Introduction. During the last decade the interest in copper passivity significantly increased due to the important role of copper in microelectronic industry. In resent years copper is being evaluated as a replacement for aluminum in integrated circuit interconnects. One of the main steps in copper technology is chemical mechanical planarization (CMP). Determination of CMP slurry chemical composition, which could provide rapid and strong copper passivity, is an important issue for an efficient CMP. None of Cu CMP commercial slurries fulfills the requirement for rapid passivation. The main task of our research is to determine the parameters controlling copper passivity, such as chemical composition of slurry, pH range and the potential region of Cu passivity, which an efficient CMP can be achieved. AFM images of copper surface exposed at 0.2V in K 2 CO 3 solution. AFM images of copper surface exposed at OCP (-0.15 V) in K 2 CO 3 solution. Conclusions Upon immersion 5 min. exposure 30 min. exposure 60 min. exposure Upon immersion5 min. exposure 30 min. exposure 60 min. exposure Without scratchingPeriodically scratched (scriber) surface Potentiostatic behavior of copper in K 2 CO 3 solution. Sharp decrease of anodic current was obtained after applying +0.2 V. This indicates high rate of copper passivity K 2 CO 3 solution. High rate of copper surface re-passivation was observed at periodically scratched surface. Potentiodynamic behavior of copper in solutions containing K 2 CO 3 and KMnO 4 as a oxidizer. 1 mV/s The addition of KMnO 4 increases the OCP potential of copper in 4 gr/l K 2 CO 3 solution. Increase in KMnO 4 concentration shifts the onset of anodic current to more positive potentials. The reverse scan indicates high protection characteristics of the layer which is being formed on copper. The effect of KOH on Cu I-V profile in a solution containing 10 g/l Na 2 SO 4 The effect of K 2 CO 3 on Cu I-V profile of in solutions containing 10 g/l Na 2 SO 4 The effect of K 2 CO 3 on Cu I-V profile of in solutions containing 1 g/l Na 2 SO 4 The effect of K 2 CO 3 on Cu I-V profile Increase in potassium carbonate concentration enhances copper passivity breakdown potential in solutions containing10 gr/l Na 2 SO 4 solution. The values of anodic currents remained less than A/cm 2 in a wide range of potential. Copper repassivation potential in all examined K 2 CO 3 concentrations is ~0.05V Objectives : To study copper passivity in alkaline solutions composed of sodium/potassium hydroxide and sodium/potassium carbonate. To identify the role of pH and different oxidants, such as, H 2 O 2, KMnO 4 and K 2 CrO 4 on Cu passivity. To evaluate the structure and chemical composition of the formed passive film. Experimental: Electrochemical characteristics of copper was performed in a three electrode electrochemical cell equipped with Pt counter electrode and saturated calomel reference electrode. Techniques & Methods: Electrochemical methods: - Potentiodynamic measurements; - Potentiostatic measurements. Surface studies - HRSEM - AFM/STM Increase in potassium hydroxide content enhances copper passivity breakdown potential. The repassivation potential of copper measured in the back scan was 0.0V for all the KOH concentrations (Fig. b). ab Breakdown potential of copper in solutions with K 2 CO 3 concentration above 1 gr/l is ~0.6 V. The values of anodic currents remained less than A/cm 2 in wide range of potential. The effect of reverse scan on Cu I-V profile in 1 gr/l Na 2 SO 4 solution containing 4gr/l K 2 CO 3 (pH 12.6) The reverse scan indicates that at potential range between-0.1 V and 0.8 V, a protective layer is formed at the copper surface. At potentials above 0.8 V, a breakdown of the protective layer occurs and a further increase in the anodic currents indicates that copper is actively dissolved. a b Anodic currents obtained from copper in 1 gr/l K 2 CO 3 solution are less than A/cm 2. Such low anodic currents can be attributed to the formation of a protective layer on the copper surface. Figure b presents reverse scan at different potentials, indicating the strong protective characteristics of the formed layer. 1.The use of basic solution such as alkaline and carbonate based slurries can provide full a passivity to copper surface. 2.The use of carbonate solution with the addition of oxidizer allows rapid formation of a compact and thin passive layer. 3.The passive film formed in carbonate based solution is stable in a wide range of potential (between and 1.00 V). 4.Electrochemical tools in conjugation with in-situ AFM provide a complete understanding of copper passivity.