Plasma Enhanced Liquid Source-Cvd Of Ta2O5 using penta Ethoxy tantalum source and its characteristics

Abstract

We rerxprt on plasma enhanced, liquid source, chemical vapor deposition (LS-CVD) of tantalunm penta oxide (Ta 2 O 5 ) material using a penta ethoxy tantalum [Ta(OC 2 H 5 ) 5 ] liquid source. We have investigated several basic plasma deposition conditions such as - dependence of deposition rate and refractive index on the source tank temperature, carrier gas N 2 flow rate, reactive gas O 2 flow rate anid substrate temperature. Structural properties investigated by θ-2θ x-ray measurements showed amorphous nature of the films and Auger electron spectrosopy indicated carbon-contamination free growth of Ta 2 O 5 films having proper stoichiometry (Ta/O = 0.4). In addition to this we have also performed electrical measurements on Au/Ta 2 O 5 /Si MOS structure which exhibit very well defined C-V characteristics with flat band voltage as tow as +0.3V, low leakage current and high breakdown voltages. As a hitherto unreported step in Ta 2 O 5 processing we also performed rapid thermal. Annealing at 700°C and 900°C for 5 minutes which showed much improved electrical properties. All results suggest growth of high quality Ta 2 O 5 films from a carbon-basud Ta liquid source, due to an effect of plasma enhanced deposition process.