganic materials 0.000 title claims abstract description 89
- 239000010703 silicon Substances 0.000 title claims abstract description 89
- 238000002310 reflectometry Methods 0.000 title claims abstract description 84
- 238000000034 method Methods 0.000 title claims abstract description 32
- 238000012360 testing method Methods 0.000 claims abstract description 62
- 238000001228 spectrum Methods 0.000 claims abstract description 39
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- 238000005259 measurement Methods 0.000 claims description 37
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- 229910052736 halogen Inorganic materials 0.000 claims description 3
- 150000002367 halogens Chemical class 0.000 claims description 3
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- 238000007650 screen-printing Methods 0.000 claims description 3
- 238000004088 simulation Methods 0.000 claims description 3
- 229910052724 xenon Inorganic materials 0.000 claims description 3
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 0.000 claims description 3
- 238000009792 diffusion process Methods 0.000 claims description 2
- 239000007888 film coating Substances 0.000 claims description 2
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- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 7
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- 239000013078 crystal Substances 0.000 description 5
- 229910021421 monocrystalline silicon Inorganic materials 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 4
- 239000013307 optical fiber Substances 0.000 description 4
- 229920005591 polysilicon Polymers 0.000 description 4
- 238000010998 test method Methods 0.000 description 4
- 238000000691 measurement method Methods 0.000 description 3
- 241000227425 Pieris rapae crucivora Species 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
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- 239000000843 powder Substances 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000002798 spectrophotometry method Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
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Abstract
The invention discloses a silicon wafer reflectivity measuring method, which comprises the following steps: (1) Uniformly irradiating the surface of the silicon wafer sample by using a light source with a specific spectrum; (2) Focusing light reflected by the surface of the silicon wafer sample onto a photoelectric detector through an optical lens; (3) The optical signal received by the photoelectric detector is converted into an electric signal, and the result is output; (4) And comparing the output result with the test result of the standard sample to obtain the reflectivity of the silicon wafer sample to be tested. The invention also discloses a silicon wafer reflectivity measuring device which has reasonable overall structural design, can accurately and rapidly measure the silicon wafer reflectivity, avoids the difference of subjective judgment, has high speed, high precision and high repeatability, can measure the silicon wafer reflectivity in a large area, realizes batch detection, has wide application range and lower cost, and is favorable for wide popularization and application.
Description
Technical Field
The invention relates to the technical field of silicon wafer reflectivity detection, in particular to a silicon wafer reflectivity measurement method and a silicon wafer reflectivity measurement device.
Background
At present, the measuring method of the reflectivity of the silicon wafer mainly comprises two methods, wherein the main difference is that the positions of the light splitting are different, one method is to split light before a test sample, and the other method is to split light after the test sample. The first method is that the grating is used to divide the light of the light source into a spectrum, the spectrum irradiates the slit to generate monochromatic light, the monochromatic light irradiates the sample to be measured with a certain small included angle (8 DEG conventionally) after collimation and other operations, the light reflected by the sample is integrated in the integrating sphere, and the energy of the whole reflected light is calculated by detecting the local light intensity by the photoelectric detector on the side wall of the integrating sphere. Finally, the reflectivity of the sample at the wavelength is obtained through the ratio of the reflected energy to the incident energy. The energy of the incident light is calculated from the reflectance and the reflected energy of the standard sample. Different incident wavelengths can be obtained by changing the inclination angle of the grating. The reflectivity of a single point of the sample is obtained by integrating the reflectivity at each wavelength with the standard spectrum of sunlight. It takes seconds or even minutes to measure the entire spectrum to obtain the average reflectivity of a single point sample. The measured area is determined by the spot size and the final measured reflectivity is the average reflectivity of the entire spot area. Therefore, the technology cannot obtain the reflectivity smaller than the spot area, and cannot obtain the reflectivity of a large area. Even if the sweep measurement is performed on the entire area, the entire area is approximated by only a method of acquiring a plurality of points, which also requires a lot of time. This solution is disadvantageous for industrial applications, since it takes a lot of time both in terms of grating movement and position-by-position measurement, and is only used in laboratories.
