Publication

Abstract : pA method of fabricating a semiconductor device having a Cu—Ca—O thin film formed on a Cu surface by immersing the Cu surface into a unique chemical (electroless plating) solution containing salts of calcium (Ca) and copper (Cu), their complexing agents, a reducing agent, a pH adjuster, and surfactants; and a semiconductor device thereby formed for improving Cu interconnect reliability, electromigration resistance, and corrosion resistance. The method controls the parameters of pH, temperature, and time in order to form a uniform conformal Cu-rich Cu—Ca—O thin film, possibly containing carbon (C) and/or sulphur (S), for reducing electromigration in Cu interconnect lines by decreasing the drift velocity therein which decreases the Cu migration rate in addition to decreasing the void formation rate. The method for forming a semiconductor device having a copper-calcium-oxide (Cu—Ca—O) thin film on a copper (Cu) surface, the Cu surface having been formed by CVD, PVD, or electroplating, by treating the Cu surface in a chemical solution, comprises the steps of: (1) providing the chemical solution which comprises: (a) at least one calcium (Ca) ion source for providing a plurality of Ca ions; (b) at least one complexing agent for complexing the plurality of Ca ions; (c) at least one copper (Cu) ion source for providing a plurality of Cu ions; (d) at least one complexing agent for complexing the plurality of Cu ions; (e) at least one pH adjuster; (f) at least one reducing agent for facilitating deposition of the plurality of Cu ions; (g) at least one wetting agent for stabilizing the chemical solution; and (h) a volume of water, (a) through (g) being dissolved in (h); (2) immersing the Cu surface in said chemical solution, thereby forming the Cu—Ca—O thin film on the Cu surface; and (3) rinsing the Cu—Ca—O thin film formed on the Cu surface in water; drying the the Cu—Ca—O thin film formed on the Cu surface under a nitrogen flow (GN2); and completing formation of the semiconductor device./p