Methods of measurement for chromium concentration in semi-insulation Gallium arsenide by infra-red absorption

SJ 3249.3-1989 Infrared absorption test method for chromium concentration in semi-insulating gallium arsenide SJ3249.3-1989 standard download decompression password: www.bzxz.net

Standard of the Ministry of Machinery and Electronics Industry of the People's Republic of China Infrared absorption test method for chromium concentration in semi-insulating gallium arsenide SJ32493-89
1 Main content and applicable scope
This standard specifies the infrared absorption measurement principle, instrumentation, measurement steps, result calculation and accuracy of chromium concentration in semi-insulating gallium arsenide.
This standard is applicable to the determination of Cr concentration in semi-insulating gallium arsenide grown by doped water method, and is suitable for sample thickness of 2~4mm. It is not suitable for samples with chromium concentration greater than 1.5×1017cm-3. 2 Principle
The absorption band caused by the transition from positive 3-valence state to positive 2-valence state in chromium-doped semi-insulating gallium arsenide has a corresponding relationship between absorption coefficient and concentration. The absorption coefficient at 1.3500μm is measured and the concentration is calculated by empirical formula. 3 Instruments and equipment
Spectrophotometer with a range of 0.8~2.5μm or wider. 4 Test steps:
4.1 Use alcohol to polish both sides, and the thickness of the sample is 1~4mm. 4.2 Scan the zero line standard by absorption. If the zero line fluctuation exceeds ±0.002 in the range of 0.8~2.5um, the instrument should be carefully adjusted.
4.3 After the instrument is calibrated, place the sample in the light path and align the light beam to the required measurement position. 4.4 Record the sample absorption spectrum in the wavelength range of 0.8~2.5μm, with the horizontal axis as wavelength λ (μm) and the vertical axis as absorbance A (as shown in the figure).
Wavelength (μm)
Absorption spectrum of chromium-doped gallium dioxide sample by typical horizontal method Approved by the Ministry of Machinery and Electronics Industry of the People's Republic of China on 1989-03-20 2.000
1989-03-25 Implementation
5 Calculation of results
SJ3249.3—89
5, 1 Calculate the chromium content according to the following formula based on the sample absorption spectrum recorded by spectrophotometry. ：Ncr（2.6α-0.46)×1016..
Wherein: Ncr
-chromium content in arsenide image (cm-3);
The absorption coefficient of chromium in arsenide image (cm-1) α is calculated by the following formula
Wherein: A, and A.---the absorbance values ​​corresponding to 1.350μm and 2.0μm in the spectrum; d-sample thickness (cm)
5.2 Semi-insulating Example of calculation of chromium concentration in a typical sample 5.2.1 The sample thickness is 0.154 cm, (1)
5.2.2 The A-in curve obtained from the test is shown in Figure 1, and A, and A, are 0.528 and 0.297 respectively 5.2.3α is calculated by the following formulawww.bzxz.net
0.528-0.297×2.30=3.45(cm-1)g
The chromium content is
6 Report||tt ||The report content is as follows:
7 Accuracy
Sample source and number
Illustrated measurement location
Ncr=（2.6×3.45-0.46）×1016=8.51×1016(cm-3)
αl.35μm and Ncr data
Measurement unit and measurement date
Name of measurer
The measurement accuracy of this method is 5%.
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 Guangping, He Xiukun, Wang Qin, Zheng Ju, Yan Ping-2
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