Analyzing the channel dopant profile in next-generation FinFETs via atom probe tomography

Abstract

Dopant analysis in next-generation semiconductor devices has become increasingly difficult for traditionally used analytical techniques. Atom probe tomography has been viewed by some as a possible solution to these challenges because of its three-dimensional capabilities, forcing the atom probe to mature at a rapid pace in this particular field. This work presents a well-rounded analysis of how APT can be used to examine B dopant diffusion into the channel of a next-generation FinFET, where the channel dimensions and the number of dopants atoms are significantly smaller than any devices measured by APT to date. Complimentary EELS analysis of the gate and channel provides a better understanding of how distortions and artifacts in the APT reconstruction affect the overall integrity of the dataset. Dopant measurements in the channel are confirmed through in-depth mass spectrum analysis and compared with values proposed by TCAD modeling.