STRONTIUM BISMUTH TANTALATE THIN FILM DEPOSITION BY LIQUID-DELIVERY MOCVD USING NOVEL LIQUID BISMUTH PRECURSORS

ABSTRACT Novel liquid bismuth precursors (triallylbismuth (Bi(CH2CH═CH2) and tributylbismuth (Bi(C4H9)3)) were tested for metalorganic chemical vapor deposition (MOCVD). Strontiumbis-pentaethoxy methoxyethoxy tantalate (Sr[Ta(OEt)5(OC2H4OMe)]2) was used as Sr-Ta source. The growth rates were ≤10 nm/h for triallylbismuth and for triphenylbismuth, ≤1000 nm/h for tributylbismuth, and ≤60 nm/h for Sr[Ta(OEt)5(OC2H4OMe)]2. The deposition rate of SBT was always lower than the rate of bismuth oxide. A decrease of the deposition pressure improved uniformity of the film thickness but reduced the deposition rate of the films. XPS depth profiling indicated more metallic bond characteristics of Ti, Sr, and Bi after ion bombardment.