The effect of NH₃ plasma pulse time on atomic layer-deposited TiN films using tetrakis-(dimethylamino) titanium as a metal precursor

Abstract

The growth of TiN films by plasma-enhanced atomic layer deposition is investigated using tetrakis-(dimethylamino) titanium and NH 3 . In particular, the influence of the NH 3 plasma pulse time on the deposited film is discussed in detail. It is found that the film resistivity decreases monotonically to 4.6 × 10 −4 Ω • cm by increasing the NH 3 plasma pulse time to 25 s, then shows an increase. The former trend is ascribed to some competitive reactions dominated by N radicals and residual O 2 , i.e., more N radicals originating from longer NH 3 plasma pulses produce more Ti-N bonds and restrain the formation of Ti-O and Ti-C bonds in the deposited film. The latter trend is attributed to the generation of additional Ti, N, and C active sites at the saturated bonding surface due to plasma ion bombardment; these can react with residual O 2 , producing more C-O and Ti-O bonds.Smooth, ultra-thin TiN films (<3 nm) are also successfully demonstrated.

Plasma-Enhanced Atomic Layer Deposition of Low Resistivity and Ultrathin Manganese Oxynitride Films with Excellent Resistance to Copper Diffusion

“…29 This thus leads to the incorporation of O element in the deposited film. In addition, Ding et al 30 reported that the amount of O incorporated into the TiN film also correlated with the pulse time of NH 3 plasma while using Ti[N(CH 3 ) 2 ] 4 and NH 3 reactants, that is, a shorter or longer pulse of NH 3 plasma would cause an increase in the percentage of O in the TiN film. Accordingly, the amount of O in the MON film might be further reduced by optimizing the pulse time of NH 3 plasma.…”