Chemical Etching and Plating Characteristics of Vapor Deposited Copper Film Using High Purity Copper Sources

Cu 99.99mass% (4N) and Cu 99.9999mass% (6N) copper source metals were used for vapor deposition to consider the effects of the purity of the source metal on the photochemical etching and electroplating of vapor deposited copper. In comparison to film deposited using a 4N copper source, the film deposited using a 6N source exhibited superior etching pattern wall smoothness in photochemical etching and was free from dendrite growth in nickel plating. X-ray diffraction analysis showed no difference in copper crystal orientation between films formed with the 4N and 6N sources. Sputtering AES however, showed that there was less oxygen content in the copper surface deposited using the 6N copper source.