Tantalum Nitride Atomic Layer Deposition Using (tert-Butylimido)tris(diethylamido)tantalum and Hydrazine

Abstract

Tantalum nitride atomic layer deposition (ALD) was performed using sequential exposures of (tert-butylimido)tris(diethylamido) tantalum (TBTDET) and either hydrazine or ammonia . X-ray reflectivity studies demonstrated that hydrazine consistently yielded films with larger growth rates and higher densities than the films grown using ammonia. The ALD growth rate of using hydrazine was higher than the growth rate obtained using ammonia over the temperature range from . Quartz crystal microbalance measurements were also used to confirm the ALD growth rates and to verify the self-limiting behavior of each reactant. Hydrazine yielded a density of at that was significantly greater than the highest density of obtained at with ammonia. In situ resistivity measurements on the ALD films grown using hydrazine at obtained resistivities of at and after annealing to . The surface species and reaction products during the sequential exposures of TBTDET and hydrazine at were examined using Fourier transform infrared spectroscopy and quadrupole mass spectrometry. These studies allowed a growth mechanism to be proposed for ALD using TBTDET and hydrazine.