SJ 3248-1989 Infrared reflection test method for carrier concentration of heavily doped gallium arsenide and indium phosphide SJ3248-1989 standard download decompression password: www.bzxz.net

Standard of the Ministry of Machinery and Electronics Industry of the People's Republic of China Infrared Reflection Test Method for Carrier Concentration of Heavily Doped Gallium Arsenide and Indium Phosphide
Subject Content and Scope of Application
SJ3248-89
This standard specifies the measurement principle, instrumentation, sample preparation, measurement steps, result calculation and accuracy of the infrared reflection method for measuring the carrier concentration of heavily doped gallium arsenide and indium phosphide. This standard is applicable to the measurement of carrier concentration of heavily doped gallium arsenide and indium phosphide single crystals, and is also applicable to the measurement of carrier concentration of epitaxial layers.
Measurement concentration range:
n-arsenide: 7.0×1016~10×1019cm-3P-phosphide: 2.6×1018~1.3×1020cm*3n--phosphide: 7.0×1016~1.0×1019cm-32Principle
In the infrared region, due to the absorption of carriers, the reflectance spectrum of heavily doped semiconductor materials will have a minimum. This spectrum wavelength minimum has a corresponding relationship with the carrier concentration. The minimum wavelength of the reflectivity spectrum is measured, and the carrier concentration is calculated by the empirical formula.
3 Instruments and equipment
3.1 Infrared spectrometer
Wavelength or wavenumber scanning dispersion type double beam infrared spectrophotometer or Fourier transform infrared spectrometer. a.
Wavelength range 2~100μm, if the wavelength range is larger, the measurement concentration range will be reduced. The repeatability of the wavelength defined in A1 of Appendix A shall be at least 0.05 μn. c.
d. The precision of the wavelength defined in A2 of Appendix A shall be at least ±0.05 μm. e. At 1000 cm-1, the spectral resolution shall be not less than 4 cm~13.2 Instrument accessories
Reflection measurement accessories The incident angle shall not be greater than 30°. 4 Sample preparation
4.1 Bulk material
4.1.1 The surface of the sample to be measured shall be polished to have a good optical surface to ensure that the measurement results can reflect the intrinsic properties of the material.
4.1.2 Comparative measurements shall be carried out on the same part to avoid the influence of sample inhomogeneity. When the sample mobility is abnormally low, the results of this measurement may be inconsistent.
4.2 Other materials
4.2.1 For epitaxial wafers, the wafer thickness must be greater than 1μm. Approved by the Ministry of Machinery and Electronics Industry of the People's Republic of China on March 20, 1989 and implemented on March 25, 1989
SJ3248-89
5 Test steps:
5.1 Refer to 11 and 12 in Appendix 1 to measure the appropriate wavelength clarity and transmission characteristics. 5.2 Place the reflection accessory in the optical path and perform 100% reflection line measurement. 5.3 If the peak-to-valley value of the 100% reflection line of the full coordinate is less than 8%, the measurement result is acceptable. Otherwise, perform 100% line transmission measurement or check the reflection accessory.
5.4 Set the maximum scanning speed according to requirements c, d, and e in 3.1. 5.5 Place the sample with known material type and conductive type on the sample holder. 5.6 Record the reflection spectrum, which will show two reflectivity minima R1 and R2 as shown in the figure. The wavelengths of the short-wavelength and long-wavelength reflectivity minima RI and R2 are called the first (λmin1) and second (λmin2) reflectivity minimum wavelengths, respectively.
6 Calculation of results
Wave number n(em-\)
Determine λmin Schematic diagram
According to the curve of reflectivity and wave number obtained in the test, the carrier concentration λ=1/V is calculated by the following formula.
N=（Aamin）B
Where: N--Carrier concentration (cm-3); λ--Wavelength (μm):
（2）
v--Wave number (cm=1);
λmin--Wavelength corresponding to the reflectivity minimum (um), λmin1 or λmin2, determined by the tested material and its conductivity type, see the table notes. Material
Arsenic image
Monumental image
Arsenic flower edge
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Table calibration constant table
Zi child wavelength (m)
18.5-30,4
339-1000
25.0-1000
A, B-calibration constants are given by the table:
Flower: If there is no "" in the table, take the wavelength of the first minimum reflectivity (in min1) If there is "", take the wavelength of the second minimum reflectivity (in min2) The application wavelength refers to the wavelength range where in min. 7 Report
The report content is as follows:
Measurement conditions;||tt| |Material and conductive model:
Wavelength at the minimum reflectivity;
Carrier concentration;
Sample measurement or location shown in the figure:
Instrument used;
Measurement unit and date;
Name of the measurer.
Calibration constant A
5.803×10-11
2.405×10-*
1.188×10-3
2.592×10-*
5.566×10-1s
4.896×10-
3.784×10-
Calibration constant B
-2-606
-2-6371
8 Accuracy
When the carrier concentration is in the range of 1017~1018cm-3, the measurement precision of n-type arsenide and indium phosphide materials is 4%. 3
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Appendix AbzxZ.net
Definition of wavelength repeatability and accuracy
(reference)
A1 Wavelength repeatability, when measuring the repeatability of a certain absorption or emission band in a given wavelength range, is expressed by dividing the difference between each measurement value and the average measurement value by the number of measurements, that is: p
Wavelength repeatability = (一刘)/n
（1）
λ = (λ:)n, for n measurements The wavelength is the average value, n is the number of measurements, and L is the i-th wavelength measurement value. Where:
A2 Wavelength accuracy is expressed by the deviation between the average value of the wavelength position of a certain absorption or emission band and the theoretical value of the band, that is: Wavelength accuracy ± L…
Where: L is the theoretical value of the absorption band wavelength. (2)
A3 When measuring wavelength repeatability or accuracy, a polystyrene film with a thickness of 300 to 500 μm is selected as the standard sample, and 3.303 μm is used as the reference band for measurement. The number of measurements is 10 times. Additional remarks:
This standard was drafted by the 46th Institute of the Ministry of Machinery and Electronics Industry. The main drafters of this standard are: Li Guanghu, He Xiukun, Wang Qin, Zheng Ju, and Yan Ping.
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