Preparation of SrTiO3 films on 8-inch wafers by chemical vapor deposition

SrTiO3 films were grown on 8-inch-diameter Si substrates by chemical vapor deposition [CVD] using bis(dipivaloymethanato) strontium [Sr(DPM)(2)], titanium tetraisopropoxide [Ti(OiPr)(4)] and O-2. We have developed an oil-circulating showerhead-type nozzle to prevent condensation and decomposition of source materials. Conditions of supplying Sr(DPM)(2) were investigated with respect to cylinder pressure and the charge in the cylinder, using a simple vapor transport system. The deposition rate of SrTiO3 films on 8-inch wafers was improved to 2nm/min by increasing the charge in the source cylinder and decreasing the cylinder pressure. A thickness uniformity of 3.4% and a composition uniformity of 4.6% were obtained by complete mixing of gases. A step coverage of 85% was obtained using Sr(DPM)(2), titanyl bis(dipivaloylmethanato) [TiO(DPM)(2)] and N2O.