The other scheme is that a light source with a wide spectrum is converged through a lens and irradiates the inside of the integrating sphere from the side, and the optical fiber at the position of 8 degrees from the top records the change of light intensity at different wavelengths when a sample exists at the bottom and when a standard sample exists at the bottom, so that the reflectivity at different wavelengths is obtained. Wherein the light guided out of the optical fiber enters the optical fiber spectrometer for analysis. Because the grating in the optical fiber spectrometer is a fixed grating, the time consumed by the movement of the grating is avoided by a method of analyzing the grating by a CCD with one length. However, the test area of this scheme is determined by the open pore on the integrating sphere, and no reflection in the smaller area than the pore can be obtained. The same problem exists as in the first solution if a large area needs to be tested. Considerable time is required, so there are still significant problems with the use in industry. In particular for non-uniform samples, to obtain a more accurate reflectivity, it is necessary to obtain it by taking an average value through multipoint measurement. But the difference in each selected spot results in very poor repeatability of the reflectivity test results. If it is desired to improve repeatability, the number of measurement points needs to be increased, thus increasing the time cost of the measurement, and thus the balance between repeatability and accuracy and time needs to be maintained.
The publication number CN107845090A, named as a silicon wafer detection method and a silicon wafer detection device, discloses a silicon wafer detection method, and a method for measuring the reflectivity by using the relation between the gray value of each pixel point of a silicon wafer and the reflectivity of the silicon wafer. However, the accuracy of the measurement result of the method is sufficiently dependent on the correlation of the gray value and the reflectivity, and in order to improve the accuracy of the test, one type of sample needs to be calibrated by using the same type of sample to obtain a more accurate result. Because the testing of this method, while increasing the area of the test and reducing the test time, sacrifices the accuracy of the test and the versatility of device calibration.
Therefore, there is an urgent need for a silicon wafer reflectivity measurement method and measurement apparatus that are more accurate and have a short measurement time, and that can measure the reflectivity of a large area silicon wafer.
Disclosure of Invention
In view of the above-mentioned shortcomings, an object of the present invention is to provide a method and an apparatus for measuring reflectance of a silicon wafer.
In order to achieve the above purpose, the technical scheme provided by the invention is as follows:
a silicon wafer reflectivity measuring method comprises the following steps:
(1) Uniformly irradiating the surface of the silicon wafer sample by using a light source with a specific spectrum;
(2) Focusing light reflected by the surface of the silicon wafer sample onto a photoelectric detector through an optical lens;
(3) The optical signal received by the photoelectric detector is converted into an electric signal, and the result is output;
(4) And comparing the output result with the test result of the standard sample to obtain the reflectivity of the silicon wafer sample to be tested.
As an improvement of the invention, the light source is a light source with the spectral responsivity of the photoelectric detector compensated, and the specific spectrum of the light source is 400-500nm, 500-600nm, 600-700nm, 700-800nm, 800-900nm and 900-1100nm, and the ratio of the percentage of the total irradiance actually tested in the six wavelength ranges to the percentage of the ideal spectral irradiance distribution is between 0.4 and 2.0; the product of the spectrum of the ideal light source and the responsivity of the used photoelectric detector is the standard AM1.5 spectrum of sunlight multiplied by a constant.
As an improvement of the present invention, the photodetector includes a CCD or a CMOS; the light source is formed by combining one or more of an LED, a xenon lamp and a halogen lamp. The silicon wafer sample is a silicon wafer which is subjected to original cutting, texturing, polishing, diffusion, film coating, screen printing, solar cell finished product or other products made of the silicon wafer.
As an improvement of the present invention, the step (4) is calculated using the following formula: r=r0/i0×i+b;
Wherein R is the reflectivity of a silicon wafer sample, R0 is the reflectivity of a standard sample, I0 is the photo-generated current after the measurement of the standard sample, I is the photo-generated current after the measurement of a sample to be measured, and b is a correction factor.
As an improvement of the present invention, the output result in the step (3) is a gray value, and the gray value is proportional to the magnitude of the photoelectric current.
As an improvement of the present invention, the step (4) is calculated using the following formula: r=r0/h0 h+b;
Wherein R is the reflectivity of a silicon wafer sample, R0 is the reflectivity of a standard sample, H0 is the gray value measured by the standard sample, H is the gray value measured by a sample to be measured, and b is a correction factor.
