Quantitative measurements of two-dimensional ultrashallow B profiles in Si by selective chemical etching

A 2D delineation of ultrashallow B-doped layers was performed by means of selective etch combined with transmission electron microscopy imaging. Specifically, the possibility to extract the active dopant distribution from the profile of the etched region was explored. The etch process was simulated in order to obtain the etch profile evolution and reproduce the experimental data. Good agreement between experimental results and simulated profiles was achieved. Therefore, this experimental technique supported by simulation allows quantitative correlation of die etch depth to the active dopant distribution and the expected etch depth to be calculated for a given dopant profile.