Lead-scandium-tantalate has been deposited in the perovskite form onto 100mm diameter substrates by liquid injection metal organic chemical vapour deposition at substrate temperatures of 550-600 degreesC. The deposition of the single metal oxides of lead, scandium and tantalum from Pb(thd)(2), Sc(thd)(3), and Ta(OEt)(4)(thd), respectively, have been systematically investigated as a function of substrate temperature and the metal oxide layers have been characterised. The conditions necessary for the formation of perovskite phase of lead-scandium-tantalate have been mapped as a function of perovskite composition and substrate temperature. Crown Copyright