A copper drift-model for the low-/spl kappa/ polymer DVS-BCB

To prove the reliability of DVS-BCB (Benzocyclobutene) as an interlevel-dielectric in copper-metallization-systems we investigated the extreme low copper drift rate in this spin-on-polymer. BTS-Sequences (B_ias-T_emperature S_tress) were applied to accelerate the copper drift in the polymer. Using experimentally obtained data, an equation was created to compute the copper drift rate in the DVS-BCB as a function of the applied voltage and the temperature of the polymer. The copper drift rate in the DVS-BCB, Metal-Insulator-Substrat-structures (MIS) were determined by Capacitance-Voltage-measurements (CV). The results obtained by this method are supported by a Secondary ion Mass Spectroscopy-analysis (SIMS). A linear relationship between the logarithmic copper drift rate as a function of the applied voltage and the temperature of the polymer was determined. The experimental data used to establish the equation of the drift rate covers temperatures and electrical conditions used in integrated circuits under operation.