MF139100 - SEMI MF1391 - Test Method for Substitutional Atomic Carbon Content of Silicon by Infrared Absorption

 This reference Test Method  covers the determination of substitutional carbon concentration in single crystal silicon. Because carbon may also reside in interstitial lattice positions when in concentrations near the solid solubility limit, the results of this Test Method may not be a measure of the total carbon concentration at such concentrations. The useful range of carbon concentration measurable by this Test Method is from the maximum amount of substitutional carbon soluble in silicon down to about 0.1 parts per million atomic (ppma), that is, 5 × 1015 cm3 for measurements at room temperature, and down to about 0.01 ppma, that is, 0.5 × 1015 cm 3 at cryogenic temperatures (below 80 K). This Test Method utilizes the relationship between carbon concentration and the absorption coefficient of the infrared absorption band associated with substitutional carbon in silicon. At room temperatures (about 300 K), the absorption band peak is at 605 cm1 or 16.53 µm. At cryogenic temperature