Microstructure of Cu film sputter deposited on TiN

The correlation between the microstructure of Cu films and the deposition c onditions of the sputtering method was investigated to obtain larger grain size and higher(111) texture. Cu film was deposited on SiO2 and TiN by vary ing substrate temperature, Ar gas pressure, and rf power. It is found that the texture of the Cu film has very little dependence on the deposition con ditions. The Cu grains are more oriented to (111) on a TiN substrate than o n a SiO2 substrate, and the (111) ratio of the Cu films on the TiN substrat e increases as the (111) ratio of the TiN film is increased. The maximum in crease in grain size was tenfold by reducing the Ar pressure from 3 to 1 mT orr, fivefold by increasing the deposition temperature from room temperatur e to 300 degreesC, and twofold by increasing the sputtering power from 1.1 to 4.4 W/cm(2) Thus, it is revealed that the lowering of Ar gas pressure is the dominant factor for enlarging the grain size. An increase in the energ y of Cu particles brought about by reducing the Ar gas pressure is discusse d as one of the factors contributing to the increase in the grain size. (C) 2000 American Vacuum Society. [S0734-2101(00)01706-1].