The utility model provides a silicon chip reflectivity measuring device, its includes sample platform, light source module, optical lens module, data acquisition module and data analysis operation module, the sample platform sets up the bottom surface in the sealed box, optical lens module and data acquisition module combine together to form the camera lens, and this camera lens sets up the top surface in the sealed box, light source module sets up in the box, and towards the sample platform. The sample stage is used for placing a silicon wafer sample to be tested; the light source module is used for providing a uniform light source with a specific spectrum for a silicon wafer sample placed on the sample stage; the optical lens module is used for converging the light reflected by the silicon wafer sample and filtering out non-reflected light; the data acquisition module is used for converting the optical signals converged by the optical lens into electric signals and outputting the results. The data analysis operation module is used for comparing the output result of the data acquisition module with the test result of the standard sample to obtain the reflectivity of the silicon wafer sample.
As an improvement of the invention, the light source module is a sunlight simulation light source after compensating the spectral response of the photoelectric detector, the data acquisition module is a photoelectric detector which is arranged singly or in an array, and the photoelectric detector is CCD or CMOS.
Since the solar cell is used in the sunlight environment, the reflectance of the silicon wafer for the solar cell needs to be measured by taking the solar spectrum into consideration. The reflectivity measurement of the current silicon wafer is to perform weighted summation on the reflectivity of the solar spectrum at each wavelength between lambda 1 and lambda 2 according to the following formula, so as to obtain the reflectivity R of a measurement area:
Where G (lambda) is the AM1.5 standard spectrum of sunlight, lambda 1 and lambda 2 are the start and end wavelengths of the test respectively, typically 300nm and 1100nm respectively. The calculation method requires knowing the reflectance of each wavelength in the continuous spectrum between λ1 and λ2 and then integrating to obtain the average reflectance R. The current method for measuring the reflectivity of the silicon wafer is to measure the reflectivity R (lambda) of each wavelength lambda once, but in the practical testing process, for the first testing method, the reflectivity at partial wavelengths can be measured only according to a specific step length due to the limitation of the movement precision and the testing time of the grating, and the average reflectivity is obtained by a direct-substitution method, wherein the common step length is selected to be 20nm, 10nm, 1nm and the like, so that the error of the reflectivity measurement result can be caused.
Publication number "CN107845090a", entitled "a silicon wafer detection method and a silicon wafer detection apparatus", discloses a silicon wafer detection method, the method used is to consider the entire spectrum situation, so for each pixel point, the calculation formula of the reflectivity R (x, y) is:
Where G LED (λ) is the LED spectrum used, and this measurement method causes a large error because the LED spectrum is very different from the solar spectrum. The reflectivity can thus only be calculated using the linear relation of the gray value and the reflectivity, while some errors of the measurement can be reduced, there are still large errors. And it is apparent that there is a significant difference in the slope of the gray value versus the reflectance for different types of silicon wafer samples, so that calibration using the same type of silicon wafer is required for each silicon wafer type to reduce the measurement error of the reflectance.
The beneficial effects of the invention are as follows: the silicon wafer reflectivity detection method provided by the invention can quantify the appearance condition of the silicon wafer, avoids the difference of subjective judgment, and has the advantages of high speed, high precision and high repeatability; the silicon wafer reflectivity measuring device provided by the invention has the advantages of reasonable structure, simple hardware configuration, high working reliability, capability of accurately and rapidly measuring the silicon wafer reflectivity, capability of measuring the silicon wafer reflectivity in a large area, wide application range, low cost and contribution to wide popularization and application.
The invention will be further described with reference to the drawings and examples.
Drawings
FIG. 1 is a schematic diagram of a silicon wafer reflectivity measuring mechanism.
Fig. 2 is the responsivity of a CMOS photodetector.
FIG. 3 is a diagram of an ideal light source spectrum.
