Characteristics of HfN Films Deposited by Using Remote Plasma-enhanced Atomic Layer Deposition

Abstract

HfN films were deposited by using remote plasma-enhanced atomic layer deposition (RPALD) with tetrakis-dimethylamino-hafnium {TDMAH, Hf[N(CH(3))(2)](4)} as a Hf precursor and a N(2) plasma as a reactant. The growth rate of the HfN films was about 0.2 nm/cycle in the process window of 150 - 250 degrees C The optimized process temperature, plasma power, and pressure were 250 degrees C, 300 W, and I Torr, respectively. The as-deposited film was slightly nitrogen-rich, and the nitrogen content decreased slightly after in-situ vacuum annealing at 700 degrees C for 10 min. HfN films deposited on contact holes (0.12-mu m wide and 1.8-mu m deep) showed excellent conformal coverage. Barrier characteristics were observed in the Cu/HfN/Si samples after annealing at various temperatures, and the formation of a copper silicide phase was observed after annealing at 650 degrees C.