Detection limit of carbon concentration measurement in Si for photoluminescence method after electron irradiation

Abstract

We investigated the detection limit of carbon in Si for the photoluminescence (PL) method after electron irradiation. The detection limit was obtained from the intensity ratio of the G-line to the free exciton line with the G-line intensity twice as high as the noise level and was estimated at 4 × 1013 cm−3 under the measurement condition in accordance with the standard [JIS H0615] for quantification of donor and acceptor impurities in Si at 4.2 K. We showed that the limit is extendable down to 2 × 1013 cm−3 by optimizing the excitation power and sample temperature.

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

“…The detection limit of the C concentration for the method was estimated to be approximately 4 × 10 13 cm −3 . 5) The aims of this paper were to improve the accuracy of the calibration curve and to expand the applicability of the method to Si crystals with wider specifications. In particular we focus on the influence of the O i concentration on the quantitative analysis.…”

Free-to-bound emission from interstitial carbon and oxygen defects (CiOi) in electron-irradiated Si

“…9,10) An accurate lifetime control will be inevitable for high frequency power deices, where the precise management of small amount of residual C and O impurities is necessary. 11,12) The detection of C-and/or G-lines after electron irradiation has been also applied to quantify low-level C impurities: [13][14][15][16][17][18][19][20][21][22][23][24][25] the intensity ratios of these lines to the intrinsic line are used as indexes of the C concentration. This quantification method is being standardized as one of the most sensitive techniques for C in Si.…”