Detailed Description
Referring to fig. 1 to 3, the method for measuring reflectivity of a silicon wafer according to the present embodiment includes the following steps:
(1) Uniformly irradiating a surface of a silicon wafer sample by using a sunlight-simulated light source after compensating the spectral response of the photoelectric detector; the specific spectrum of the light source is selected from 400-500nm, 500-600nm, 600-700nm, 700-800nm, 800-900nm and 900-1100nm. The ratio of the percentage of total irradiance actually tested for these six wavelength ranges to the percentage of the ideal spectral irradiance distribution is between 0.4 and 2.0. The product of the spectrum of the ideal light source and the responsivity of the used photoelectric detector is the standard AM1.5 spectrum of sunlight multiplied by a constant. The solar simulation light source is formed by combining one or more of an LED, a xenon lamp and a halogen lamp to emit light. The light of the light source can uniformly irradiate the surface of the silicon wafer sample at any angle; the silicon wafer sample is a silicon wafer, a solar cell finished product or other products made of the silicon wafer after original cutting, texturing, polishing, diffusing, coating, screen printing;
(2) Focusing light reflected by the surface of the silicon wafer sample onto a photoelectric detector through an optical lens; the photoelectric detector comprises a CCD or a CMOS;
(3) The optical signal received by the photoelectric detector is converted into an electric signal, and the result is output;
(4) And comparing the output result with the test result of the standard sample to obtain the reflectivity of the silicon wafer sample to be tested. Specifically, the step (4) is calculated by adopting the following formula: r=r0/i0×i+b; wherein R is the reflectivity of a silicon wafer sample, R0 is the reflectivity of a standard sample, I0 is the photo-generated current after the measurement of the standard sample, I is the photo-generated current after the measurement of a sample to be measured, and b is a correction factor.
Or, when the output result in the step (3) is a gray value, the gray value is proportional to the magnitude of the photoelectric current. The step (4) adopts the following formula to calculate: r=r0/h0 h+b; wherein R is the reflectivity of a silicon wafer sample, R0 is the reflectivity of a standard sample, H0 is the gray value measured by the standard sample, H is the gray value measured by a sample to be measured, and b is a correction factor.
The device for measuring the reflectivity of the silicon wafer comprises a sample stage 1, a light source module 2, an optical lens module 3, a data acquisition module and a data analysis operation module 4. In this embodiment, the data analysis and operation module 4 is a desktop computer. In other embodiments, the data analysis and operation module 4 may be an industrial personal computer.
The sample platform 1 sets up the bottom surface in the sealed box, optical lens module 3 and data acquisition module combine together to form camera lens 3, and this camera lens 3 sets up the top surface in the sealed box, light source module 2 sets up in the box, and the selection of light source needs to consider the light source and can evenly shine the sample surface with the multi-angle.
The sample stage 1 is used for placing a silicon wafer sample to be tested; the light source module 2 is used for providing a uniform multi-angle light source with a specific spectrum for a silicon wafer sample placed on the sample stage 1; the optical lens module 3 is used for converging the light reflected by the silicon wafer sample and filtering out non-reflected light; the data acquisition module is used for converting the optical signals converged by the optical lens into electric signals and outputting the results. The data analysis operation module 4 is used for comparing the output result of the data acquisition module with the test result of the standard sample to obtain the reflectivity of the silicon wafer sample.
Standard measurement: the step length of the wavelength is 0.1nm by using a spectrophotometry test method, wherein samples 1,2,3 and 4 are monocrystalline silicon wafer samples which are uniform as a whole, and samples 5 and 6 are polycrystalline silicon wafer samples with different crystal grains on the surfaces. For a monocrystalline silicon sample, the surface uniformity is good, and an accurate and reliable reflectivity result can be obtained by adopting a 25-point test with the test time of 900 s. For a polysilicon sample, there are different grains on the surface, so the reflectivity of different regions is quite different. The number of test points is 100 points, and the test time is 3000s. Because the test step length is shorter and the multi-point test is needed to improve the test accuracy, the spectrophotometer test method needs longer test time and is not suitable for mass industrial production.
