Development of certified reference materials of ion-implanted dopants in silicon for calibration of secondary ion mass spectrometers

Certified reference materials have been developed for calibration of the concentrations of the most common dopants used in silicon semiconductor technology—boron, arsenic, and phosphorus. These materials consist of a single dopant species that is introduced into a silicon wafer by ion implantation. The certified dose (at.∕cm2) of the dopant species is used for calibration of dopant concentration measurements with secondary ion mass spectrometers. Certification measurements were carried out by nuclear analytical methods—neutron depth profiling for boron, instrumental neutron activation analysis for arsenic, and radiochemical neutron activation analysis for phosphorus. SRM 2137 contains a B10 implant with a certified dose of (1.018×1015±0.035×1015)at.∕cm2; SRM 2134 contains a As75 implant with a certified dose of (7.330×1014±0.028×1014)at.∕cm2; SRM 2133 contains a P31 implant with a certified dose of (9.58×1014±0.16×1014)at.∕cm2. Several examples demonstrate the improved interlaboratory agreement that is achievable in the measurement of unknown dopant concentrations and implanted doses when these reference materials are used for calibration by each laboratory.