Carbon concentration measurement in silicon down to 10 14 cm ‐3 : second generation IR, SIMS, CPAA and standardization

• Published in: Physica status solidi. C Vol. 13; no. 10-12; pp. 842 - 847
• Main Author: Inoue, Naohisa
• Format: Journal Article
• Language: English
• Published: 01.12.2016
• ISSN: 1862-6351; 1610-1642
• DOI: 10.1002/pssc.201600068

Abstract Carbon concentration ([C]) measurement down to 1×10 14 cm ‐3 was examined by infrared absorption spectroscopy (IR), secondary ion mass spectroscopy (SIMS) and charged particle activation analysis (CPAA). In IR, the reference problem and the phonon problem were solved. By electron irradiation, substitutional carbon C s was converted to IR insensitive interstitial carbon C i . A reference with [C] of about 1×10 14 cm ‐3 which was accurately estimated was produced. Dip and protrusion around the carbon absorption line in the [C] 10 14 cm ‐3 range were identified and a way to cancel them was established. These techniques were transferred to many silicon crystal vendors, IR machine vendors and measurement service companies. SIMS and CPAA measurements were done on the samples measured by IR. The cross calibration was done at [C] = 5×10 14 cm ‐3 and is continued down to 1×10 14 cm ‐3 . Electron irradiation to completely remove C s provides the ideal reference containing effectively no carbon, a new technique to measure the absolute carbon content, and a standard sample for calibration of SIMS and CPAA. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)