Example 1:
The LED lamp with the spectrum of 400-500nm, 500-600nm, 600-700nm, 700-800nm, 800-900nm and 900-1100nm, which are the ratios of the percentage of the total irradiance actually tested to the percentage of the ideal spectral irradiance distribution of 0.92, 0.90, 0.79, 1.08, 1.03 and 1.13, respectively, was used as a light source. The ideal spectrum is shown as a CMOS photodetector 1 shown in fig. 3, and the CMOS photodetector 1 is used as the photodetector, and the spectral responsivity is shown as fig. 2. The photoelectric sensor is used for converting the light energy collected by the lens into a current signal, and the current test result is compared with the result of a standard silicon wafer to obtain the test results of the following six samples, and the specific reference is shown in table 1.
TABLE 1
| Sample numbering | Standard measurement | Example 1 | Differences in |
| 1 | 8.10％ | 8.28％ | 0.18％ |
| 2 | 8.88％ | 9.03％ | 0.15％ |
| 3 | 30.27％ | 30.17％ | 0.10％ |
| 4 | 11.33％ | 11.40％ | 0.07％ |
| 5 | 18.03％ | 18.33％ | 0.30％ |
| 6 | 22.97％ | 23.01％ | 0.04％ |
Compared with the standard measurement result, the difference rate is between 0.3 percent, the reflectivity error of the monocrystalline silicon sample is 0.2 percent, and the reflectivity difference of the polycrystalline silicon sample is between 0.3 percent, which fully indicates that the method can indicate the reflectivity and indicates the accuracy of the test mode result. The test method has the advantages that the test time is the same for a single crystal sample or a polycrystalline sample, only 1s is needed, and the accurate test result can be obtained under the condition of accurate test result.
Example 2:
The LED lamp sunlight simulator which compensates the spectrum response of the photoelectric detector and simulates the sunlight is used as a light source, and the ratio of the percentage of the total irradiance actually tested in the six wavelength ranges of 400-500nm, 500-600nm, 600-700nm, 700-800nm, 800-900nm and 900-1100nm to the percentage of the ideal spectrum irradiation distribution is 0.95, 0.78, 0.73, 0.83, 1.03 and 1.45 respectively. The light energy collected by the lens is converted into a current signal by using the array of the CCD photoelectric detector 2, and the current test result is compared with the result of a standard silicon wafer to obtain the test results of the following six samples, and the specific reference is shown in Table 2.
TABLE 2
| Sample numbering | Standard measurement | Example 2 | Differences in |
| 1 | 8.10％ | 8.27％ | 0.17％ |
| 2 | 8.68％ | 8.74％ | 0.06％ |
| 3 | 30.27％ | 30.02％ | 0.25％ |
| 4 | 11.33％ | 11.20％ | 0.13％ |
| 5 | 18.03％ | 18.50％ | 0.47％ |
| 6 | 22.97％ | 22.97％ | 0.00％ |
Compared with the standard measurement result, the difference rate is between 0.5%, the reflectivity error of the monocrystalline silicon sample is 0.25%, and the reflectivity difference of the polycrystalline silicon sample is between 0.5%, so that the method can fully show the reflectivity, and the accuracy of the test mode result is shown.
Since the spectrum is less matched to the ideal spectrum than in example 1, the accuracy of the results is slightly lower. The test time is the same for either single crystal or polycrystalline samples, requiring only 1s.
Comparative example 1:
A common white light LED is used as a light source, and the LED emits white light under the action of fluorescent powder. The light energy collected by the lens is converted into a current signal by using a CMOS photoelectric detector, and the current test result is compared with the result of a standard silicon wafer to obtain the test results of the following six samples, and the test results are specifically shown in Table 3.
TABLE 3 Table 3
| Sample numbering | Standard measurement | Comparative example 1 | Differences in |
| 1 | 8.10％ | 9.41％ | 1.31％ |
| 2 | 8.68％ | 8.54％ | 0.14％ |
| 3 | 30.27％ | 31.09％ | 0.82％ |
| 4 | 11.33％ | 11.98％ | 0.65％ |
| 5 | 18.03％ | 19.56％ | 1.53％ |
| 6 | 22.97％ | 26.40％ | 3.43％ |
Compared with standard measurement results, the difference rate of part of samples is more than 1%, and even one polycrystalline sample has the difference rate of 3.43%. The use of a conventional white LED as a light source introduces a large error. But for samples where the reflectance does not vary much with wavelength, the accuracy of the test results may be less than 0.5%, so a common white LED light source may be used for measurement of the reflectance of a particular sample, but is not generic and requires calibration with this type of silicon wafer for each type of silicon wafer. Also the test method is identical for test time, whether for single crystal or polycrystalline samples, requiring only 1s.
