Enhanced dielectric breakdown lifetime of the copper/silicon nitride/silicon dioxide structure

Time-dependent dielectric breakdown (TDDB) of MIS and MIM capacitors with Cu electrodes is investigated. The dielectric breakdown lifetime strongly depends on (1) the material and (2) the electric field strength of the dielectrics in contact with the Cu anode, while the dependence of the TDDB lifetime on the dielectric thickness and the capacitor structure (single-layer or multilayer) is small. In the case of the applied voltage and the total thickness of the dielectrics being constant, the layered SiN-SiO/sub 2/ structure with thinner p-SiN has higher resistance to dielectric breakdown than that of a monolayer structure (SiN, SiO/sub 2/). This higher resistance to breakdown is because of the higher dielectric constant and the higher TDDB endurance of SiN.