Deposition and annealing of tantalum pentoxide films using 172 nm excimer lamp

We report the growth of thin tantalum pentoxide films on Si(100) by photo-a ssisted chemical vapor deposition (photo-CVD) from a tantalum ethoxide sour ce using an excimer lamp (Xe-2(*), 172 nm). The effects of substrate temper ature and ultraviolet (UV) annealing on the film formed have been studied u sing ellipsometry and Fourier transform infrared spectroscopy (FTIR) measur ements. Tnt: FTIR spectra reveal suboxide formation in the as-deposited fil ms that disappeared after subsequent UV annealing. The electrical propertie s of the films were determined by capacitance-voltage (C-V) and current-vol tage (I-V) techniques on A1/Ta2O5/Si metal oxide semiconductor structures. The I-V characteristics of both as-deposited and annealed Alms can be descr ibed by the Fowler-Nordheim tunneling mechanism. Dielectric constant values of about 24 were readily achievable in the as-deposited films that are com parable to those obtained by other techniques. (C) 2000 Published by Elsevi er Science B.V. All rights reserved.