Nonlinear calibration curves in secondary ion mass spectrometry for quantitative analysis of gesi heterostructures with nanoclusters

Abstract

For the first time in the practice of secondary ion mass spectrometry, we obtained a nonlinear calibration curve for the ratio of the cluster and elementary secondary ions of germanium Ge₂/Ge without secondary ions of silicon, which enables the quantification of germanium in Ge_xSi_1–x heterostructures in the entire range of 0 < x ≤ 1. We developed a method for quantitative lateral analysis based on the plotting of a lateral map of x. An algorithm to identify and analyze the lateral heterogeneity of x in Ge_xSi_1–x heterostructures with 3D clusters by comparing the results of depth profiling analysis, obtained using linear and nonlinear calibration curves, is developed, and concentration x in the self-assembled nanoislands is determined.