STEP COVERAGE AND ELECTRICAL-PROPERTIES OF (BA, SR)TIO3 FILMS PREPARED BY LIQUID SOURCE CHEMICAL-VAPOR-DEPOSITION USING TIO(DPM)(2)

Thin films of (Ba, Sr)TiO3 (BST) with high dielectric constant were prepared on Pt/SiO2/Si substrates of 6-inch-diameter by liquid source chemical vapor deposition using Ba(DPM)(2), Sr(DPM)(2) and TiO(DPM)(2) (DPM = dipivaloylmethanato; C11H19O2) dissolved in tetrahydrofuran (THF). The reproducibility of +/-3% for the film composition was achieved by optimizing the deposition procedures. It was found that the coverage of 72%, obtained at the substrate temperature T-s = 753 K, was better than those obtained using other Ti sources such as Ti(O-i-Pr)(4) (TTIP) and Ti(O-i-Pr)(2)(DPM)(2). The electrical properties of the 480-Angstrom-thick BST film, deposited at T-s = 753 K using TiO(DPM)(2), were as follows: dielectric constant epsilon = 230, equivalent SiO2 thickness t(eq) = 7.8 Angstrom, leakage current density J(L) = 6.7 X 10(-6) A/cm(2) at 1.65 V and dielectric loss tan delta = 0.013.