Study of boron detection limit using the in-air PIGE set-up at LAMFI-USP

• Main Authors: Moro, M V, Silva, T F, Trindade, G F, Added, N, Tabacniks, M H
• Format: Conference Proceeding
• Language: English
• Subjects: ALPHA PARTICLES; Beans; BERYLLIUM 7; BORON; BORON 10 TARGET; CONCENTRATION RATIO; Contaminants; Emission analysis; Gamma rays; ICP MASS SPECTROSCOPY; Inductively coupled plasma mass spectrometry; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; KEV RANGE; Low concentrations; Mass spectrometry; Materials science; Metallurgy; Nuclear engineering; Nuclear power plants; NUCLEAR REACTION ANALYSIS; Nuclear safety; Photovoltaic cells; PROMPT GAMMA RADIATION; PROTON REACTIONS; QUANTITATIVE CHEMICAL ANALYSIS; SEMICONDUCTOR MATERIALS; SENSITIVITY; Shielding; SILICON; Solar cells
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/1.4901776

The quantification of small amounts of boron in materials is of extreme importance in different areas of materials science. Boron is an important contaminant and also a silicon dopant in the semiconductor industry. Boron is also extensively used in nuclear power plants, either for neutron shielding or for safety control and boron is an essential nutrient for life, either vegetable or animal. The production of silicon solar cells, by refining metallurgical-grade silicon (MG-Si) requires the control and reduction of several silicon contaminants to very low concentration levels. Boron is one of the contaminants of solar-grade silicon (SG-Si) that must be controlled and quantified at sub-ppm levels. In the metallurgical purification, boron quantification is usually made by Inductive Coupled Plasma Mass Spectrometry, (ICP-MS) but the results need to be verified by an independent analytical method. In this work we present the results of the analysis of silicon samples by Particle Induced Gamma-Ray Emission (PIGE) aiming the quantification of low concentrations of boron. PIGE analysis was carried out using the in-air external beam line of the Laboratory for Materials Analysis with Ion Beans (LAMFI-USP) by the 10B(p,αγ(7Be nuclear reaction, and measuring the 429 keV γ-ray. The in-air PIGE measurements at LAMFI have a quantification limit of the order of 1016 at/cm2.