Comparative example 2:
The step sizes of the wavelengths are 10nm,20nm and 40nm respectively, the surface uniformity of the single crystal silicon samples 1,2, 3 and 4 is good, and the 9-point test is adopted, so that the test time is 460s, 390s and 330s respectively. For polysilicon samples 5 and 6, there are different grains on the surface, so the reflectivity of the different regions is quite different. The number of test points is 100, and the test time is 2500s, 2330s and 1900s respectively. The test results are specifically shown in table 4;
TABLE 4 Table 4
Compared with the standard measurement result, the step length of the test wavelength is increased, the difference of the measurement result is increased while the test time is reduced, and the difference rate reaches 0.2% when the step length is 40 nm. Even when the step size is increased, the test time is still long, and the use of industrial production cannot be satisfied, and particularly for polysilicon, a very large number of measurement points are required to obtain accurate results.
Comparative example 3 measurement was performed by using the method of post-sample spectroscopic test, the step size of the wavelength was selected to be 10nm, and the samples were tested at 5, 25 and 64 points, with test times of 26s, 65s and 110s, respectively. The test results are specifically shown in table 5;
TABLE 5
Compared with the standard measurement result, the number of test points is reduced, the purpose of reducing the test time can be achieved, but the difference of the measurement result is increased. When the number of test points is reduced to 5 points, although the time is reduced to 26s, the difference rate exceeds 5%, mainly due to the difference of the reflectivity of the polysilicon on different crystal directions. And the result difference caused by different test directions is also very large. Increasing the number of test points, it is possible to significantly find out that the rate of difference of the test results is decreasing, so that as many measurement points as possible are needed if an accurate result is desired, but this significantly increases the test time.
Therefore, the invention provides a method for measuring the reflectivity by utilizing the simulated light source and the photoelectric detector after compensating the spectral response of the photoelectric detector according to the reflectivity measurement formula, and the method not only can reduce the measurement time, but also can obtain accurate test results in any area.
Variations and modifications to the above would be obvious to persons skilled in the art to which the invention pertains from the foregoing description and teachings. Therefore, the invention is not limited to the specific embodiments disclosed and described above, but some modifications and changes of the invention should be also included in the scope of the claims of the invention. In addition, although specific terms are used in the present specification, these terms are for convenience of description only and do not limit the present invention in any way. Other methods and apparatus using the same or similar steps as described in the above embodiments of the invention are within the scope of the invention.
Claims (7)
1. A silicon wafer reflectivity measuring method is characterized in that: which comprises the following steps:
(1) Uniformly irradiating the surface of the silicon wafer sample by using a light source with a specific spectrum;
(2) Focusing light reflected by the surface of the silicon wafer sample onto a photoelectric detector through an optical lens;
(3) The optical signal received by the photoelectric detector is converted into an electric signal, and the result is output;
(4) Comparing the output result with the test result of the standard sample to obtain the reflectivity of the silicon wafer sample to be tested;
The specific spectrum of the light source is 400-500nm, 500-600nm, 600-700nm, 700-800nm, 800-900nm and 900-1100nm, and the ratio of the percentage of the total irradiance actually tested in the six wavelength ranges to the percentage of the ideal spectrum irradiation distribution is 0.4-2.0; the product of the ideal spectrum and the responsivity of the photodetector used is the standard AM1.5 spectrum of sunlight multiplied by a constant.
2. The method for measuring the reflectivity of a silicon wafer according to claim 1, wherein: the photoelectric detector comprises a CCD or a CMOS; the light source is formed by combining one or more of an LED, a xenon lamp and a halogen lamp.
3. The method for measuring the reflectivity of a silicon wafer according to claim 1, wherein: the silicon wafer sample is a silicon wafer which is subjected to original cutting, texturing, polishing, diffusion, film coating, screen printing, solar cell finished product or other products made of the silicon wafer.
