Three dimensional characterization of dopant distribution in polycrystalline silicon by laser-assisted atom probe

Dopant distribution in polycrystalline Si of n-type metal-oxide-semiconductor field effect transistor was measured by laser-assisted three dimensional atom probe. Segregation of As and P atoms to grain boundaries and at the interface between gate and gate oxide, resulting from different mechanisms, i.e., volume diffusion in the bulk and grain boundary diffusion at the interface, was clearly observed. Concentration profiles that show such clear segregation were directly obtained by atomic-resolution measurement.