Aluminum chemical vapor deposition with new gas phase pretreatment using tetrakisdimethylamino-titanium for ultralarge-scale integrated-circuit metallization

A new gas phase pretreatment method was developed for blanket Al chemical vapor deposition (CVD) used in ultralarge-scale integration metallization. This method uses a halogen-free Ti compound. The pretreatment process involves exposing substrates to a tetrakisdimethylamino-titanium atmosphere before the Al CVD. This significantly lowers the deposition temperature of CVD using dimethylaluminum-hydride, and thus Al films can be deposited on SiO2 even at 160 °C, where deposition would otherwise not occur. The deposited Al films have superior surface morphology due to higher Al island density in the early growth stage. Using this technique, V-shaped trenches with an opening width of 0.4 μm and a depth of 1.2 μm are successfully filled with Al.