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 (atoms/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 10B implant with a certified dose of (1.018 x 1015 0.035 x 1015) atoms/cm2; SRM 2134 contains a 75As implant with a certified dose of (7.330 x 1014 0.028 x 1014) atoms/cm2; SRM 2133 contains a 31P implant with a certified dose of (9.58 x 1014 0.16 x 1014) atoms/cm2. Several examples demonstrate the improved inter-laboratory 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.
Citation: Journal of Vacuum Science and Technology
Pub Type: Journals
arsenic, boron, CRM, ion implantation, neutron activation analysis, phosphorus, silicon, SIMS, SRM