Frequently it is essential to control the boron level in heavily-doped n-type substrates used to make epitaxial wafers because the boron contamination can result in autodoping at the epitaxial silicon-substrate interface.

SIMS can measure the boron contamination in heavily-doped n-type substrates.

This Test Method can be used for process control, research and development, and materials acceptance purposes.

This Test Method covers the determination of total trace boron contamination in the bulk of single crystal, heavily doped n-type silicon substrates using secondary ion mass spectrometry (SIMS).

This Test Method can be used for silicon in which the dopant concentrations are less than 0.2%
(1 × 1020 atoms/cm3) for antimony, arsenic or phosphorus doping. This Test Method is especially applicable for silicon where boron is an unintentional p-type contaminant at trace levels (<5 × 1014 atoms/cm3).

This Test Method can be used for silicon in which the boron contamination is greater than two times the SIMS detection limits that is approximately between 5 × 1012 atoms/cm3 and 5 × 1013 atoms/cm3 depending upon the instrumentation type.

In principle, different sample surfaces can be used, but the precision estimate was taken from data on polished etched surfaces.

SEMI M59 — Terminology for Silicon Technology