BST thin films grown in a multiwafer MOCVD reactor

(Ba0.7Sr0.3)TiO3 thin films with a typical thickness of 30 mn were deposite d on platinized wafers in a planetary multi-wafer reactor combined with a l iquid delivery system. As a direct consequence of the reactor design, we ob tain high film uniformity over 6 inch wafers as well as efficiencies for th e precursor incorporation as high as 40%. The composition and microstructur e of the films were routinely investigated by X-ray diffraction and X-ray f luorescence analysis. Further details of the microstructure were investigat ed by scanning electron microscopy. The electrical properties are character ized in terms of permittivity, loss angle, leakage current and the response to DRAM pulses and characteristic values obtained for depositions at 625 d egreesC include a specific capacitance of 60 fF/mum(2), a tan delta of 0.00 2 and leakage currents in the order of 10(-10) A/cm(2) at 1 V. The electric al properties are discussed in relation to the microstructure and stoichiom etry within a wide range of parameters. (C) 2001 Elsevier Science Ltd. All rights reserved.