Low-resistivity tantalum nitride (TaN) films were deposited by low-pre
ssure metal-organic chemical vapor deposition (MOCVD) using a new prec
ursor tertbutylimidotrisdiethyl amidotantalum. The surface morphology
and the step coverage of TaN films were characterized by scanning elec
tron microscopy. The film deposited at 450 degrees C had nearly 100% s
tep coverage and the step coverage decreased to 25% for the films depo
sited at 650 degrees C, The carbon and oxygen concentrations are about
10 at.% in the CVD TaN films, as determined by Auger electron spectro
scopy. From Rutherford backscattering spectroscopy and secondary ion m
ass spectroscopy analysis, TaN films were found to be effective diffus
ion barriers between aluminum and silicon up to 550 degrees C. The ele
ctrical measurements of diode-leakage current indicate that the Al/TaN
/Si structure remained stable up to 500 degrees C, after which Al star
ted to diffuse through the TaN layer and resulted in a higher leakage
current.