Tricyclazole (TCA), a nitrogen-containing heterocyclic compound, is employed as potential leveler for microvia filling with electroplating copper. The leveler is characterized by quantum chemical calculations, molecular dynamics simulations, electrochemical measurements, Field-Emission Scanning Electron Microscope (FE-SEM), and X-ray photoelectron spectroscopy (XPS). The quantum chemical calculations and molecular dynamics simulations results indicate that TCA has abundant active sites and strong adsorption capacity on the copper surface. Thus, TCA may predict as leveler for microvias filling. The electrochemical impedance spectroscopy (EIS) and cathodic polarization curves measurements results show that the adsorption of TCA on the copper surface inhibit copper deposition and the cathodic potential is reduced effectively from -0.02 V to -0.24 V. The XPS measurements reveals that the strong donor-acceptor interaction between TCA and the copper surface due to the formation of Cu(I)TCA complex or polymeric complexes. In order to verify that the structure of the leveler with nitrogen-containing heterocyclic determines the filling performance, 2-amino-4-methylbenzothiazole (AMBT) is used for comparison. Notable, TCA used as a leveler has achieved the superfilling of microvias under the synergistic effect of various additives. These results evidence TCA as a promising leveler for filling electroplated copper microvias.