4. The method for measuring the reflectivity of a silicon wafer according to claim 1, wherein: the step (4) adopts the following formula to calculate: r=r0/i0×i+b;
Wherein R is the reflectivity of a silicon wafer sample, R0 is the reflectivity of a standard sample, I0 is the photo-generated current after the measurement of the standard sample, I is the photo-generated current after the measurement of a sample to be measured, and b is a correction factor.
5. The method for measuring the reflectivity of a silicon wafer according to claim 1, wherein: the output result in the step (3) is a gray value, and the gray value is proportional to the magnitude of the photo-generated current.
6. The method for measuring the reflectivity of a silicon wafer according to claim 5, wherein: the step (4) adopts the following formula to calculate: r=r0/h0 h+b;
Wherein R is the reflectivity of a silicon wafer sample, R0 is the reflectivity of a standard sample, H0 is the gray value measured by the standard sample, H is the gray value measured by a sample to be measured, and b is a correction factor.
7. A silicon wafer reflectivity measuring device is characterized by comprising
The sample stage is used for placing a silicon wafer sample to be tested;
The light source module is used for providing a uniform light source with a specific spectrum for the silicon wafer sample placed on the sample stage;
the optical lens module is used for converging the light reflected by the silicon wafer sample and filtering out non-reflected light;
the data acquisition module is used for converting the optical signals converged by the optical lens into electric signals and outputting the results; the data acquisition module is a photoelectric detector which is arranged singly or in an array, and the photoelectric detector is a CCD or a CMOS;
the data analysis operation module is used for comparing the output result of the data acquisition module with the test result of the standard sample to obtain the reflectivity of the silicon wafer sample;
the light source module is a sunlight simulation light source with the spectral response of the photoelectric detector compensated, the specific spectrum of the light source is 400-500nm, 500-600nm, 600-700nm, 700-800nm, 800-900nm and 900-1100nm, and the ratio of the percentage of the total irradiance actually tested in the six wavelength ranges to the percentage of the ideal spectral irradiation distribution is between 0.4 and 2.0; the product of the ideal spectrum and the responsivity of the used photoelectric detector is the standard AM1.5 spectrum of sunlight multiplied by a constant.
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Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004070363A1 (en) * | 2003-02-03 | 2004-08-19 | Beaglehole Instruments Ltd | Sample container |
| CN101169602A (en) * | 2007-11-30 | 2008-04-30 | 北京理工大学 | Focusing leveling measuring method and device |
| US8066681B1 (en) * | 1989-10-11 | 2011-11-29 | Edwards Life Sciences, Inc. | Intracranial pressure monitor and drainage catheter assembly |
| CN103105286A (en) * | 2013-01-24 | 2013-05-15 | 中国兵器工业第二〇五研究所 | Imaging optoelectronic system spectral response heterogeneity measuring method |
| CN103512864A (en) * | 2012-06-25 | 2014-01-15 | 中国科学院微电子研究所 | Optical measuring system for measuring reflectivity and transmittivity of substrate by utilizing parallel light |
| CN203502579U (en) * | 2013-07-12 | 2014-03-26 | 应用材料意大利有限公司 | System used for calibrating light source capable of simulating solar radiation spectrum |
| CN104992990A (en) * | 2010-12-30 | 2015-10-21 | 中国科学院物理研究所 | Method for reducing light reflectivity of surface of silicon chip |
| WO2017098053A1 (en) * | 2015-12-11 | 2017-06-15 | Dsm Ip Assets B.V. | System and method for optical measurements on a transparent sheet |
