Charging response of back-end-of-the-line barrier dielectrics to VUV radiation

The response of SiN, N-SiC, O-SiC, and SiC dielectrics of varying thickness deposited on Si substrates to irradiation with vacuum ultraviolet (VUV) was compared. The resulting charge was evaluated by measuring the surface potential on the dielectrics after irradiation with 9.5eV photons. The surface potential on all of the dielectrics was positive due to charge accumulation in traps located within the dielectrics. By comparing the surface potential on several thicknesses of dielectrics after VUV irradiation we can determine whether the trapped charges are in the bulk of the dielectric or at the dielectric–substrate interface. ► SiN, N-SiC O-SiC and SiC dielectric films were irradiated with synchrotron radiation. ► The charge was determined from the surface potential after 9.5eV irradiation. ► Location of trapped charges found from surface potential as a function of thickness.