Thin tantalum pentoxide films deposited by photo-induced chemical vapor deposition using an injection liquid source

We report the growth of thin tantalum pentoxide films on Si (100) by ultrav iolet-assisted injection liquid source (UVILS) chemical vapor deposition (C VD) at low temperatures (200-350 degrees C). This new technique combines th e intense radiation from an excimer lamp (lambda = 222 nm) with a novel inj ection liquid source capable of delivering precisely controllable quantitie s of a liquid metalorganic precursor into the CVD chamber. The composition and optical properties of the oxides were determined using a variety of sta ndard characterization methods. After optimization of the deposition parame ters, the best layers were incorporated into simple MOS test structures to enable electrical characterization. Refractive index values of 2.09 +/- 0.0 7, fixed oxide charge content of < 5 x 10(10) cm(-2), breakdown fields high er than 2 MV/cm and dielectric constant values of 18-24 were readily achiev able in the as-deposited films. These properties compare favorably with tho se for layers prepared by conventional thermal-CVD at significantly higher temperatures of 500 degrees C.