This standard applies to the measurement of carrier concentration in doped gallium arsenide single crystals. GB/T 8757-1988 Plasmon resonance measurement method for carrier concentration in gallium arsenide GB/T8757-1988 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Measurement Method of Carrier Concentration in Gallium Arsenide by the Plasma Resonance Minimum
Determination of Carrier Concentration in Gallium Arsenide by the Plasma Resonance Minimum This standard applies to the measurement of carrier concentration in doped gallium arsenide single crystals. Measurement range: n-GaAs1.0×107～1.0×10\cm-;p-GaAs 2. 0 × 10\~1. 0 X 10 cm-s1Principle
UDC 661. 868. 1
GB 8757--88
In the infrared spectrum region, the reflectivity of heavily doped semiconductor materials is a function of wavelength. The carrier concentration and the wavelength of the minimum reflectivity have a corresponding relationship. The wavelength of the plasma resonance minimum of the reflectivity spectrum is measured, and the carrier concentration is calculated according to the calibration formula. 2 Sample requirements
2.1 The surface of the semiconductor material sample needs to be mechanically or chemically polished to ensure that it has a good optical surface. 2.2 The conductivity type of the sample shall be known. 3 Instruments and accessories
3.1 Instruments
3.1.1 Double-beam infrared spectrophotometer or Fourier transform infrared spectrometer with wavelength or wave number display. 3.1.2 Wavelength range 2.5~~50μm (4000~~200cm-1). If the wavelength range is narrower, the measurement range is correspondingly reduced. 3.1.3 Wavelength repeatability and wavelength accuracy shall be at least 0.05um. 3.1.4 At 1000cm-, the spectral resolution shall be 2cm- or less. 3.2 Accessories
3.2.1 Reflection accessories matching the spectrophotometer, with an angle of incidence not greater than 30°. 3.2.2 Aperture: It shall be made of non-reflective black body material with various apertures. 4 Measurement steps
4.1 Spectrophotometer calibration
4.1.1 Determine wavelength accuracy and repeatability. Measure the absorption spectrum of polystyrene film with a thickness of 300~500μm, and use the 3.303μm absorption band as the measurement reference band. Measure 10 times, and the result should meet the requirements of 3.1.3. 4.1.2 Place the reflection accessory in the optical path to measure the 100% line, and its valley value should be less than 8%. 4.2 Measurement
4.2.1 Measure the reflection spectrum of the sample.
4.2.2 The scanning speed of the measurement should meet the requirements of 3.1.3 and 3.1.4. 4.2.3 If the difference between the reflection at the minimum and the maximum reflection on either side is less than 10%, the Y-axis coordinate should be expanded and re-drawn. China Nonferrous Metals Industry Corporation Approved on February 4, 1988, and implemented on February 1, 1989
GB 8757--88
4.2.4 Draw two straight lines tangent to the curve at a distance of no more than 100 cm on both sides of the reflectivity curve. The intersection of the two straight lines is the position of the reflection minimum.
5 Calculation of measurement results
5.1 Calculate the carrier concentration according to the following calibration formula based on the measured minimum wavelength. N- (AAmin+C)R
Wherein: N-
Carrier concentration, cm-\,
Input minimum reflectivity wavelength, um;
A, B are constants, listed in Table 1;
C=0 (for gallium arsenide).
Table 1A, B constants
Applied wavelength
9. 418. 5
>18. 5~30. 4
>30. 4~33. 9
>33. 9~～100
Note: The ones with (*) are the calibration formulas corresponding to the second reflection minimum wavelength. 6 Precision
5.803X10m1
2. 405 × 10 -1
1.188 × 10-1
2. 592 X 10 -°
5. 566 ~～~ 10
—12.308
—2.5017
The precision of this standard for n-type gallium arsenide materials in multiple laboratories is 4.85% (2s). The precision of p-type gallium arsenide materials in multiple laboratories is 4.68% (2s).
Test report
The test report should include the following contents:
Instrument used;
Material and its conductivity type;
Wavelength of reflection minimum;
Carrier concentration;www.bzxz.net
Graphical sample measurement location.
Additional Notes:
This proposal was drafted by Beijing General Research Institute of Nonferrous Metals. The main drafter of this proposal was Bao Jianying.
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