This Standard was technically approved by the global Photovoltaic Technical Committee. This edition was approved for publication by the global Audits and Reviews Subcommittee on September 12, 2011. Available at www.semiviews.org and www.semi.org in October 2011.

Secondary ion mass spectrometry (SIMS) can measure the total bulk concentrations of oxygen, carbon, boron and phosphorus in polished solar silicon wafers and silicon feedstock. Bulk carbon is important because it can form carbon-related defects, such as SiC inclusions. Bulk oxygen is important in boron-doped silicon because a BO_x defect can degrade cell efficiency. Boron and phosphorus are common dopants in solar Si wafers, and are difficult to measure directly in solar Si wafers, especially in highly compensated silicon.

The measurement of all four elemental concentrations can be accomplished in one test and using one SIMS instrument equipped with a cesium primary ion source.

The SIMS method can be used at three stages of solar Si wafers and silicon feedstock: research and development; process check; and verification at the commercial sales/purchase interface.

SEMI MF2139 — Test Method for Measuring Nitrogen Concentration in Silicon Substrates by Secondary Ion Mass Spectrometry

SEMI PV25-1011 (first published)