| CN107845090A (en) * | 2017-10-27 | 2018-03-27 | 中国科学院物理研究所 | A kind of silicon chip detection method and silicon chip detection means |
| CN108321094A (en) * | 2017-12-21 | 2018-07-24 | 河源市众拓光电科技有限公司 | The method of raising light emitting diode (LED) chip with vertical structure reflectance of reflector based on stress regulation and control |
| CN108615776A (en) * | 2018-04-26 | 2018-10-02 | 中国科学院物理研究所 | Deflection surfaces structure and corresponding preparation method |
| CN108761300A (en) * | 2018-06-22 | 2018-11-06 | 中国计量大学 | External quantum efficiency of solar battery fast testing system based on frequency division multiplexing and method |
| CN109115730A (en) * | 2018-11-02 | 2019-01-01 | 天津津航技术物理研究所 | Spectral transmittance test macro and method based on tunable laser |
| CN211179528U (en) * | 2019-08-26 | 2020-08-04 | 松山湖材料实验室 | Silicon chip reflectivity measuring device |
-
2019
- 2019-08-26 CN CN201910791330.XA patent/CN110514627B/en active Active
Patent Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8066681B1 (en) * | 1989-10-11 | 2011-11-29 | Edwards Life Sciences, Inc. | Intracranial pressure monitor and drainage catheter assembly |
| WO2004070363A1 (en) * | 2003-02-03 | 2004-08-19 | Beaglehole Instruments Ltd | Sample container |
| CN101169602A (en) * | 2007-11-30 | 2008-04-30 | 北京理工大学 | Focusing leveling measuring method and device |
| CN104992990A (en) * | 2010-12-30 | 2015-10-21 | 中国科学院物理研究所 | Method for reducing light reflectivity of surface of silicon chip |
| CN103512864A (en) * | 2012-06-25 | 2014-01-15 | 中国科学院微电子研究所 | Optical measuring system for measuring reflectivity and transmittivity of substrate by utilizing parallel light |
| CN103105286A (en) * | 2013-01-24 | 2013-05-15 | 中国兵器工业第二〇五研究所 | Imaging optoelectronic system spectral response heterogeneity measuring method |
| CN203502579U (en) * | 2013-07-12 | 2014-03-26 | 应用材料意大利有限公司 | System used for calibrating light source capable of simulating solar radiation spectrum |
| WO2017098053A1 (en) * | 2015-12-11 | 2017-06-15 | Dsm Ip Assets B.V. | System and method for optical measurements on a transparent sheet |
| CN107845090A (en) * | 2017-10-27 | 2018-03-27 | 中国科学院物理研究所 | A kind of silicon chip detection method and silicon chip detection means |
| CN108321094A (en) * | 2017-12-21 | 2018-07-24 | 河源市众拓光电科技有限公司 | The method of raising light emitting diode (LED) chip with vertical structure reflectance of reflector based on stress regulation and control |
| CN108615776A (en) * | 2018-04-26 | 2018-10-02 | 中国科学院物理研究所 | Deflection surfaces structure and corresponding preparation method |
| CN108761300A (en) * | 2018-06-22 | 2018-11-06 | 中国计量大学 | External quantum efficiency of solar battery fast testing system based on frequency division multiplexing and method |
| CN109115730A (en) * | 2018-11-02 | 2019-01-01 | 天津津航技术物理研究所 | Spectral transmittance test macro and method based on tunable laser |
| CN211179528U (en) * | 2019-08-26 | 2020-08-04 | 松山湖材料实验室 | Silicon chip reflectivity measuring device |
Non-Patent Citations (8)
| Title |
|---|
| A 级太阳模拟器的光谱校正;彭小静等;《太阳能学报》;20081130;第29卷(第11期);1324-1327 * |
| Designable dual-material auxetic metamaterials using three-dimensional printing;Wang, K et al;《MATERIALS & DESIGN》;20150215;第67卷;159-164 * |
| Optical properties of a random inverted pyramid textured silicon surface studied by the ray tracing method;Chen, QS et al;《SOLAR ENERGY》;20190625;第186卷;392-397 * |
| 不同硅晶面指数上的类倒金字塔结构研究与分析;陈全胜等;《物理学报》;20181113;第67卷(第22期);384-392 * |
| 图像法测定煤岩组分反射率工作曲线的建立与应用;陈洪博等;《煤炭学报》;20140331;第39卷(第3期);562-567 * |
| 基于数字图像的多孔硅微阵列中折射率变化的并行检测;李传喜;《中国优秀硕士学位论文全文数据库 (工程科技Ⅰ辑)》;20181215(第12期);B015-115 * |
| 氧化锌基材料、异质结构及光电器件;申德振等;《发光学报》;20140114;第35卷(第1期);1-60 * |
| 胡毅等.《光有源器件原来与技术》.北京：北京邮电大学出版社,2016,(第第一版版),70-72. * |
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