Determination of Low C Concentration in Czochralski-Grown Si for Solar Cell Applications by Liquid-N-Temperature Photoluminescence After Electron Irradiation

Self Cite

As an extension of the standardization of the photoluminescence method after electron irradiation [Tajima et al., Jpn. J. Appl. Phys. 59, SGGK05 (2020)], we present the calibration curve for quantifying C impurities ranging from 1 × 1014 to 3 × 1015 cm−3 in Czochralski-grown Si with resistivity higher than 50 Ω · cm (n-type) and than 5 kΩ · cm (p-type) and with the O concentration of 1.5 × 1017 cm−3. The intensity ratio of the G-line to the intrinsic emission normalized by the ratio of the reference sample was used as an index of the C concentration. The curve was determined as quadratic formulas by the substantial agreement between the theory and the experimental data, which allowed us to expand the applicability of the curve to the O concentration range up to 5.5 × 1017 cm−3. We showed that the relative root-mean-square discrepancy of the C concentration from values determined by secondary ion mass spectroscopy was 16%.

Section: Theoretical Backgroundmentioning

confidence: 99%

Calibration curve for the photoluminescence method after electron irradiation for quantifying low-level carbon in silicon

Tajima¹,

Samata²,

Nakagawa³

et al. 2021

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“…Quantitative analysis of the C impurities has been proposed based on the positive correlation between the C concentration and the Gline intensity. [15][16][17][18][19][20][21][22][23][24][25][26] Nakamura et al 17) derived the C i C s concentration (N G ) based on the defect reaction model. 27) The irradiation of MeV electrons (e − ) produces vacancies (V ) and self-interstitials (Si i )…”

Section: Theoretical Backgroundmentioning

confidence: 99%

Extension of the scope of the photoluminescence method after electron irradiation for quantifying low-level carbon in silicon

Tajima,

Samata,

Nakagawa

et al. 2024

Self Cite

We have extended the applicability of the photoluminescence method after electron irradiation for quantifying low-level C impurities in Si crystals. The intensity ratio of the G-line to the intrinsic emission normalized by the ratio of the reference sample is used as an index of the C concentration. The calibration curves have already been established for Czochralski-grown crystals with resistivity higher than 50 Ω·cm (n-type) and higher than 5 kΩ·cm (p-type). We showed that the method was extendable to the resistivity range down to 30 Ω·cm in n-type samples with the O concentration in the range 1-6×1017 cm-3. The extension to float-zone (FZ) crystals was realized by using the theoretical relationship between the C concentration and the G-line intensity ratio normalized by the ratio of the FZ reference sample. Regarding the extension to conductive p-type B-doped samples, the formation of B-related radiation-induced defects was found to be an obstacle.

“…We choose the appropriate electron irradiation condition based on the previous works. [13][14][15][16][17] While it had been taken for granted that the PL measurement was performed at liquid He temperature, one of the authors (MT) reported that the detection of the C-and G-lines is possible at liquid nitrogen temperature [21][22][23] and that the Cline-related broad band termed the C08 band is observable at room temperature. 24,25) It should be noted that both the G-and C-line intensities are influenced by the O i concentration.…”

Section: Theoretical Backgroundmentioning

confidence: 99%

Round-robin test of the photoluminescence method after electron irradiation for quantifying low-level carbon in silicon

Tajima

Samata

Nakagawa³

et al. 2020

Round-robin test of the photoluminescence method after electron irradiation was performed for quantifying low-level C impurities in the magneticfield-applied Czochralski Si crystals with a resistivity of about 50 Ω•cm (n-type) and with resistivity higher than 5 kΩ•cm (p-type). Their C concentrations were determined as ranging from 1.4 × 10 14 to 3.6 × 10 15 cm −3 by secondary ion mass spectroscopy. A universal correlation holds between the C concentration and the intensity ratio of the G-line to the band-edge emission normalized by the ratio of the reference sample, which can be used as a calibration curve for the C quantification. The measurement error and repeatability of the G-line intensity ratio are less than ±20% and less than ±10% deviation, respectively, and the overall error in the C concentration estimated from the calibration curve is less than ±30%. This demonstrates the effectiveness of the present method as a novel standard technique for quantifying low-level C impurities.