Analysis of implanted silicon dopant profiles

Atom probe tomography implant dose measurements are reported for National Institute of Standards and Technology Standard Reference Material 2134 (arsenic implant). Efforts were taken to manufacture specimens with limited variation in size and shape to minimize variation in physical reconstruction parameters. A tip profile reconstruction was utilized where measurements of tip profile, post-analysis specimen radius and sphere-to-cone radius ratio were required as inputs into the reconstruction process. A variation of 4% is observed in the dose measurement under these conditions. Various considerations necessary to narrow the observed variation in measured dose, toward the limit imposed by counting statistics, are discussed.

► Multiple APT measurements were made on a NIST standard reference implant material.
► Accuracy and precision of APT was assessed on implant dose measurements.
► Dose standard deviations of ∼2% (∼2× counting statistics limit) were achieved.
► SEM exposure was found to affect the ability to successfully analyze these specimens.